Invasive alien insects, as dangerous pests in newly introduced areas, present challenges such as delayed detection, difficult monitoring, rapid outbreaks and incomplete eradication. These issues have long been the emphases and difficulties in the field of biosecurity worldwide. In this article, we made an overview of the major progress in the studies on the mechanisms of population outbreak and causing disaster, monitoring and early warning technologies, and control measures for invasive alien insects in China. We also summarized and introduced the main contents of this special issue from three aspects: The researches on population dynamics monitoring, mechanisms of insect resistance, and green control technologies for pest insects. Finally, we prospected the development trends of standardization, informatization, intelligence, and greening of monitoring and control of invasive alien insects in the future, and proposed the key directions for future control and management strategies for these pests, in order to promote more efficient, integrated and sustainable control approaches through technological innovation.

【Aim】To explore the role of heat shock protein Hsp70 genes of Myzus persicae in response to high and low temperature stress. 【Methods】 RT-qPCR was used to detect the relative expression levels of eight MpHsp70 genes (MpHsp70-1, MpHsp70-2, MpHsp70A1, MpHsp70B2, MpHsp68a, MpHsp68b, MpHsc70-4 and MpHsp70) in different wingless adult tissues (head, midgut, embryo and cuticle) and wingless adults under high temperature (36 ℃) and low temperature (4 ℃) stress for different duration (0, 30, 60, 90, 120 and 150 min), respectively. RNAi was used to silence two key MpHsp70 genes (MpHsp70A1 and MpHsp68a), and the survival rate and number of nymphs produced of wingless adults were observed and calculated at 120 min under high temperature treatment (36 ℃) and 30 min under low temperature treatment (4 ℃).【Results】 The eight MpHsp70 genes were expressed in different wingless adult tissues of M. persicae, and the expression levels of MpHsp70, MpHsp70A1, MpHsp70B2, MpHsc70-4 and MpHsp68b in the cuticile were significantly higher than those in the other tissues. The expression levels of MpHsp70-1, MpHsp70-2 and MpHsp68a in the embryo of M. persicae were significantly higher than those in other tissues. High and low temperature stress had significant induction effect on the expression of MpHsp70 genes in wingless adult of M. persicae. The expression levels of MpHsp70-1, MpHsp70A1, MpHsp70-2, MpHsp68a and MpHsp68b all increased and then decreased under 4 ℃ stress, and reached the highest at 30 min under 4 ℃ stress, which were significantly higher than those of the control. Under 36 ℃ stress, the expressions levels of MpHsp70-1, MpHsp70A1, MpHsp70-2, MpHsc70-4, MpHsp68a and MpHsp68b increased first and then decreased. The expression level of MpHsp70-1 reached the highest at 60 min after 36 ℃ stress, and those of the other genes reached the highest at 120 min after 36 ℃ stress. After the silence of MpHsp68a, the survival rate and number of nymphs produced of M. persicae under high and low temperature stress were significantly decreased and those after the silence of MpHsp70A1 under high temperature stress were extremely significantly decreased as compared with those of the control group. 【Conclusion】MpHsp70 genes of M. persicae can respond to high and low temperature stress, and play an important role in the molecular mechanism of resistance to temperature stress of M. persicae.
Key words: 

 Tomato is one of the most important horticultural crops, and China is the largest producer of tomato in the world. In recent years, the tomato industry is facing increasingly severe pest threats including the traditional important pests (Bemisi tabaci, Frankliniella occidentalis and Helicoverpa armigera) and the newly emerged invasive pest Tuta absoluta. Elucidating the defensive mechanism of tomato especially wild tomato germplasm resource, which has significantly higher resistance to pests, can provide important genetic resources for breeding process of insect-resistant tomato varieties. Meanwhile, the key insect-resistant metabolites of tomato can also offer valuable insights into the development of new safer and more eco-friendly botanical pesticides. In this article, we summarized the interactions between tomato pests and host plants like tomato across multiple levels of insect resistance mechanisms in plants. Key topics include: (1) the recognition of saliva proteins from piercing-sucking and chewing insects by tomatoes and its impact on anti-insect immunity; (2) the signal transduction networks of insect resistance and the regulatory mechanisms of core defense-related transcription factors in tomato; (3) structural and metabolic bases of insect resistance in plants, such as trichomes, acylsugars, phenolamides, steroidal alkaloids, and volatile compounds, which respond to pest attacks and confer insect resistance through molecular and ecological pathways. Future research should leverage emerging technologies like single-cell transcriptomics and spatial transcriptomics, combined with gene editing and genetic manipulation tools, to further clarify the signaling pathways of insect resistance and the synthesis and regulation of defense compounds in tomato. These efforts will deepen our understanding of plant-insect interactions and lay a theoretical foundation for breeding high-yield, insect-resistant tomato varieties.

 【Aim】 The small cocoon mutant sc was discovered among the offspring of space silkworm (Bombyx mori), exhibiting slow larval development and reduced consumption of mulberry leaves. We speculate that genes related to growth and development pathways of the sc mutant may be affected by the gene mutation. Our previous research indicated that the sc mutant is controlled by a pair of recessive genes located on the 3rd linkage group of B. mori, but the responsible gene has not yet been identified. This study aims to provide insights into the identification of the responsible gene for the sc mutant and the analysis of its molecular mechanisms through comparative transcriptomic analysis between the sc mutant and the normal cocoon strain (TG) derived from space B. mori.【Methods】 The head and midgut tissues from the day-4 5th instar larvae of sc and TG were collected for transcriptome sequencing (RNA-seq), respectively. The differentially expressed genes (DEGs) were obtained by comparative transcriptome analysis. Then GO annotation and KEGG enrichment analysis of DEGs were performed. qRT-PCR was employed to validate the expression levels of randomly selected DEGs in sc and TG and investigate the expression levels of the genes of interest in sc. 【Results】 A total of 1 528 DEGs were detected in heads in the comparison group TG vs sc, with 820 DEGs showing up-regulated expression and 708 DEGs showing down-regulated expression. Similarly, 1 401 DEGs were identified in the midguts of the comparison group TG vs sc, with 683 DEGs showing up-regulated expression and 718 DEGs showing down-regulated expression. The GO analysis indicated that in biological processes, the majority of DEGs in the head and midgut were implicated in cellular process, metabolic process, biological regulation, response to stimulus, etc. In terms of molecular functions, most DEGs were associated with binding, catalytic activity, structural molecule activity, transporter activity and ATP-dependent activity. DEGs in the head and midgut were implicated in signaling pathways associated with the growth and development of B. mori, including the Hippo, Insulin and mTOR pathways. The qRT-PCR analysis revealed that the gene expression trend was consistent with the transcriptome sequencing result, and compared to TG, the sc mutant had the key genes BMSK0008105, BMSK0009907, BMSK0002689, BMSK0000286, BMSK0012340 and BMSK00083629 involved in growth and development signaling pathways with differential expression. 【Conclusion】 The differential expression of the critical genes in growth and development signaling pathways of sc and TG disturbs the key physiological processes like energy metabolism, organogenesis and cell growth, proliferation and apoptosis, thereby affecting the body development of the small cocoon mutant sc. These findings contribute to understanding the molecular mechanisms underlying the formation of the sc mutant and offer valuable experimental data for further exploration into the regulation of B. mori body size.

As the most diverse group of animals on earth, insects are closely related to human production and activities, making entomological research both theoretically significant and practically valuable. In the past decade, the rapid development of novel methods and technologies has greatly promoted the research progress of entomological research. In this article, we provided a comprehensive overview of the applications of emerging methods and technologies in such fields as entomological morphological identification, molecular mechanism and pest management, focusing on the main contents of this special issue from seven aspects: Micro-computed tomography, RNA interference, gene editing, artificial intelligence-driven intelligent recognition, nanotechnology, regulation of insect-microorganism symbiotes, and olfactory behavior regulation. We also proposed the challenges faced by the large-scale application and sustainable development of these technologies, and prospected the future development trend.

【Aim】The aim of this study is to investigate the biological function of ABC transporter genes in the development of resistance to indoxacarb in Spodoptera frugiperda, so as to provide a theoretical basis for the comprehensive control of this pest. 【Methods】 Indoxacarb alone and combined with ABC transporter inhibitor verapamil hydrochloride were used to treat the 3rd instar larvae of the indoxacarb-resistant population DC-22 and the indoxacarb-susceptible strain WH of S. frugiperda by the topical application method, and the median lethal concentration (LC₅₀) and the synergistic ratio of verapamil hydrochloride to indoxacarb were calculated at 24 h after treatment. The expression levels of seven ABC transporter genes (SfABCG20, SfABCC2, SfABCF4, SfABCA1, SfABCA5, SfABCG23 and SfABCG9) in the 3rd instar larvae of the indoxacarb-susceptible strain WH and four indoxacarb-resistant populations， including DC-22, CX-22, MY-22 and RH-22, were examined. The highly expressed ABC transporter gene SfABCG23 in response to indoxacarb was silenced through RNAi by injecting dsSfABCG23 into the 3rd instar larvae of DC-22 and WH. The expression level of SfABCG23 was detected by RT-qPCR at 48 h after RNAi, and the mortality was detected at 24 h after exposure to LC₃₀of indoxacarb following RNAi.【Results】Verapamil hydrochloride significantly increased the susceptibility of the indoxacarb-resistant population DC-22 to indoxacarb, with the synergistic ratio of 1.73. The expression levels of SfABCG23 in the 3rd instar larvae of the indoxacarb-resistant populations DC-22 and CX-22 were up-regulated by 2.56- and 4.05-fold, respectively, as compared with that in the indoxacarb-susceptible strain WH, and the expression level of SfABCG23 was significantly positively correlated with the resistance ratio, with the correlation coefficient of 0.941. After dsSfABCG23 injection, the gene silencing efficiency was 65.04% and 39.55%, respectively, in the indoxacarb-resistant population DC-22 and the indoxacarb-susceptible strain WH, and compared with the dsGFP-injected control group, the dsSfABCG23 injection increased the mortality of the 3rd instar larvae of the indoxacarb-resistant population DC-22 and the indoxacarb-susceptible strain WH, by 30.55% and 25.00%, respectively, at 24 h after exposure to indoxacarb. 【Conclusion】 The results of this study suggest that ABC transporter genes play an important role in regulating the development of resistance in the indoxacarb-resistant population of S. frugiperda, and the overexpression of SfABCG23 may play an important role in the development of resistance to indoxacarb in S. frugiperda.

 Pollinators (including bees, butterflies, beetles, flies, moths, etc.) play an irreplaceable and important role in ecosystems, and they directly affect plant reproduction and ecological balance. With the rapid growth of global population and social development, serious problems such as ecological damage and environmental pollution have occurred and exacerbated challenges for pollinators, such as habitat loss and the use of chemical pesticides, synergistic effects of climate change and pathogen transmission, which have many negative impacts on the stability of ecosystems. Therefore, strengthening research on pollinators and exploring their physiological, morphological, behavioural and ecological characteristics as well as their coevolutionary relationship with plants not only contribute to an indepth understanding of the functional mechanisms of biodiversity and ecosystems, but also provide a fundamental scientific basis for the conservation and use of pollinator resources. This special issue of pollinators presented some latest domestic research progress of pollinators, which may promote exchanges and cooperation in the field of pollinators research and advance the development of the discipline in this field, so as to provide a scientific basis for the construction of China’s ecological civilization and the sustainable development of the environment.

【Aim】 Previous study found that the overexpression of CYP6AY3v2 and CYP439A1v3 in deltamethrin-resistant strain JH-del of Laodelphax striatellus is the main mechanism of deltamethrin resistance of L. striatellus. The aim of this study is to clarify the mechanism of up-regulated expression of CYP6AY3v2 and CYP439A1v3 in L. striatellus and to reveal the regulatory signal pathways. 【Methods】 The expression levels of long wavelength-sensitive opsin (LOW) gene LWO of the G proteincoupled receptor (GPCR) family A in the 4th instar nymphs of the deltamethrin-resistant strain JHdel and the sensitive strain JHS of L. striatellus were detected by quantitative PCR. RNAi and Bupivacaine HCL were used to interfere with LWO/AC/cAMP/PKA signal pathway genes LWO, AC-2, AC-3, PKA-1, PKA-2 and PKA-3 of the 3rd instar nymphs of L. striatellus strain JH-del, and bioassay was used to detect the change in the sensitivity of L. striatellus to deltamethrin so as to verify that LWO-activated downstream AC/cAMP/PKA/CYP450s signal pathway genes to mediate deltamethrin resistance of L. striatellus by increasing its own expression level. Transgenic Drosophila combined with GAL4/UAS system and insect baculovirus expression system were used to heterogeneously express the L. striatellus LWOi n the 3-day-old female adults of Drosophila melanogaster and Sf9 cells of Spodoptera frugiperda to verify the function of LWO. 【Results】 The relative expression level of LWO  in the deltamethrin-resistant L. striatellus strain JH-del was 1.54-fold as high as that in the sensitive strain JHS. When any node of the LWO/AC/cAMP/PKA signal pathway in the 3rd instar nymph of L. striatellus strain JH-del was interfered by feeding dsRNAs of target genes, the expression levels of CYP6AY3v2 and CYP439A1v3 that metabolize deltamethrin downstream of this signal pathway were significantly decreased, and the sensitivity of the 3rd instar nymphs of strain JH-del of L. striatellus was restored as compared with that in the control group (fed with ds GFP). After heterologous expression of LWO in D. melanogaster and Sf9 cells, the resistance of D. melanogaster and Sf9 cells to deltamethrin increased significantly, and the increase of deltamethrin resistance was also mediated by LWO/AC/cAMP/PKA/CYP450s signal pathway of L. striatellus. 【Conclusion】 LWO receptor activates downstream AC/cAMP/PKA/CYP450s signal pathway by increasing its own expression level, which mediates deltamethrin resistance of L. striatellus. The results provide a theoretical basis for resistance management of L. striatellus and screening of new insecticide targets.

The red imported fire ant, Solenopsis invicta, is an invasive pest that poses a serious threat to agricultural and forestry industries, people’s health, public facilities and biodiversity. Its extreme aggressiveness and strong environmental adaptability make the control of this species a significant challenge. As a soil-dwelling social insect, S. invicta relies primarily on its developed chemical communication system. S. invicta uses a variety of semiochemicals as carriers to efficiently transmit information with other organisms inside and outside nests, thereby coordinating the behavior of ant colonies and completing important life activities. Therefore, understanding the characteristics of the chemical communication of S. invicta may help to timely control the spread of this species. In this article, we focused on the chemical communication system of S. invicta, summarizing the regulatory roles of various important semiochemicals inside and outside the colonies of S. invicta in the social behaviors of ant colonies, including the trail pheromone and alarm pheromone of S. invicta during foraging and dealing with dangers, cuticular hydrocarbons (CHCs)-based individual recognition inside and outside nests and necrophoric behavior, the ability of interspecies eavesdropping to other organisms and the queen pheromone for regulating the development direction of larval ants. We also reviewed and summerized the contemporary applications and problems of S. invicta semiochemicals, with the aim of providing a theoretical reference for its green prevention and control.

【Aim】 This study aims to enrich the basic information of 14-3-3ζ gene of Apis cerana cerana, so as to provide a reference and basis for its further functional study. 【Methods】 The coding sequence (CDS) of 14-3-3ζ gene was amplified by RT-PCR, followed by TA cloning and Sanger sequencing. The physicochemical properties and molecular features of 14-3-3ζ were predicted using the relevant software, and the phylogenetic analysis of 14-3-3ζ was performed. RT-qPCR was used to detect the expression levels of 14-3-3ζ gene in different developmental stages (egg, larva, pre-pupa, pupa and adult), and different tissues (antennae, midgut, fat body, hypopharyngeal gland, brain, cuticle and venom gland) of the newly emerged adult workers of Ap. cerana cerana, as well as in the guts of the 4-, 5- and 6-day-old larvae of Ap. cerana cerana after inoculating the 3-day-old larval workers with Ascosphaera apis.【Results】 The CDS of 14-3-3ζ gene of Ap. cerana cerana was successfully cloned, including 744 nucleotides and encoding 247 amino acids. 14-3-3ζ of Ap. cerana cerana had the molecular weight of about 28.0 kD, included 26 phosphorylation sites, four structural domains and one conserved motif, but had no transmembrane domains and signal peptides. The 14-3-3ζ proteins of Ap. cerana cerana, Ap. mellifera, Ap. laboriosa, Ap. florea, Ceratina calcarata, Bombus pyrosoma, B. terrestris, Megachile rotundata, Osmia lignaria and Habropoda laboriosa all contained four identical conserved motifs and one same structural domain (14-3-3_1). The 14-3-3ζ proteins of Ap. cerana cerana and Ap. mellifera clustered into a single clade on the phylogenetic tree. The expression level of 14-3-3ζ gene in Ap. cerana cerana eggs was significantly higher than those in the 3-day-old larvae, 1-day-old prepupae, 2-day-old prepupae and 4-day-old pupae. The differences in the expression level of 14-3-3ζ gene in various day-old adult workers of Ap. cerana cerana were non-significant. The expression level of 14-3-3ζ gene in the venom gland of the newly emerged adult workers of Ap. cerana cerana was the highest, significantly higher than those in the antennae, midgut, hypopharyngeal gland, brain, cuticle and fat body. Following inoculation of the 3-day-old larval workers of Ap. cerana cerana with As. apis, the expression levels of 14-3-3ζ gene in the 4-, 5- and 6-day-old larval worker guts of Ap. cerana cerana were significantly down-regulated as compared with those in the control group.【Conclusion】 Ap. cerana cerana 14-3-3ζ gene is specifically and highly expressed in the venom gland and egg of worker, and the expression of 14-3-3ζ gene in the larval guts is activated in the process of As. apis infection. 14-3-3ζ is a putative hydrophilic, non-transmembrane and intracellular protein, and highly conserved in Ap. cerana cerana and the above other ten bee species. There is the closest genetic relationship between 14-3-3ζ of Ap. cerana cerana and Ap. mellifera.
Key words: Apis cerana cerana; 14-3-3; molecular features; expression pattern; Ascospaera apis

【Aim】 The objective of this study is to investigate the oviposition deterrent and antifeedant effects of plant essential oils (EOs) on a major invasive pest, the fall armyworm, Spodoptera frugiperda, and provide a new method for the green control of this pest. 【Methods】 S. frugiperda collected from a maize field in Zhanjiang, Guangdong Province, South China and reared indoors for several generations was used. In the laboratory, the oviposition deterrent activities of EOs from 21 plants (Perilla frutescens, Cupressus funebris, Acorus calamus, Artemisia argyi, Capsicum annuum, Myristica fragrans, Zingiber officinale, Piper nigrum, Allium sativum, Cedrus deodara, Cinnamomum cassia, Mentha canadensis, Mentha spicata, Litsea cubeba, Melia azedarach, Citrus limon, Camellia sinensis, Cymbopogon citratus, Eucalyptus globules, Cinnamomum camphora and Plectranthus hadiensis) against S. frugiperda adults were investigated using the behavior selection method, while the antifeedant activities of these EOs against the 2nd instar larvae of S. frugiperda were evaluated using the leaf dish feeding method. 【Results】 At the concentration of 2.5 mL/L, Capsicum annuum EO and Melia azedarach EO had the best oviposition deterrent effects on S. frugiperda adults, with the deterrent rates of 89.13% and 88.83%, respectively. At the concentration of 5 mL/L, Capsicum annuum EO showed the best oviposition deterrent effect on S. frugiperda adults, with the deterrent rate of 100.00%. At the concentration of 10 mL/L, the EOs from Perilla frutescens, Cupressus funebris, Capsicum annuum, Myristica fragrans, Piper nigrum, Allium sativum, Cedrus deodara and Citrus limon showed obvious oviposition deterrent effects on S. frugiperda adults. Piper nigrum EO at the concentration of 2.5 mL/L had the best non-selective and selective antifeedant effects on the 2nd instar larvae of S. frugiperda, with the antifeedant rates of 98.67% and 97.37%, respectively. At the concentrations of 5 and 10 mL/L, Piper nigrum EO also exhibited the best antifeedant effects on the 2nd instar larvae of S. frugiperda, both with the antifeedant rate of 100.00%. 【Conclusion】 At relatively low concentrations, Cayenne pepper EO and Melia azedarach EO showed highly effectiveness in deterring oviposition of S. frugiperda adults, and Piper nigrum EO showed excellent antifeedant activity against the 2nd instar larvae of S. frugiperda. These plant EOs demonstrated promising application potential in the green control of S. frugiperda.

【Aim】 The objective of this study is to elucidate the regulatory function of piR-ame-1186994 of Apis mellifera ligustica, so as to offer a scientific basis for further investigation of the underlying regulatory mechanism of piR-ame-1186994. 【Methods】 The expression and sequence authenticity of piR-ame-1186994 in the 6-day-old adult worker’s midgut, 12-day-old adult drone’s testis and 7-day-old adult queen’s ovary of A. m. ligustica were verified by Stem-loop RT-PCR and Sanger sequencing, respectively. Relevant software was utilized to predict the target mRNAs of piR-ame-1186994 followed by GO and KEGG database annotation. Regulatory networks related to developmental signaling pathways, energy metabolism pathways and cellular and humoral immune pathways were further constructed. Newly emerged adult workers were fed with mimic and mimic-NC (negative control) of piR-ame-1186994, followed by the detection of the relative expression levels of piR-ame-1186994 and its key target genes (YAP1 and PLD2) in the midguts of adult workers using RT-qPCR. 【Results】 The specific fragment of piR-ame-1186994 was amplified from the 6-day-old adult worker’s midgut, 12-day-old adult drone’s testis and 7-day-old adult queen’s ovary of A. m. ligustica. piR-ame-1186994 targeted 1 097 mRNAs, which could be annotated to 30 GO terms involved in metabolic process, binding, cell, etc., and 182 KEGG pathways including Wnt signaling pathway, endocytosis and oxytocin signaling pathway. Thirty-six and 16 target mRNAs were respectively involved in five developmental-related signaling pathways (mTOR, Wnt, Hippo, AMPK and Notch signaling pathways) and four pathways related to energy metabolism (amino sugar and nucleotide sugar metabolism, fructose and mannose metabolism, glycolysis/gluconeogenesis, and pentose phosphate pathway), respectively. Additionally, 29 and eight target mRNAs were engaged in four cellular immune pathways (lysosome, endocytosis, phagosome and ubiquitin-mediated protein degradation) and three humoral immune pathways (PI3K-Akt, MAPK and FoxO signaling pathways), respectively. In the mimic-piR group, the expression level of piR-ame-1186994 was significantly up-regulated in the 1-, 3- and 5-day-old workers’ midguts and up-regulated extremely significantly in the 2- and 4-day-old workers’ midguts, the expression level of the target gene YAP1 was extremely significantly down-regulated in the 1-, 3-, 4- and 5-day-old workers’ midguts and significantly down-regulated in the 2-day-old worker’s midgut, and the expression level of target gene PLD2 was significantly down-regulated in the 2-, 3- and 5-day-old workers’ midguts and downregulated extremely significantly in the 4-day-old worker’s midguts as compared with those in the mimic-NC group. 【Conclusion】 piR-ame-1186994 exists and expresses in the worker’s midgut, drone’s testes and queen’s ovary of A. m. ligustica. piR-ame-1186994 potentially modulates the development and immunity of worker’s midgut through targeting and negatively regulating the expression of YAP1 and PLD2.

【Aim】The aim of this study is to clarify the level of the field-evolved resistance of Tuta absoluta to spinetoram and its potential resistance risk, in order to provide a theoretical basis for the rational use of spinetoram to control T. absoluta and slowing development of its resistance to spinetoram. 【Methods】 The leaf-dipping method was used to determine the resistance levels of 18 field populations of T. absoluta collected from five provinces (municipalities or autonomous regions) in northern China to spinetoram. To assess the resistance risk of T. absoluta to spinetoram, 10-generation consecutive selections with spinetoram were carried out in the spinetoram-susceptible strain of T. absoluta via the leaf-dipping method. After that, the realized heritability (h²) of resistance was calculated using Tabashnik’s method for threhold trait agalysis, and the resistance development rates under different selection pressures were predicted based on the data of selection. 【Results】 Among the 18 field populations of T. absoluta, three populations including the populations from Miyun and Huairou in Beijing, and Baotou in Inner Mongolia, exhibited low-level resistance to spinetoram, with the resistance ratios of 6.7, 6.0 and 7.1, respectively. On the other hand, the other 15 populations of T. absoluta were susceptible to spinetoram. After 10-generation consecutive selections with spinetoram, T. absoluta developed 8.9-fold resistance to spinetoram, with the h2 of 0.1973. It was predicted that under different selection pressures (mortality=50%, 60%, 70%, 80% and 90%), T. absoluta needed 11.56, 9.50, 7.92, 6.60 and 5.23 generations, respectively, to develop 10-fold resistance to spinetoram, and 23.12, 18.99, 1583, 13.19 and 10.47 generations, respectively, to develop 100-fold resistance to spinetoram. 【Conclusion】 Due to the risk of T. absoluta developing resistance to spinetoram, it is essential to strengthen insecticide management in the field and emphasize the rotation with alternative types of insecticides to prolong the lifecycle of this insecticide.

 One of the hot topics in entomology today is the symbiotic microorganism-host interactions in insects. Symbiotic microorganisms in insects can not only provide nutrients for the growth and development of the hosts, but also synthesize many active substances that regulate the ecological adaptability, stress resistance, diversity formation, reproduction, and mating behavior of hosts. Despite of their widespread use, microbial insecticides have led to varying degrees of resistance in pests due to the toxicity of their metabolites and their long-term application in the field. The development of this resistance is closely related to the symbiotic microorganisms in pests. In this article, we reviewed the role of insect symbiotic microorganisms in the development of host resistance to adversity stresses, with focuses on the role of insect symbiotic microorganisms in assisting hosts to resist infestation by different species of biocontrol fungi/bacteria, such as Beauveria, Metarhizium, Pandora neoaphidis and Bacillus thuringiensis. In addition, we deeply clarified the defense mechanisms of symbiotic microorganisms against exogenous pathogen infestation. The present studies showed that the symbiotic microorganisms against exogenous pathogens are mainly distributed in the epidermis, antennal glands and gut of insects, and the symbiotic microorganisms such as Pantoea, Pseudomonas, Wolbachia, Citrobacter freundii and Arsenophonus are more prominent in assisting the hosts to fight the pathogen infestation, having a protective effect on various insect hosts. In addition, these symbiotic microorganisms improve the resistance of insects to pathogens mainly through three pathways: Competition for nutrients with exogenous microorganisms, secretion of antimicrobial substances and modulation of the immune system. This article provides new ideas for a comprehensive elucidation of the mutualistic interactions among pathogenic microorganisms, insects and symbiotic microorganisms, and can also serve as a valuable reference for the development of pest biological control strategies based on the regulation of symbiotic relationships.

【Aim】 Picromerus lewisi is a significant predatory natural enemy insect distributed in multiple countries of Asia, such as China, Korea and Japan, primarily used for controlling lepidopteran pests. Venom plays a crucial role in causing rapid paralysis and death of preys during hunting. The aim of this study is to understand the transcriptomic characteristics of the venom glands of P. lewisi, explore the diversity of toxins in P. lewisi, and establish a foundation for further research on the composition and function of the venom in P. lewisi.【Methods】Transcriptome sequencing was conducted on the venom glands of adults and the 5th instar nymphs of P. lewisi collected from Qianxinan Prefecture, Guizhou Province using the high-throughput Illumina NovaSeq 6000 platform. The resulting data were annotated using the NR, NT, Pfam, KOG/COG, Swiss-Prot, KEGG and GO databases. Gene expression in the venom gland samples of P. lewisi was assessed using the FPKM method, and DESeq was employed for the differential expression analysis of venom gland transcriptomes between adult and the 5th instar nymph. The differentially expressed genes (DEGs) between the adult and the 5th instar nymphal venom gland transcriptomes were screened using the criteria of |log₂(Fold change)|>1 and P<0.05, followed by GO functional enrichment analysis and KEGG pathway enrichment analysis of the identified DEGs. The 33 215 transcripts obtained from the sequenced venom gland transcriptomes of adults and the 5th instar nymphs of P. lewisi were subjected to BLAST comparisons in the UniProt database.【Results】Transcriptome sequencing of the venom glands of adults and the 5th instar nymphs of P. lewisi assembled to 22 242 unigenes with an average length of 949 bp. A total of 15 364 unigenes were annotated to the NR, NT, Pfam, Swiss-Prot, GO, KOG/COG and KEGG databases, corresponding to 10 closely related species including three species of true bugs and two species of spiders. A total of 344 DEGs were screened between the venom gland transcriptomes of adults and the 5th instar nymphs of P. lewisi, with 218 genes up-regulated and 126 genes down-regulated. A total of 443 sequences encoding 33 distinct types of toxin-related proteins were identified.【Conclusion】The transcriptome data from the venom glands of both the 5th instar nymphs and adults of P. lewisi were sequenced and obtained in this study. Differential proteins between the venom gland transcriptomes of adults and the 5th instar nymphs were screened, and sequences associated with toxin proteins were identified. This research lays a theoretical foundation for the identification of components in the venom of P. lewisi and the investigation of their biological functions.

【Aim】 Through laboratory insecticidal effect determination and field control efficacy evaluation, the insecticides with high control efficacy against Tuta absoluta were screened to satisfy the demand for emergency control of this pest in production.【Methods】 T. absoluta larvae collected from tomato plants in the field were reared in the laboratory for more than 45 generations, the effects of 10 commonly used insecticides of seven categories including 5% emamectin benzoate water dispersible granule (WG), 60 g/L spinetoram suspension concentrate (SC) and 5% spinosad SC (antibiotics), 200 g/L chlorantraniliprole SC (bisamide), 150 g/L indoxacarb emulsifiable concentrate (EC)(oxadiazine), 10% chlorfenapyr SC (pyrroles), 240 g/L methoxyfenozide SC (hormone), 2.5% rotenone EC (botanical source), and 8 000 IU/μL Bacillus thuringiensis SC and 30 billion spores/g Beauveria bassiana wettable powder (WP)(microbial source) on the hatching rates of T. absoluta eggs and the  mortality rates of the 2nd instar larvae were determined by indoor egg-dipping method and leaf-dipping method, respectively. In July 2023, five insecticide formulations with strong insecticidal effects on T. absoluta in laboratory bioassay were sprayed to open field tomatoes in Xinjiang, Northwest China to evaluate their field control efficacy against T. absoluta. 【Results】 Laboratory bioassay results showed that the 10 pesticides had different effects on the hatching of T. absoluta eggs, the microbial insecticides 8 000 IU/μL B. thuringiensis SC and 30 billion spores/g B. bassiana WP and the botanical insecticide 2.5% rotenone EC had no significant effect on the hatching of eggs at 7 d after treatment, while the chemical insecticides 240 g/L methoxyfenozide SC, 60 g/L spinetoram SC and 5% emamectin benzoate WG exhibited significant inhibitory effects on the hatching of eggs in 5 d. The 10 pesticides had different lethal effects on the 2nd instar larvae of T. absoluta. Among the chemical pesticides, 60 g/L spinetoram SC showed the highest insecticidal activity against the 2nd instar larvae, causing 100.00% mortality rate at 1-4 d post treatment, and 10% chlorfenapyr SC and 150 g/L indoxacarb EC causing 100.00% mortality rate at 3 and 4 d post treatment, while the botanical insecticide 2.5% rotenone  EC  and the microbial insecticide  30 billion spores/g B. bassiana WP had lower lethal effects on the 2nd instar larvae during the 4-d treatment. Field experiment results revealed that the control efficacy of the tested five insecticide formulations against T. absoluta was most obvious at 7 d after application. The control efficacy of 60 g/L spinetoram SC, 200 g/L chlorantraniliprole SC and 10% chlorfenapyr SC against T. absoluta was ranked the top three, being 91.14%, 90.29% and 88.67%, respectively.【Conclusion】 Through laboratory bioassay and field control efficacy evaluation, it was found that 60 g/L spinetoram SC, 200 g/L chlorantraniliprole SC and 10% chlorfenapyr SC at their recommended dosages can be used for chemical control of T. absoluta in tomato production, which can provide guidance for the formulation of comprehensive control plans for T. absoluta and the selection of field control agents.

【Aim】 To reveal the functions of the cytochrome P450 (CYP450）genes, HcCYP4S47 and HcCYP332A29, in Hyphantria cunea in response to chlorantraniliprole stress.【Methods】The diets containing LC₃₀ (0.06 mg/L) of chlorantraniliprole were fed to the 3rd instar larvae of the laboratory population, northern population (Tieling population from Liaoning), and southern population (Dawu population from Xiaogan, Hubei) of H. cunea via mixing the pesticide into the diets, and the surviving larvae were collected at 6, 12, 24 and 48 h after feeding treatment, respectively. The CYP450 activity in the 3rd instar larvae of H. cunea was determined. The expression levels of HcCYP4S47 and HcCYP332A29 in the 3rd instar larvae of the three geographical populations after exposure to 0.06 mg/L of chlorantraniliprole were analyzed using RT-qPCR. Additionally, HcCYP4S47 and HcCYP332A29 in the 3rd instar larvae of the three geographical populations were silenced by RNAi technology, and the expression levels of target genes were detected by RT-qPCR after dsRNA injection. The diets containing 0.06 mg/L of chlorantraniliprole were fed to the gene-silenced 3rd instar larvae of the three geographical populations, and the survival rates of H. cunea larvae were recorded at 12, 24, 36, 48, 60 and 72 h after feeding.【Results】 After exposure to 0.06 mg/L of chlorantraniliprole, the CYP450 activities in the 3rd instar larvae of the northern and southern populations of H. cunea were higher than those in the laboratory population at four treatment time points (6, 12, 24 and 48 h). Specifically, the CYP450 activity in the 3rd instar larvae of the northern population in the chlorantraniliprole treatment group exhibited the highest levels at 24 and 48 h after treatment, while that in the 3rd instar larvae of the southern population in the chlorantraniliprole treatment group peaked at 12 and 24 h after treatment. Phylogenetic analysis indicated that HcCYP4S47 and HcCYP332A29 belong to the CYP4 and CYP3 subfamilies, respectively. The expression levels of HcCYP4S47 and HcCYP332A29 were significantly higher in the 3rd instar larvae of the northern and southern populations than those in the 3rd instar larvae of the laboratory population. After exposure to 0.06 mg/L of chlorantraniliprole, the expression levels of HcCYP4S47 and HcCYP332A29 were significantly up-regulated in the 3rd instar larvae of the laboratory population as compared to those in the control group, peaking at 12 h post treatment. The expression levels of HcCYP4S47 in the 3rd instar larvae of the southern and northern populations were significantly down-regulated at 6, 12 and 48 h after chlorantraniliprole treatment, that in the northern population was significantly up-regulated and that in the southern population showed no significant change at 24 h after chlorantraniliprole treatment, as compared to that in the control group. The expression level of HcCYP332A29 in the 3rd instar larvae of the northern population in the chlorantraniliprole treatment group was significantly decreased at 6 and 12 h, but significantly up-regulated at 48 h, as compared to that in the control group. The expression level of HcCYP332A29 in the 3rd instar larvae was significantly decreased at 6 and 12 h after chlorantraniliprole treatment but significantly up-regulated at 48 h after chlorantraniliprole treatment as compared to that in the control group. In the 3rd instar larvae of the southern population, the expression level of HcCYP332A29 was significantly down-regulated at 6 h after chlorantraniliprole treatment, followed by a significant increase at 12 and 24 h. Silencing HcCYP332A29 and HcCYP4S47 increased the susceptibility of the 3rd instar larvae of H. cunea to chlorantraniliprole. 【Conclusion】 HcCYP332A29 and HcCYP4S47 play crucial roles in the response of H. cunea to chlorantraniliprole stress.

【Aim】This study aims to elucidate the circadian rhythms of the behavioral activities of Phyllotreta striolata adults and the staying positions at different time under different light intensities， so as to provide a basis for indoor breeding, behavioral research, and the development of innovative control technologies. 【Methods】The circadian rhythms of movement, mating, feeding and resting of P. striolata adults were observed and recorded under the artificial light-dark conditions (light intensity: 5 000 lx; photoperiod: 16L∶8D), the time allocation characteristics and staying positions of their specific behaviors were analyzed, and the differences in their behavior activities under three light intensities (500, 5 000 and 10 000 lx) were compared. 【Results】The most prevalent behavioral activity observed in P. striolata adults during day and night was resting, which peaked from 22:00 to 6:00. Feeding of P. striolata adults was only observed during daylight hours, from 8:00 to 18:00, with a peak at 8:00. Mating of P. striolata adults occurred exclusively at night, from 0:00 to 2:00. From 6:00 to 18:00, P. striolata adults demonstrated a preference for the backside and heart of leaves, as well as the sides of insect rearing cages, with the proportions of frequency staying on these positions significantly higher than those at night. The proportion of frequency of adults remaining in the soil or on the leaf surface at night was significantly higher than that at daytime. Light intensity was shown to significantly influence the behavioral activities of P. striolata adults. Under the light intensity of 500 lx, there was a significant reduction in the proportion of frequency of feeding behavior of P. striolata adults. However, when the light intensity increased to 5 000 lx and above, the proportion of frequency of the resting behavior of P. striolata adults was significantly reduced. Under the light intensity of 5 000 lx, feeding behavior of P. striolata adults was most prevalent, and compared to the light intensity of 10 000 lx, the light intensity of 5 000 lx caused a notable decrease in the proportion of frequency of movement behavior of P. striolata adults. Additionally, under the light intensity of 500 lx, the proportion of frequency of P. striolata adults remaining on the backside and heart of leaves was significantly less than those under the other two light intensities, whereas under the light intensity of 5 000 lx, P. striolata adults tended to prefer staying on the surface of leaves. 【Conclusion】The behaviors of P. striolata adults, including movement, feeding, mating and resting, as well as their staying positions, exhibit distinct circadian rhythms. The frequencies of different behaviors and time points of activity peaks differ, and various behavioral activities and staying positions are subject to the effects of light intensity.

【Aim】To explore the effect of Lactobacillus on the transcription level of antimicrobial peptide genes in Bombyx mori. 【Methods】After spraying the suspension (2×10 ⁸ CFU/mL) of Lactobacillus plantarum FLPL028, L. rhamnosus FLRH956 and L. reuteri FLRE589 to the mulberry leaves (20 μL/cm ²) to feed the 1st instar larvae of B. mori, the RNAref transcriptome sequencing of the 5th instar larvae was performed and the mortality rate before cocooning of B. mori after feeding the 5th instar larvae with the mulberry leaves sprayed with the suspension (2×10 ⁶ CFU/mL, 20 μL/cm ²) of Serratia marcescens was calculated. The numbers of viable bacteria of S. marcescens were counted at 4 h after incubation with L. plantarum FLPL028, L. rhamnosus FLRH956 and L. reuteri FLRE589, respectively. The expression levels of immune-related genes including LOC101742127, glv1,glv2, CecA, LOC101739681, CecD, Attacin1, Leb3 and Lzm (antimicrobial peptide genes), LOC692824 (lectin gene), PGRP-S1 and LOC101738493(Toll/Imd signaling pathway-related genes), and Pi3k60, MAPK and Ras2(PI3K and MAPK signaling pathway-related genes) in the 5th instar larvae of B. mori were detected by qPCR. 【Results】After the 1st instar larvae of B. mori were fed with L. plantarum FLPL028, L. rhamnosus FLRH956 and L. reuteri FLRE589, respectively, the transcription levels of most antimicrobial peptide genes, including Moricin, glv4-like and glv2, were significantly decreased in the 5th instar larvae, and that of Moricin decreased the most, as compared with those of the control group. After the 1st instar larvae of B. mori were fed with L. plantarum FLPL028, L. rhamnosus FLRH956 and L. reuteri FLRE589, respectively, the transcription levels of lectin genes such as CTL10, CTL19 and LOC101736606, and Toll/Imd signaling pathway-related genes PGRP-S2, LOC101738325 and LOC101738493 in the 5th instar larvae decreased, and those of PI3K and MAPK signaling pathway-related genes Pi3k60 and MAPK were increased by about 2.4- and 2.1-fold, respectively, as compared with those of the control group. However, the above three species of Lactobacillus had antagonistic effects on S. marcescens, and reduced the mortality rate of B. mori in the model group (only fed with S. marcescens) from 83% to less than 35%, among them L. reuteri FLRE589 had the best antagonistic effect on S. marcescens, causing only 18.1% mortality rate of the 5th instar larvae of B. mori. The basic change trends of the expression levels of LOC101742127, glv1, glv2, CecA, LOC101739681, CecD, Attacin1, Leb3, Lzm, LOC692824, LOC101738493, PGRP-S1, Pi3k60, MAPK and Ras2 were consistent with those of RNAref transcriptome sequencing results. The supernatant of the fermentation of these three species of Lactobacillus could effectively kill S. marcescens and reduce the number of viable bacteria of S. marcescens.【Conclusion】Lactobacilli inhibits the expression of antimicrobial peptide genes and Toll/Imd immune pathway-related genes in B. mori, reduces the innate immune response of B. mori, but is conducive to the harmony between Lactobacilli and B. mori. In addition, Lactobacilli can also improve the acquired immunity of B. mori by activating the PI3K and MAPK signaling pathways. This finding will help to understand the immune system of B. mori more comprehensively and provide a new strategy for the prevention and control of diseases in B. mori industry.

 Reactive oxygen species (ROS) is a general term for a class of oxygen-containing free radicals formed due to incomplete oxidation of oxygen molecules, or peroxides that are easy to form oxygen free radicals. When insects are invaded by pathogens, the ROS defense system mediated by dual oxidase (DUOX) will respond quickly to produce a large amount of ROS to resist the invasion of pathogenic bacteria, and then play a role in regulating the immune defense process of insects. However, high level of ROS can damage the biological macromolecules such as proteins, DNA and lipids in cells, causing damage to insect cells and affecting the normal development of insects. In order to avoid damage from excessive oxidative stress, insects have formed a complete antioxidant defense system mainly composed of antioxidant enzymes and small molecule antioxidants to prevent excessive damage from occurring. It is interesting that changes in ROS levels in cells can play completely different roles in regulating insect lifespan: for certain insects the accumulation of a large amount of ROS could lead to a shortened lifespan, while for some other insects the presence of high physiological levels of ROS could also induce diapause and prolong their lifespan. Studies on the regulatory mechanisms of ROS in insect lifespan have achieved a lot of progress in recent years. Therefore, in this article, we comprehensively reviewed the sources and influencing factors of insect ROS, the defense mechanisms mediated by ROS, and for the first time made a summary and outlook on the specific roles of ROS in regulating insect lifespan, so as to provide a reference for subsequent research on ROS-related topics.

 Sensory neuron membrane proteins (SNMPs) are a class of membrane proteins uniquely to insects, typically possessing two characteristic transmembrane domains, and are also an important member of the CD36 family. Currently, insect SNMPs have been classified into five subfamily types, namely SNMP1, SNMP2, SNMP3, SNMP4 and SNMP5, each exhibiting distinct expression patterns across different insect species. SNMP1 subfamily genes, which are expressed in the antennae and olfactory sensory neurons (OSNs) of insects, have been extensively studied and confirmed to play a significant role in pheromone detection across various insect species. The widespread expression pattern of SNMP2 subfamily genes also suggests their role in olfaction and gustation. SNMP3 subfamily genes, which are specifically expressed in the midgut of lepidopteran insects, may function in digestion and immunity in insects. SNMP4 and SNMP5 subfamily genes which are unique to coleopteran insects, may be involved in a broader range of life activities in insects. Despite of the crucial role of SNMPs in insect olfactory system, the mechanism of action of SNMP1 with other receptor proteins has remained unclear. Additionally, research on the functions and mechanisms of action of the members of the other SNMP subfamilies especially in non-model insects remains limited. In this article, we summarized and discussed the diverse expression patterns of SNMP subfamily genes, various physiological and biological functions of SNMPs that may play in insect physiological activities, and the application of molecular biology, molecular genetics, heterologous cell expression systems, yeast two-hybrid, and other methods and technologies in the current functional study of insect SNMPs, providing references for future research on the function of insect SNMPs. Lastly, we put forward the following prospects of research focuses: (1) In-depth research on the relationship between SNMP1 and insect pheromones will contribute to the development of novel pheromone-based lures for pest control applications; (2) In the future, the use of artificial intelligence and protein structure analysis will aid in uncovering the mechanisms by which SNMPs interact with other receptor proteins to participate in odor recognition; and (3) Further research on other subfamilies of insect SNMPs in the realms of taste, digestion, immunity, and survival and development will not only enhance our understanding of the fundamental biological characteristics of insects but may also provide new strategies and methods for pest management.

-【Aim】Tuta absoluta is a newly invaded devastating pest on tomatoes in China, and poses a significant threat to tomato production. Olfactory behavior manipulation technique is an important component of the green control techniques of T. absoluta. By exploring the effects of the components of floral scents, tomato plant volatiles and volatiles from traditional food baits (fermented sugar water and sugar vinegar solution) on the behavior of T. absoluta, this study aims to provide a reference for the development of olfactory behavior manipulation technique for this pest. 【Methods】First, the electroantennogram (EAG) response experiments were carried out to assay the EAG responses of the female and male adults of T. absoluta to 24 compounds including nine compounds of floral scents ［linalool, methyl o-anisate, ethyl hexanoate, cis-jasmone, (-)-limonene, phenylacetaldehyde, β-myrcene, methyl salicylate and ethyl benzoate］, four components of tomato plant volatiles (octyl acetate, catechol, resorcinol and hydroquinone), 11 volatile compounds of from traditional food baits (2-ethyltoluene, decanal, ethyl decanoate, 3-furaldehyde, 1, 2-diethylbenzene, ethyl heptanoate, ethyl octanoate, n-propylbenzene, ethyl nonanoate, benzaldehyde and 1, 4-diethylbenzene) at the doses of 1, 10， 100 and 1 000 μg. Then, the olfactory behavior responses were determined with Y-tube olfactometer to test the attractiveness of 12 compounds screened out by the above experiments with high EAG responses at the doses of 1, 10, 100 and 1 000 μg to the female and male adults of T. absoluta. Finally, the oviposition selection behavior was determined with cage experiments to test the oviposition attraction effects of six effective attractants screened out by the above tests on the female adults of T. absoluta. 【Results】 Twelve volatile compounds, including linalool（10, 100 and 1 000 μg）, decanal（1, 10, 100 and 1 000 μg）, methyl o-anisate（10, 100 and 1 000 μg）, octyl acetate（10, 100 and 1 000 μg）, 3-furaldehyde（1, 10, 100 and 1 000 μg）, ethyl heptanoate（10, 100 and 1 000 μg）, phenylacetaldehyde（10, 100 and 1 000 μg）, resorcinol（1, 10, 100 and 1 000 μg）, methyl salicylate（1, 10, 100 and 1 000 μg）, hydroquinone（1, 10, 100 and 1 000 μg）, ethyl benzoate（1, 10, 100 and 1 000 μg） and 1,4-diethylbenzene（100 and 1 000 μg） elicited high EAG responses in both female and male adults of T. absoluta. Results from the olfactometer bioassay indicated that six compounds including decanal(10 μg), ethyl heptanoate(10 and 1 000 μg), octyl acetate(100 μg), resorcinol(10 μg), methyl salicylate(1 000 μg), and ethyl benzoate(100 and 1 000 μg) had attraction effects on T. absoluta adults, with decanal(10 μg), ethyl heptanoate(10 and 1 000 μg), resorcinol(10 and 1 000 μg) and ethyl benzoate(100 and 1 000 μg) showing significant attraction to female or male adults, and decanal(10 μg) and ethyl benzoate(100 μg) exhibiting bisexual attraction effects at the same dose. Oviposition selection results demonstrated that decanal (10  μg), ethyl heptanoate (100 μg), octyl acetate (1 000 μg), resorcinol (10 μg), methyl salicylate (1 000 μg), and ethyl benzoate (1 000 μg) showed significant oviposition attractiveness to female adults of T. absoluta. 【Conclusion】 Six volatile compounds including decanal, ethyl heptanoate, octyl acetate, resorcinol, methyl salicylate and ethyl benzoate show significant attractive and oviposition stimulant activities to T. absoluta adults, and decanal and ethyl benzoate have the potential to be developed as bisexual attractants. These results provide references for the development of green control techniques for T. absoluta.

【Aim】 This study aims to systematically identify and analyze the genes related to peptidoglycan recognition proteins (PGRPs) and their splice variants in Apis mellifera, to explore the physicochemical properties and molecular characteristics of PGRP gene splice variants-encoding proteins, and to determine the expression profile of PGRP gene splice variants in response of adult workers of A. mellifera to Nosema ceranae infection, so as to offer the reference and basis for functional study on splice variants of PGRP genes of A. mellifera. 【Methods】Based on the obtained nanopore sequencing data from the midguts of the 8- and 11-day-old adult workers of A. mellifera, the previously identified all full-length transcripts were aligned to the Nr and KEGG databases by using the Blast tool to screen PGRP genes of A. mellifera and their splice variants, and RT-PCR was used to validate the authenticity of the sequences of five splice variants of PGRP genes randomly selected. Gffcompare software was utilized to align the sequences of the identified PGRP genes to the reference genome of A. mellifera, thus optimizing the gene structures. Astalavista software was employed to identify the types of alternative splicing (AS) events in PGRP genes, and AS events were then verified by RT-PCR and Sanger sequencing. Related software was used to predict and analyze the physicochemical properties and molecular characteristics of the proteins encoded by the splice variants of PGRP genes. RT-qPCR was conducted to determine the relative expression levels of PGRP gene splice variants in the midguts of A. mellifera adult workers after inoculation with N. ceranae.【Results】 A total of four PGRP-associated genes (PGRP-3, PGRP-S2, PGRP-LC and PGRP-LB) and their 19 splice variants of A. mellifera were identified. RT-PCR and Sanger sequencing results confirmed the authenticity of expression and sequences of five splice variants (rna14029, ONT.6350.8, ONT.6350.10, rna24089, ONT.6350.7) of PGRP genes. The 5′ and 3′ ends of PGRP-3 (gene10434) were elongated by 8 and 1 055 bp,  respectively, while those of PGRP-S2 (gene10435) were elongated by 27 and 234 bp, respectively. The authenticity of AS events in PGRP-S2 was verified by RT-PCR. The splice variant ONT.6350.2-encoded protein had a molecular formula of C₉₆₆H₁₅₀₂N₂₇₂O₂₇₅S₇, an approximate molecular weight of 21 527.63 D, a theoretical isoelectric point (pI) of 8.94, an average hydrophilicity of -0.119, a signal peptide, a PGRP domain and no transmembrane domain. The protein encoded by the splice variant ONT.6350.6 had a molecular formula of C₈₄₁H₁₃₀₁N₂₄₃O₂₄₄S₅, an approximate molecular weight of 18 860.46 D, a theoretical pI of 9.14, an average hydrophilicity of -0.324, and no transmembrane domain and signal peptide. PGRP-S2 proteins from A. mellifera and A. cerana were clustered into a single clade on the phylogenetic tree. The expression level of the splice variant ONT.6350.2 in the midguts of adult workers inoculated with N. ceranaewas significantly upregulated at 2 and 4 d post inoculation and extremely significantly upregulated at 3 d post inoculation as compared with that in the midguts of A. mellifera adult workers uninoculated with N. ceranae in the control group. Additionally, the splice variant ONT.6350.6 had the same expression pattern as ONT.6350.2. Moreover, both ONT.6350.2 and ONT.6350.6 in the midguts of adult workers inoculated with N. ceranae exhibited an overall increased expression trend at 1－4 d post inoculation as compared with those in the midguts of A. mellifera adult workers uninoculated with N. ceranae in the control group. 【Conclusion】 This study optimized the structure of PGRP-3 and PGRP-S2 annotated on the A. mellifera reference genome. The splice variant ONT.6350.2-encoded protein is a potential secretary protein, whereas the splice variant ONT.6350.6-encoded protein is a putative intracellular protein. The homology of PGRP-S2 between A. mellifera and A. cerana is the highest. The expression of the splice variants ONT.6350.2 and ONT.6350.6 is activated in response of A. mellifera adult workers to N. ceranae infection.

 【Aim】To clarify the types, morphology and distribution of the antennal sensilla of female and male adults of Anastatus orientalis, an indigenous parasitic natural enemy against Lycorma delicatula, and provide theoretical support for exploring the functions and olfactory mechanisms of various types of sensilla of A. orientalis.【Methods】The morphology and ultrastructure of the antennal sensilla on the female and male adults of A. orientalis were observed with scanning electron microscopy (SEM).【Results】The antennae of adult A. orientalis are geniculate, and consist of scape, pedicel and flagellum. The mean adult antenna length is 1 710.53 μm in males and 1 638.67 μm in females. SEM observation revealed that there are seven types of sensilla on the antennae of adult A. orientalis, including Böhm’s bristles (BBs), sensilla trichodea (ST), sensilla chaetica (SCh), sensilla basiconica (SB, with subtypes SBI and SBII), sensilla placodea (SP), sensilla coeloconica (SCo) and sensilla auricillica (SAu). Among them, the SAu are unique to female adults, and the smell pore (SPo) was also found on the antennae of female adults.【Conclusion】There is typical sexual dimorphism phenomenon in the types and distribution feature of antennal sensilla between the female and male adults of A. orientalis. Different types of antennal sensilla have different morphology and distribution, and play different functions. This research suggests that the abundant antennal sensilla play an important role in the process of sensing environmental changes, finding mates and locating hosts. These results lay a foundation for research on the chemical communication mechanism and olfactory behavior differences of A. orientalis.

【Aim】 Ionotropic receptors (IRs) are crucial for insects’ olfactory, gustatory, temperature, and humidity sensing capabilities. This study aims to identify the IR gene family in Bactrocera dorsalis at the whole-genome level combined with transcriptome data, so as to provide a theoretical basis for further research on the functions of ionotropic receptor genes in B. dorsalis. 【Methods】 IR genes in the whole genome of B. dorsalis were identified by using hidden Markov models, multiple sequence alignments, gene domain analysis, and phylogenetic analysis. Chromosomal localization, full-length gene structure, protein conserved motifs, and collinearity analysis of IR gene family were examined by using TBtools. Evolutionary pressures were assessed with EasyCodeML. Hisat2 and Stringtie software was employed to quantify and analyze the expression patterns of IR genes in the peripheral nervous tissues (antenna, mouthparts, foreleg, midleg, hindleg, and genitalia) of B. dorsalis. qPCR was used for verification. 【Results】 A total of 39 candidate IR genes were identified within the whole genome of B. dorsalis. All the above candidate IR genes were located on autosomes, with 26 of them having complete full-length CDS structures supported by transcriptomic evidence. These full-length IR genes shared 2-8 identical protein conserved motifs, reflecting their structural conservation. Twenty-eight candidate IR genes were demonstrated the collinearity with those of other true flies in the genus Bactrocera, and one IR gene was found to be under strong negative selection. Seventeen candidate IR genes with collinearity were expressed in the peripheral nervous tissues of B. dorsalis, among them, 10 IR genes were exclusively expressed in the antennae, two IR genes only expressed in the mouthparts, and one IR gene solely expressed in the ovipositor. Additionally, one IR gene was expressed only in the antennae and male genitalia, one IR gene was expressed across the tissues except for the ovipositor, two IR genes were expressed across all peripheral nervous tissues, six IR genes were expressed differentially between female and male, and the remaining 11 candidate IR genes showed no expression in peripheral nervous tissues. 【Conclusion】 In this study we systematically identified the IR gene family in B. dorsalis using genomic and transcriptomic data. We analyzed the structural features, evolutionary relationships, and expression patterns of the IR gene family members, providing a theoretical foundation for further functional studies on the IR genes of B. dorsalis.

【Aim】 Using CRISPR/Cas9 gene editing technology to perform single-target knockout of Spodoptera frugiperda doublesex ( Sfdsx), this study aims to explore the effect of Sfdsx on the wing development of male adults of S. frugiperda. 【Methods】CRISPR/Cas9 gene editing technology was used to knock out the female and male common region of Sfdsx in embryos of S. frugiperda and construct Sfdsx mutant. After pupation, the differences in the morphological characteristics of pupa and adult wings of the Sfdsx mutant were observed.【Results】 The Sfdsx mutant of S. frugiperda exhibited significant male-biased sex ratio (female∶male=0∶14), and the genital pores on the 8th-9th abdominal segments of its male pupae were severely twisted. The wing traits of the male adult mutant tended to be neutral in sex, in which，the renal patches in the center of the forewing were deformed, the black spots at the end of the wing disappeared, and the wing scales were arranged in disorder. The hind wings were deformed in wingspan, the arrangement of wing scales changed, and small black spots developed.【Conclusion】CRISPR/Cas9-mediated knockout of the common region of Sfdsx led to wing deformation of male adults of S. frugiperda. The results of our study provide an ideal gene target and theoretical basis to modulate the development of S. frugiperda through sterile insect technology (SIT).

 【Aim】 Based on mitochondrial genome data, we aim to clarify the genetic diversity and genetic structure of the population of Bactrocera dorsalis in Yunnan Province, southwestern China, and reveal the dispersal routes of B. dorsalis in Yunnan, so as to provide the theoretical basis for the formulation and plan of the control strategy of B. dorsalis. 【Methods】 From July to September in 2022, we collected 15 geographical populations of B. dorsalis in Yunnan Province. The mitochondrial genomes were sequenced, assembled and annotated using the DNBSEQ-T7 platform. The genetic diversity and genetic differentiation were detected using MEGA-X 10.0.5, DnaSP 6.12 and Arlequin 3.5.2 software based on the sequences of 13 protein-coding genes (PCGs). The phylogenetic tree was constructed using maximum likelihood method and the haplotype network was constructed using PopART 4.8.4 software based on the sequences of 13 PCGs and COI. The historical dynamics of the populations were analyzed by neutrality test and mismatch distribution. 【Results】 A total of 149 complete mitochondrial genomes from 15 geographical populations of B. dorsalis in Yunnan were obtained， including 1 697 variable sites, showing a high level of genetic diversity (Pi=0.00783, K=87.591，Hd=0.9994). The genetic distance between the populations ranged from 0.00702 to 0.00874, and the genetic differentiation index was from -0.02345 to 0.05203. The phylogenetic tree and haplotype network did not show obvious population structure. The B. dorsalis population expansion occurred in Yunnan. The western and southern regions of Yunnan were the earliest invaded areas of B. dorsalis, while the northern region of Yunnan was one of the invaded areas later. 【Conclusion】 Different groups of B. dorsalis in Yunnan Province showed a high level of genetic diversity and weak genetic structure, and the mitochondrial genome variable sites were abundant and widely distributed in all populations. There was no obvious difference among these geographical populations. It is speculated that B. dorsalis spreads from the western and southern to the northern regions of Yunnan.

 【Aim】This study aims to explore the sublethal effects of chlorpyrifos on Sogatella furcifera, so as to provide a theoretical basis for the rational use of insecticides to control S. furcifera.【Methods】The 3rd instar nymphs of S. furcifera were treated with LC ₁₀ (1.5 mg/L) and LC ₂₅(2.9 mg/L) of chlorpyrifos using rice stem dipping method. The female adult longevity, adult emergence rate and number of eggs laid per female adult of the F ₀ generation were detected. The age-stage, two-sex life table of the F ₁ generation was constructed to analyze the changes in the developmental duration, fecundity and survival rates. The relative expression levels of reproduction-related genes (SfRheb, SfTOR, SfS6K, SfHMGR, SfIPPI, SfFPPS1, SfFPPS2, SfJHAMT, SfFAMeT, SfMet, SfKrh1 and SfVg) in the F ₀ adult females were determined by RT-qPCR.【Results】The numbers of eggs laid per F ₀ female adult of S. furcifera in the treatment groups with LC ₁₀ and LC ₂₅ of chlorpyrifos were significantly reduced, and the adult emergence rate and female adult longevity of the F ₀ generation in the treatment group with LC ₂₅ of chlorpyrifos were shortened significantly, as compared with those in the control group treated with distilled water. The average numbers of eggs laid per F ₁ female adult in the treatment groups with LC ₁₀ and LC ₂₅ of chlorpyrifos were 191.4 and 169.9, respectively， both significantly lower than that in the control group (230.6). Exposure of the 3rd instar nymphs of S. furcifera to LC ₂₅ of chlorpyrifos significantly shortened the female adult duration of the F ₁ generation and reduced the survival rate of the F ₁ generation of S. furcifera, compared to the control. Furthermore, exposure of the 3rd instar nymphs of S. furcifera to LC ₁₀ and LC ₂₅ of chlorpyrifos inhibited the expression of genes (SfFAMeT, SfFPPS1, SfFPPS2 and SfKrh1) related to juvenile hormone (JH) signaling pathways, genes (SfRheb and SfTOR) related to TOR signaling pathways, and SfVg in female adults of the F ₀ generation. 【Conclusion】Sublethal concentrations of chlorpyrifos stress inhibited the growth, development, survival rate and fecundity of S. furcifera, thereby suppressing the population growth of subsequent generations to a certain extent. Furthermore, sublethal concentrations of chlorpyrifos also down-regulated the expression of genes related to the TOR and JH signaling pathways. These findings provide a theoretical basis for the scientific control of S. furcifera in the field and lay a foundation for understanding the molecular mechanisms by which insecticides regulate insect reproduction.

【Aims】 To clarify the morphological and biological characteristics of the tea weevil, Myllocerinus aurolineatus, so as to provide a scientific basis for the accurate identification and the development of green control technologies for this insect pest.【Methods】 M. aurolineatus larvae and adults were reared with field-collected soils and fresh tea branches, respectively, in the laboratory under (25±1) ℃. The main morphological characteristics of M. aurolineatus at various developmental stages were observed under light microscope. Field investigations were conducted to learn the migratory behavior of M. aurolineatus larvae in different soil layers of tea plantation, and the distribution pattern in soil upon pupation. The calling, mating and phototactic behaviors of M. aurolineatus adults were recorded and described with a combination of laboratory observation and behavior test.【Results】The freshly laid eggs of M. aurolineatus are creamy white and gradually turn light yellow. The fleshy larvae have no legs and are usually curved or shaped like the letter C. The naked pupa is milky white with an obvious mouthpart and a pair of wing buds. The mature adults are grayish-black and possess yellowish-green shiny scales and stripes on the sheath wings. And the body size of females is always slightly larger than that of males. M. aurolineatus overwinters in the larval stage in the soil layer of 20-30 cm in depth from the ground and its pupation peak occurs in mid-late April. For pupation, the mature larvae will migrate to the soil layer of 0-10 cm in depth from the ground, and the larvae and pupae in the soil layer of 0-5 cm in depth from the ground accounted for 75.83% of the population. M. aurolineatus adults usually mate from 16:00 to 4:00, and copulate in a “false male-above” position, in which the male sits on top of the female. The whole mating period lasts for 44-132 min, and the mating procedure consists of four stages including pre-copulation, copulation, insemination and post-copulatory mate guarding. In addition, both female and male adults of M. aurolineatus are strongly phototactic in the evening. 【Conclusion】In the present study, the main morphological characteristics of M. aurolineatus at various developmental stages have been clarified, and the vertical migrating behaviors of larvae in the soil of the tea plantation and the vertical distribution patterns in different soil layers during the peak period of pupation have been examined. In addition, the mating and phototactic behaviors of the adults have been preliminarily revealed. The results not only provide references for the accurate identification of M. aurolineatus, but also can give theoretical supports for the development of green control technologies.

 【Aim】 To identify the gustatory receptor (GR) family genes of Anopheles sinensis at the whole genome level, analyze the structure and characteristics of the GR gene family members, and predict the possible biological functions of the GR family members, so as to provide an information framework for the GR family genes of An. sinensis. 【Methods】 Using the known GR amino acid sequences of An. gambiae, Culex quinquefasciatus, Aedes aegypti, and Drosophila melanogaster downloaded from NCBI and Vectorbase databases as inquiry sequences, the GR family genes of An. sinensis were searched and identified at the whole genome level by Blast and HMM methods and named. Using bioinformatics methods, the basic characteristics (physicochemical properties, gene structure and genome localization), conservative domains and Ka/Ks ratios of the GR genes in An. sinensis were predicted. Using MEGA software and maximum likelihood (ML) method, a phylogenetic tree of proteins encoded by the GR genes of An. sinensis and An. gambiae was constructed.【Results】 A total of 54 GR genes were screened and identified in the genome of An. sinensis. According to the classification of An. gambiae and phylogenetic relationship, AsGRs of An. sinensis were divided into four subfamilies of CO₂ receptor, bitter receptor, sugar receptor and pheromone receptor, with 3, 40, 6 and 5 receptors, respectively. CO₂ receptors and sugar receptors were clustered into a single branch, pheromone receptors were clustered into a single branch, and bitter receptors were scattered throughout the phylogenetic tree. The 54 GR genes of An. sinensis were located on the chromosomes Chr.1 and Chr.2. The amino acid numbers of AsGRs are 128-3 429, with the molecular weight of 14.85-397.08 kD, the theoretical isoelectric point (pI) of 5.16-9.84, and the hydrophilicity index (GRAVY) of between -0.023-0.838. The exons of the 54 An. sinensis AsGR genes ranged from 1 to 23, with a wide range. The Ka/Ks ratios of most of the direct homologous gene pairs between An. sinensis and An. gambiae were less than 1, indicating that the GR family genes of An. sinensis were mainly affected by purification selection during the evolutionary process. 【Conclusion】 This study conducted genome-wide identification and characteristic analysis of the GR family genes of An. sinensis, enriching the genome database of An. sinensis and laying a certain foundation for subsequent functional research on the GR genes of An. sinensis.

【Aim】 The aim of this study is to explore the function of the salivary ferritin SaFer1 of Sitobion avenae in the processes of feeding and clarify the effects of SaFer1 on the aphid-plant interactions. 【Methods】 Based on the salivary gland transcriptome data of S. avenae, the full-length cDNA sequence of SaFer1 from S. avenae was cloned, and bioinformatically analyzed. RT-qPCR was used to determine the expression levels of SaFer1 in different developmental stages (1st－4th instar nymphs and wingless adults), different tissues of the 1-day-old wingless adults (head, thorax, abdomen, salivary gland, midgut and embryo), different wing morphs (wingless and winged adults), and the 1st－4th instar nymphs and wingless adults fed on different diets (wheat and artificial diet). With the transient expression system of Nicotiana benthamiana, Agrobacterium tumefaciens was used to mediate the expression of SaFer1 and Bcl-2 associated X protein (BAX) in N. benthamiana leaves, the symptoms of leaf necrosis were observed and used to analyze the functions of SaFer1, and subcellular localization of SaFer1 was observed with the laser scanning confocal microscopy. The yeast secretory system was used to validate the function of the signal peptide of SaFer1. Silencing of SaFer1 in wingless adults was utilized to determine the survival rate and average daily number of aphids produced, and the feeding behavior indexes of the wingless adults on the wheat were detected using the insect electrical penetration graph (EPG) technique. The expression levels of defense-related genes (ROS-related genes NOX and SOD, salicylic acid pathway-related gene PAL, and jasmonic acid pathway-related genes AOS and FAD7) in wheat leaves fed by S. avenae for 3 d after RNAi of SaFer1 were determined by RT-qPCR. 【Results】 The full-length cDNA sequence of SaFer1 (GenBank accession no.: PP760384) of S. avenae was cloned. The cDNA length of SaFer1 is 1 212 bp, and the ORF length is 675 bp, encoding 224 amino acid residues, with the relative molecular mass of 25.5 kD and the isoelectric point of 6.20. The N-terminus of SaFer1 has a signal peptide. SaFer1 had the highest amino acid sequence identity (98.61%) with the unnamed protein (GenBank accession no.: CAI6358877.1) of Macrosiphum euphorbiae. RT-qPCR results showed that SaFer1 was expressed at all developmental stages of S. avenae and is the constitutive expression gene, and was highly expressed in the midgut and salivary glands of the wingless adults. SaFer1 was able to inhibit the leaf necrosis of N. benthamiana induced by BAX. SaFer1 was localized in the leaf cell membrane and nucleus of N. benthamiana. The signal peptide of SaFer1 had secretory activities. Compared to the control group (dsGFP), silencing of SaFer1 caused no significant changes in the survival rates, but resulted in significant decrease in the average daily number of aphids produced by S. avenae. Silencing of SaFer1 resulted in a significant reduction in the duration of E1 waveform, and a significant increase in the duration of waveforms F and G during the feeding process compared to the control group (dsGFP). Silencing of SaFer1 also led to significant upregulation of the expression levels of NOX, SOD, PAL, AOS and FAD7 in wheat leaves compared to the control group (dsGFP). 【Conclusion】 The salivary ferritin SaFer1 of S. avenae was found to be an effector protein, which could help the aphid to feed by inhibiting the host defense responses, enhance the aphid’s fitness, and play vital roles in aphid-host plant interactions.

【Aim】To ascertain the resistance status of Bradysia odoriphaga to ten insecticides, the potential risk of resistance of B. odoriphaga to cyromazine and the sublethal effects of cyromazine on B. odoriphaga. 【Methods】We determined the toxicity of 10 insecticides of 5 categories (neonicotinoids, pyrethroids, pyrroles, insectgrowthregulatorsandorganophosphates) to the 2nd instar larvae of B. odoriphaga from four regions including Puyang City in Henan Province, Bozhou City in Anhui Province, Tangshan City in Hebei Province, and Jining City in Shandong Province with the stomach-contact combination toxicity method. We observed the effects of sublethal concentrations (LC ₁₅ and LC ₃₀) of cyromazine on the larval duration, pupation rate, emergence rate and number of eggs laid per female of B. odoriphaga, and assessed the risk of resistance to cyromazine. We calculated the realized heritability (h ²) of resistance of B. odoriphaga using Tabashnik’s method for threshold trait analysis and predicted the resistance development rates under different selection pressures based on the data of selection. 【Results】 Monitoring data demonstrated that the field populations of B. odoriphaga were susceptible or exhibited low-level resistance to cyromazine, hexaflumuron, chlorfluazuron and pyriproxyfen, and showed low to moderate levels of resistance to phoxim. All the monitored populations of B. odoriphaga showed low-level resistance to beta-cypermethrin. All field populations of B. odoriphaga were susceptible or developed low to moderate levels of resistance to imidacloprid, clothianidin and thiamethoxam. It would take 25.2, 20.7, 17.2, 14.4 and 11.4 generations, respectively, to develop 10-fold resistance to cyromazine in B. odoriphaga, under different selection pressures (mortality rates of 50%, 60%, 70%, 80% and 90%, respectively) when the realized heritability (h ²) of resistance was 0.073. The emergence rates and numbers of eggs laid per female of F ₀ and F ₁ generations of B. odoriphaga were significantly reduced after exposure of the 2nd instar larvae to LC ₁₅ and LC ₃₀ of cyromazine. 【Conclusion】B. odoriphaga has low resistance risk to cyromazine. Cyromazine treatment at sublethal concentrations exhibits significant inhibitory effects on the pupation rate, emergence rate, and number of eggs laid per female of B. odoriphaga.

【Aim】Orthosia songi is a monophagous pest damaging Eucommia ulmoides leaves. The objective of this research is to explore the characteristics of the gut bacterial communities of O. songi larvae at different instars.【Methods】 Illumina HiSeq high-throughput sequencing was employed to investigate the composition and diversity of the gut bacteria of the 1st, 3rd and 6th instar larvae of O. songi from Lüeyang, Shaanxi Province and Lingbao, Henan Province. 【Results】 At the phylum level, the gut bacterial communities of O. songi larvae from the two regions were dominated by Pseudomonadota, Cyanobacteriota, Actinomycetota, Bacillota and Bacteroidota, and the abundance of various phyla differed between samples of larvae at different instars. Notably, the abundance of Pseudomonadota decreased and that of Bacillota increased gradually with the increase of the larval instars of O. songi. At the genus level, Acinetobacter was the dominant bacterium, and its abundance also decreased with the increase of the larval instars of O. songi. Diversity analysis result showed that there were no significant differences in the gut bacterial alpha diversity indexes (Shannon index, Simpson index, ACE index and Chao index) among samples of O. songi larvae at different instars, while the beta diversity of the gut bacterial diversity among samples of O. songi larvae at different instars showed significant difference. 【Conclusion】 The results of this study suggest that the gut bacterial community composition of O. songi larvae collected from Lüeyang, Shaanxi Province and Lingbao, Henan Province is similar, but there is significant difference in the gut bacterial community composition among different larval instars, suggesting that the gut microbiota of O. songi larvae is influenced by their growth and developmental stages.

【Aim】 Junonia coenia densovirus (JcDV) encodes four viral structural proteins, namely VP1, VP2, VP3 and VP4 via leaky scanning. This study aims to explore the expression characteristics of four viral structural protein genes (vp1-4) of JcDV in Spodoptera frugiperda larvae, so as to provide the basis for further studying on the function of the virus structural proteins VP1-4 and the mechanism of their assembly. 【Methods】 The subcellular localization of VP1-4 within Hi5 cells transfected with pJcDV plasmid was detected by immunofluorescence. The expression levels of vp1-4 in the 2nd instar larvae of S. frugiperda at 0, 3, 6, 12, 24, 48, 72, 96 and 120 h after infection by JcDV were analyzed through RT-PCR. The expression levels of VP1-4 in the 2nd instar larvae of S. frugiperda at 0, 24, 48, 72, 96 and 120 h after infection by JcDV were detected by Western blot. Immunohistochemistry was adopted to detect the tissue expression characteristics of VP1-4 in the 2nd instar larvae of S. frugiperda at 0, 24 and 96 h after infection by JcDV. 【Results】 VP1-4 were mainly located in the cytoplasm of Hi5 cells and only distributed in small amounts in the nucleus in the form of polymers. The transcription of vp1-4 could be detected in the 2nd instar larvae of S. frugiperda at 3 h after infection by JcDV, and stably extended to at least 120 h. VP1-4 were expressed at 24－120 h after infection by JcDV. The expression of VP1-4 was detected in the cuticle and trachea of the 2nd instar larvae of S. frugiperda at 96 h after infection by JcDV, however, there were no obvious expression signals in the muscle and fat body. 【Conclusion】 The transcription and translation of the viral structural protein genes vp1-4 could be detected in the 2nd instar larvae of S. frugiperda at 3 and 24 h, respectively, after infection by JcDV, indicating that VP1-4 might play an important role in the early stages of infection. JcDV could infect the cuticle and trachea of S. frugiperda larvae, which might be one of the causes accounting for their death.

 RNA interference (RNAi) has been widely applied in the study of gene function in insects and the development of novel biological strategies for the selective control of agricultural pests due to its high conservation, strong specificity, easy operation and efficient silencing. However, the practical application of RNAi in pest control also faces challenges, among which the efficiency of RNAi is the most significant limiting factor. In this review, we summarized and discussed the three main pathways of the molecular mechanisms of RNAi, the impact of nucleases on the stability of doublestranded RNA (dsRNA) and RNAi efficiency, and the research progress in using nanoparticle materials to encapsulate and deliver dsRNA. We also provide a perspective on improving RNAi efficiency by inhibiting nuclease activity in insects and combining it with target gene dsRNA, with the aim of providing references for the biological control of pests and the development of green insecticides based on nanoparticles. One of the main factors limiting the efficiency of RNAi in insects is the stability of dsRNA. Combining dsRNA with different nanoparticles to form polymers can increase the stability of dsRNA in insects, thereby enhancing RNAi efficiency. Different nanoparticles provide various ways to deliver dsRNA in RNAi applications. Nanoparticles, with their advantages of safety, low-toxicity, low-cost, good biocompatibility and high RNAi efficiency, have become a research hotspot in both domestic and international research, and are increasingly applied in insect RNAi studies, demonstrating great potential and value in pest control and the development of green insecticides. In the future, the functional design of nanomaterials should be enhanced, low-cost production processes should be developed, and an ecological risk assessment system should be established to promote the practical application and sustainable development of RNAi technology in agriculture.

【Aim】 This study aims to explore the effects of environmental factors such as photoperiod, sunset time and light intensity in the light-dark cycle on the circadian rhythm in oviposition of Grapholita molesta adults, and to provide a basis for developing control measures based on light interference with oviposition. 【Methods】 The circadian rhythm in oviposition of G. molesta adults was observed under natural light environment in the field in spring, summer and autumn, and the differences in oviposition rhythm were compared and analyzed under different photoperiods (15L∶9D, 14L∶10D and 13L∶11D), simulated sunset time (19:00 and 16:00) and different intensities (1 000, 500, 100, 50, 10, 5, 1, 0.5 and 0.1 mW/m²) of dim light interruption (1 h) in artificial climate chambers. 【Results】 G. molesta adults showed obvious oviposition rhythm under natural light environment in the field. In spring, summer and autumn (the sunset time was 18:30, 19:30 and 18:30, respectively), the oviposition peaks of G. molesta adults occurred at 18:00-19:00, 19:00-20:00 and 18:00-19:00, respectively, i. e., within 0.5 h before and after sunset. During this period, the light intensity changed dramatically, rapidly decreasing from 10 000 mW/m² to 0.01 mW/m2. There was no obvious difference in oviposition rhythm of G. molesta adults under different photoperiods (15L∶9D, 14L∶10D and 13L∶11D) at the same sunset time, showing a similar “unimodal” curve. When the simulated sunset time was 19:00 and 16:00, the oviposition rhythms of G. molesta adults were obviously different, and the oviposition peaks occurred at 19:00-20:00 and 16:00-17:00, respectively, i. e., 1 h after sunset, accounting for more than 54% of the daily total number of eggs laid. The oviposition rhythm of G. molesta adults changed under the dim light interruption environment before sunset. Compared with the “bimodal” curve with small front and large back under 1 000, 500 and 100 mW/m² of dim light interruption, the “bimodal” curve with large front and small back was observed in the oviposition rhythm of adults under 50, 10, 5, 1, 0.5 and 0.1 mW/m² of dim light interruption, with the oviposition peak occurring at 16:00-17:00 (i. e., during the dim light interruption period)(more than 40% of oviposition percentage), followed by that at 19:00-20:00. There were significant differences in the daily numbers of eggs laid per female under different intensities of dim light interruption, with the highest daily numbers of eggs laid per female (33.05 and 31.00 grains, respectively) under 0.5 and 0.1 mW/m² of dim light interruption， respectively.【Conclusion】Light-dark cycle and light intensity can affect the circadian rhythm in oviposition of G. molesta adults, and oviposition activities mainly occur in dim light (below 50 mW/m²) or darkness.

【Aim】This study aims to ascertain the predation capability and biological control potential of the syrphid, Eupeodes corollae against the nymphs and female adults of the mealybug, Phenacoccus solenopsis.【Methods】The predation capabilities of the 1st-3rd instar larvae of E. corollae on the 1st-3rd instar nymphs and female adults of P. solenopsis at different densities were tested under laboratory conditions. The Holling and Hassell models were used to fit the predatory functional response and intraspecific interference response of E. corollae to P. solenopsis.【Results】Preying on P. solenopsis, E. corollae larvae exhibited searching, probing, attacking and feeding behaviors. The predation rates of the 1st-3rd instar larvae of E. corollae on nymphs and female adults of P. solenopsis increased with the developmental stages of E. corollae increasing. Moreover, the predation rates of the 1st-3rd instar larvae of E. corollae on P. solenopsis nymphs were higher than those on female adults of P. solenopsis. In a certain range of prey densities, the predation of the 1st-3rd instar larvae of E. corollae on the 1st and 2nd instar nymphs of P. solenopsis fitted the Holling type Ⅲ functional response model, the instantaneous attacking rates were positively correlated with the prey densities, and the prey handling time decreased and the theoretically maximum daily predation amount of prey increased as the developmental stages of E. corollae increased. The predation of the 1st-3rd instar larvae of E. corollae on the 3rd instar nymphs and female adults of P. solenopsis fitted the Holling type Ⅱ functional response model, the daily predation amount was positively correlated with the prey density, and the instantaneous attacking rate of E. corollae against prey increased, the theoretically maximum daily predation amount of prey and predation capability also increased while the prey handling time decreased with the increase of the developmental stages of E. corollae. The predation rates of the 1st-3rd instar larvae of E. corollae to female adults of P. solenopsis were negatively correlated with the predator densities, indicating an increase in intraspecific interference with the increase of predator density.【Conclusion】Taken together, these results indicate that E. corollae larvae have good control potential on the nymphs and female adults of P. solenopsis. The current study provides a theoretical basis for evaluating the biological control potential of E. corollae larvae against P. solenopsis.

【Aim】 The aim of this study is to investigate the effects of different protease inhibitors on the protease activities in the larval midguts of Janus piri and Dasineura pyri. 【Methods】 The midgut pH values and the activities of four proteases (total protease, high-alkaline trypsin, low-alkaline trypsin and chymotrypsin) in the midguts of the 2nd-5th instar larvae of J. piri and the 1st-4th instar larvae of D. pyri were determined by biochemical techniques. The effects of 10 inhibitors on the protease activities in the larval midguts of the two insect species were further determined at the optimum pH and larval instar. 【Results】 The mean pH values in the larval midguts of J. piri and D. pyri were 8.2 and 7.6, respectively, and the activities of the four midgut proteases were the highest in the 3rd instar larvae of the two insect species. The most effective inhibitor for total protease activity in the midgut of J. piri larvae was 5 mmol/L EDTA, followed by 1 mmol/L TPCK. For high-alkaline trypsin activity in the midgut of J. piri larvae, the most effective inhibitor was 1 mmol/L TPCK, while for low-alkaline trypsin activity, the best inhibitory effect was achieved with 10 mmol/L PMSF. The most effective inhibitor for chymotrypsin activity in the midgut of J. piri larvae was 5 mmol/L EGTA. In the midgut of D. pyri larvae, the most effective inhibitor for total protease activity was 1 mmol/L TPCK, followed by 50 μg/mL STI. For high-alkaline trypsin activity in the midgut of D. pyri larvae, the best inhibitory effect was achieved with 5 mmol/L EDTA, while for low-alkaline trypsin activity, 10 mmol/L EDTA showed the best inhibitory effect. The most effective inhibitor for chymotrypsin activity in the midgut of D. pyri larvae was 50 μg/mL STI. 【Conclusion】 TPCK, STI and EDTA had better inhibitory effects on the total protease activities in the larval midguts of J. piri and D. pyri, EDTA and EGTA had better inhibitory effects on their larval midgut high-alkaline trypsin activities, PMSF, EDTA and TPCK had better inhibitory effects on their larval midgut low-alkaline trypsin activities, and EGTA had a better inhibitory effect on their larval chymotrypsin activities. The results provide some theoretical reference value for the development of new biopesticides related to insect midgut proteases and inhibitors.

【Aim】 This study aims to clone the matrix metalloproteinase-14 gene AcMMP14 in Apis cerana and to analyze its molecular characteristics and expression pattern, so as to offer the reference and basis for continuous and further functional study of AcMMP14. 【Methods】 Total RNA from the 6-day-old larval gut of A. cerana workers was extracted, and the coding sequence (CDS) of AcMMP14 was amplified by PCR. Relevant bioinformatic software was employed to predict the physicochemical property and molecular characteristics of AcMMP14, to identify structural domains and conserved motifs in MMP14s from A. cerana and other bee species, followed by phylogenetic analysis. RT-qPCR was utilized to detect the relative expression levels of AcMMP14 in egg, larva, prepupa, pupa and different day-old adult workers, and antenna, brain, cuticle, fat body, venom gland, midgut and hypopharyngeal gland of the adult workers, and the relative expression levels of AcMMP14 in the midgut of the newly emerged 1-day-old adult A. cerana workers at 1-4 d post inoculation with Nosema ceranae. 【Results】 AcMMP14 has a molecular formula of  C₃₀₆₈H₄₅₈₁N₈₀₃O₉₁₅S₂₀, a molecular weight of about 68.00 kD, a liposoluble coefficient of 64.12, a theoretical isoelectric point of 5.85, and an average hydrophilic coefficient of -0.47. AcMMP14 contains one signal peptide and 36 phosphorylation sites, and can be simultaneously located in mitochondria, nucleus and cytoplasm. Three same structural domains and five same conserved motifs were included in MMP14 proteins from A. cerana and other 10 bee species. MMP14 of A. cerana and A. dorsata had the amino acid sequence identity of 94.23% and clustered into one clade on the phylogenetic tree. AcMMP14 was differentially expressed in egg, 3-day-old larva, 1- and 2-day-old prepupae and 4-day-old pupa of A. cerana workers, and the expression level of AcMMP14 was the highest in the 4-day-old pupa and significantly higher than those in the 3-day-old larva and 2-day-old prepupa. AcMMP14 was differentially expressed in different day-old adult workers, and the expression level of AcMMP14 was the highest in the 15-day-old adult and significantly higher than those in the 1-, 2-, 6-, 12- and 17-day-old adult. AcMMP14 was differentially expressed in the seven tissues of adult workers, and the expression level of AcMMP14 was the highest in the antenna and significantly higher than those in the brain, cuticle, fat body, venom gland, midgut and hypopharyngeal gland. The expression levels of AcMMP14 in workers’ midguts of adults at 1 and 2 d post inoculation with N. ceranae were significantly down-regulated, while those in workers’ midguts of adults at 3 and 4 d post inoculation with N. ceranae were down-regulated without significant difference as compared with those of the control group. 【Conclusion】 AcMMP14 is a potential hydrophilic and secretary protein. AcMMP14 plays a putative key role at different developmental stages and in different adult tissues of A. cerana workers. AcMMP14 in the adult worker’s midgut is activated and expressed at early stage of the 1st proliferation cycle of N. ceranae.

 【Aim】Plutella xylostella is a worldwide pest of cruciferous vegetables. This study aims to confirm the effects of opsin gene LW-opsin mutation on the growth, development, and fecundity of P. xylostella, providing a theoretical basis for the development of new target of genetic control of P. xylostella. 【Methods】Under laboratory conditions, the age-stage, two-sex life table was employed to determine the developmental duration, survival rate, fecundity, life expectancy and life table parameters of the wild-type strain G88 and the LW-opsin mutant strain LW-13 of P. xylostella. 【Results】LW-opsin mutation prolonged the preadult duration ［G88: (12.45±0.06) d; LW-13: (13.45±0.25) d］ and the total preoviposition period［G88: (12.59±0.08) d; LW-13: (13.57±0.30) d］, and shortened the adult longevity ［G88: (6.84±0.02) d; LW-13: (5.73±0.07) d］ and oviposition period ［G88: (6.09±0.10) d; LW-13: (5.14±0.34) d］. The survival rates of larva, pupa and adult were decreased by LW-opsin mutation. The age-specific survival rate of the G88 strain began to decline sharply from the 18-day-old, while that of the LW-13 strain had dropped to 25% at the 4-day-old. LW-opsin mutation reduced the age-specific reproductive value, age-stage-specific life expectancy, intrinsic rate of increase ［G88: (0.31±0.01) d-1; LW-13: (0.15±0.03) d-1］, finite rate of increase ［G88: (1.36±0.01) d-1; LW-13: (1.16±0.03) d^-1］ and net reproductive rate (G88: 79.79±8.84; LW-13: 10.26±3.84) of P. xylostella, and prolonged the mean generation time ［G88: (14.20±0.06) d; LW-13: (15.67±0.16) d］. 【Conclusion】 Opsin gene LW-opsin mutation affects the growth and development of P. xylostella, reducing its survival rate and fecudity.