【Aim】To understand the effects of habitat changes on the bacterial communities in the larval gut of chironomids by studying the diversity and potential function of bacterial communities in the gut of Propsilocerus akamusi, a pollution-resistant chironomid identified in the freshwater area of the heavy metal polluted Bohai Bay of Tianjin City. 【Methods】The 4th instar larvae of P. akamusi identified in the freshwater area of the heavy metal polluted Bohai Bay of Tianjin City were raised with distilled water in laboratory for 7 d as the laboratory-cultured group, and the bacterial genomic DNA in the 4th instar larval gut of P. akamusi from the laboratory-cultured group and the wild-captured group was extracted. The high-throughput sequencing of the V3-V4 region of 16S rRNA gene was carried out, and the sequencing results were subjected to data quality control, sequence alignment and filtering, the changes in the species composition of gut bacterial communities were analyzed and the potential functions of gut bacteria were predicted. 【Results】Based on the 16S rRNA sequencing results of the gut bacteria in the 4th instar larvae of P. akamusi, 11 phyla, 13 classes, 33 orders, 54 families, 71 genera, 90 species and 105 operational taxonomic units (OTUs) were annotated. The diversity and abundance of bacterial communities in the 4th instar larval gut of P. akamusi in the laboratory-cultured group were lower than those in the wild-captured group. The dominant bacterial phyla in the 4th instar larval gut of the two groups were similar, including Firmicutes, Proteobacteria, Bacteroidota and Desulfobacterota. The abundance of Proteobacteria in the 4th instar larval gut of the wild-captured group was significantly higher than that in the laboratory-cultured group. The average abundance of Aeromonas, Shewanella, Serratia, Pseudomonas and Yersinia in the 4th instar larval gut in the laboratory-cultured group was significantly lower than that in the wild-captured group. The results of linear discriminant analysis revealed that there were bacterial species with significantly different abundance in the 4th instar larval gut of P. akamusi between the wild-captured group and the laboratory-cultured group. The KEGG analysis results showed that the relative abundance of metabolism-related genes in the bacterial genome of the 4th instar larval gut of P. akamusi was extremely high. The relative abundance of genes related to environmental information processing and cellular processes in the gut bacterial genome of the 4th instar larva of P. akamusi in the laboratory-cultured group significantly decreased as compared to that in the wild-captured group.【Conclusion】The results of this study indicate that there are significant differences in the diversity of the gut bacterial communities and gene functions between P. akamusi larvae living in adverse field environments and those reared in laboratory pure water environments. This helps to study the individual resistance mechanisms of chironomids from an environmental perspective, provides a new idea for further exploring the mechanism of the symbiotic microorganisms in the gut of chironomid larvae to cope with environmental stress, and also lays a foundation for the study of the tolerance mechanism of insects in adverse environmental conditions and the regulatory mechanism of homeostasis of their gut microbial communities.

Insect symbionts are microorganisms that establish enduring and sustained associations with insect hosts. These microorganisms inhabit the body surface, gut, hemocoel, or intracellular cells of insects, participating in the regulation of various physiological functions of their host insects. Research on insect-symbiont interactions involves multidisciplinary collaboration. In-depth exploration of the functions of insect symbionts and their interactions with hosts not only advances our understanding of fundamental mechanisms in the life sciences but also introduces innovative perspectives and methods for pest management, vector-borne disease control, and optimal utilization of beneficial insects. In recent years, Chinese researchers have made noteworthy progress in the insect microbiome and got significant achievements in many research directions. In this article, we provided an overview of the most recent research progress in insect symbionts, introduced the main contents of this special issue, and proposed three noteworthy research directions: (1) the functions of insect intracellular symbionts; (2) the mechanisms by which insects regulate the abundance and transmission of symbionts; and (3) genetic modification and application of insect symbionts.

The tomato leafminer, Tuta absoluta, is native to South America and a quarantine pest in the world nowadays, which can reduce the yield of the main host crop tomato by 80%-100% in severe cases. In over a decade, this insect pest has invaded and spread from its origin to almost the entire continent of Asia, Africa and Europe, becoming a major threat to the world tomato industry. T. absoluta was discovered in Ili, Xinjiang in 2017 and spread to Yunnan, Gansu and other regions in a short time, greatly threatening the healthy development of the tomato industry and other related agricultural industries in China. Internationally, sex pheromone-based monitoring, mass trapping and mating disruption control have become one of the important  measures to control T. absoluta. In order to study the efficient and environmentally friendly population dynamics monitoring and control technology of T. absoluta, we summarized the research and application status of the sex pheromone in mornitoring, early warning and control of T. absoluta in this article. The females of T. absoluta release sex pheromones to attract males to mate mainly in the morning, and adult mating reaches the peak at 7:00 a.m. In 1995 and 1996, the major and minor components of the sex pheromone released from T. absoluta and their synthetic methods were reported successively. The major and minor components of this sex pheromone are (3E, 8Z, 11Z)-tetradecatrienyl acetate (TDTA) and (3E, 8Z)-tetradecadienyl acetate (TDDA), respectively, which constitute the sex pheromone in a ratio of about 90∶10. Bioassay results revealed that TDTA had a strong attraction to males, which could be further enhanced when its mixture with TDDA was used. In recent years, more efficient and convenient synthetic methods of sex pheromone components have been developed, providing good conditions for their large-scale production and application. At present, the sex pheromone of T. absoluta has been widely used in the control of this insect pest in the world, and good results have been achieved. Among the reported sex pheromone traps commonly used for monitoring and mass trapping this insect pest, the water basin trap and triangle trap are more effective. The common doses of sex pheromone contained in commercial lure core are 0.5, 0.8 and 3.0 mg. For field application, the corresponding trap type and sex pheromone dose should be selected according to the actual situation of habitat and growth stage of crops, damage degree, local natural conditions, etc. In addition, the mating disruption by using sex pheromone is also common in the control of T. absoluta, and its successful application requires a highly enclosed environment. Because sex pheromone has the advantages of high efficiency, safety and environmental protection in the monitoring and control of T. absoluta, its related research results can provide important reference for the sustainable control strategies and measures of this insect pest in China.

【Aim】To explore the effects of oviposition season and geographical latitude on  life history traits of the Japanese pine sawyer beetle, Monochamus alternatus, so as to  provide a basis for the accurate prediction and management of this insect pest.【Methods】 Six monitoring plots along the latitudinal gradient of about 1° in Jiangxi Province,  Southeast China were established, then the generation differentiation and developmental  duration were investigated by field pine tree trunk covering observation, and the  overwintering larval instars were surveyed through dead wood dissecting.【Results】The 2nd  generation differentiation of M. alternatus occurred in southern and central Jiangxi. The  proportion of the differentiation entering the 2nd generation decreased from 45.75% to 2. 46% in southern Jiangxi and from 17.42% to 0 in central Jiangxi with the delay of  oviposition season, while there was only one generation in northern Jiangxi, where no  generation differentiation occurred. The proportion of the eggs laid at the same month  entering the 2nd generation decreased from 21.92% to 0 with increasing geographical  latitude. The egg-pupal duration in differentiated and undifferentiated individuals in the  forest was 110.66-122.01 and 330.61-366.01 d, respectively, and showed a latitudinal  co-gradient variation and a counter-gradient variation, respectively. However, no  significant difference was found in the developmental duration of differentiated and  undifferentiated individuals. The overwintering larvae were at the 2nd-5th instars in  southern and central Jiangxi and 4th-5th instars in northern Jiangxi, and the proportion of  the 2nd instar overwintening larvae significantly decreased from 12.47% to 0 and the  proportion of the 5th instar overwintering larvae significantly increased from 45.33% to  98.40% with increasing geographical latitude.【Conclusion】Oviposition season and  geographical latitude have certain effects on the life history traits of M. alternatus,  showing that oviposition season and geographical latitude significantly affect the  generation differentiation proportion of this beetle, but not on the developmental duration  of differentiated individuals and undifferentiated individuals. The larval instars and  proportion of overwintering insects are obviously affected by geographical latitude.

The South American tomato pinworm, Tuta absoluta, is a worldwide devastating pest on tomatoes. This insect pest invaded China in 2017 and showed a trend of spread, posing a serious threat to tomato production in China. Unreasonable use of insecticides for control of this insect pest has led to the increasing level of resistance and the decrease of control efficacy. Consequently, there is an urgent need to develop novel green control technologies. Physical control trapping technique and olfactory behavior manipulation technique are important components of the integrated pest management program. In this article, the research progress of physical control trapping (light traps and color traps) and olfactory behavior manipulation (sex pheromone and plant volatiles) in T. absoluta were summarized. Color significantly affects the trapping efficiency of pheromone traps and sticky color traps. White, black and blue traps attract more T. absoluta adults in the field. The black light traps and LED traps with the wavelength of 470 nm have the best trapping efficiency on T. absoluta, and also have synergistic effects on sex pheromone. The sex pheromone of T. absoluta includes the major component (3E, 8Z, 11Z)-tetradecatrienyl acetate and the minor component (3E, 8Z)-tetradecadienyl acetate, in a ratio of ~9∶1. The optimal trapping blend for mass trapping is (3E, 8Z, 11Z)-tetradecatrienyl acetate and (3E, 8Z)-tetradecadienyl acetate in a ratio of 95∶5, and delta traps with sex pheromone lure show the highest trapping efficiency in comparison with other trap types. The sex pheromone of T. absoluta has been widely used for monitoring, mass trapping and mating disruption. Plant volatiles and traditional food attractant volatiles affect the host selection and oviposition of T. absoluta. Octyl acetate, phenylacetaldehyde+acetic acid blend, acetic acid+3-methyl-1-butanol blend, and a blend consisting of limonene, β-ocimene, α-terpinene, δ-elemene and (E)-β-caryophyllene show attractive activities to T. absoluta. p-Quinone, 2-carene, d-curcumene and 1,2-diethylbenzene in tomato can serve as oviposition stimulants to T. absoluta. By contrast, 1-fluorododecane, caryophyllene, curcumene, elemene, humulene, zingiberene, tridecan-2-one, undecan-2-one, (Z)-3-hexenyl propanoate and methyl salicylate have adverse effects on host selection, oviposition or growth and development of T. absoluta. Finally, current problems of behavioral manipulation techniques of T. absoluta, such as unclear mechanisms, unstable effects, and lack of combined application technology with other green control strategies, were discussed, and potential research directions were prospected, which will provide a reference for the development of green control technologies based on insect behavioral manipulation in this pest.

【Aim】To evaluate the toxicity and ecological risks of the formulations of seven neonicotinoid insecticides to the 7-spot ladybird, Coccinella septempunctata, so as to provide a reference for scientific use of neonicotinoid insecticides and protection of C. septempunctata.【Methods】The acute toxicity of the formulations of seven neonicotinoid insecticides, including 10% imidacloprid WP, 40% acetamiprid SP, 50% dinotefuran WP, 50% clothianidin WG, 40% imidaclothiz WG, 17% flupyradifurone SL and 25% thiamethoxam WG to the 2nd instar larvae of C. septempunctata was determined by using the method of residual film in glass tube, and the ecological risks of these insecticides were assessed. The solutions of the seven insecticides were prepared according to the maximum recommended field application rate, and sprayed on potted plants in the greenhouse to investigate the larval survival rate of C. septempunctata.【Results】The results of the indoor experiments showed that the acute toxicity of the seven neonicotinoid insecticides to the 2nd instar larvae of C. septempunctata was ranked in a descending order: 40% acetamiprid SP>40% imidaclothiz WG>10% imidacloprid WP>50% dinotefuran WP>50% clothianidin WG>25% thiamethoxam WG>17% flupyradifurone SL. The pot experiment in the greenhouse showed that the larval survival rates of C. septempunctata at 7 d after treatment with the seven insecticides at the maximum recommended field application rate were 10.00%-77.50%, and the highest larval survival rate of C. septempunctata was tested in the treatment with 25% thiamethoxam WG, while the lowest survival rate was observed in the treatment with 40% imidaclothiz WG. The results of ecological risk assessment showed that for a single application, the risk of 40% acetamiprid SP was unacceptable with the hazard quotient value in the farm (HQ_in) of more than 5, and those of the other pesticides were acceptable with the HQ_in values of less than 5. The hazard quotient values for crop or vegetable field outside the farm (HQ_{off crop or vegetable}) and for fruit tree garden outside the farm (HQ_{off fruit tree}) of these insecticides to C. septempunctata were less than 5, indicating that the risk is acceptable. After the second spray after 7 d, the risks of 40% acetamiprid SP and 50% dinotefuran WP were unacceptable with the HQ_in values of more than 5, and those of the other insecticides were acceptable with the HQ_in values of less than 5. The HQ_{off crop or vegetable} and HQ_{off fruit tree} values of the other insecticides except 40% acetamiprid SP were less than 5, indicating that the risks of these insecticides are acceptable.【Conclusion】Acetamiprid and dinotefuran should not be used twice continuously and be used in rotation in order to avoid harm to C. septempunctata.

【Aim】 Altitudinal gradient has an important impact on the distribution and maintenance of insect species. This study aims to provide a theoretical basis for studying the impact of altitudinal gradient on insect distribution by exploring the variation law and distribution characteristics of species diversity of rove beetles at different altitudinal gradients in the reserve.【Methods】From May 2020 to April 2021, three kinds of passive acquisition devices, flight interception trap, Malaise trap and pitfall trap, were used in Mangshan National Nature Reserve, Hunan Province, Central China to investigate the species of rove beetles at the altitudinal gradients of 500-800 m (Ⅰ), 800-1 100 m (Ⅱ), 1 100-1 400 m (Ⅲ) and 1 400-1 700 m (Ⅳ), and the species diversity, community structure similarity and species abundance of rove beetles at different altitudinal gradients were analyzed using Excel 2016 and past 3.【Results】From May 2020 to April 2021, we collected and recorded 2 135 rove beetles in Mangshan National Nature Reserve, Hunan Province, belonging to 9 subfamilies, 45 genera and 111 species, of which the number of species in Staphylininae was the most (25 genera and 63 species), and the numbers of species in Steninae and Oxytelinae were the least (both 1 genus and 1 species). The Shannon-Wiener diversity index, Mangalef richness index, Berger-Parker dominance index and Pielou’s evenness index of rove beetles were 3.8280, 2.3920, 0.1217 and 0.4140, respectively. There were differences in species diversity indexes of rove beetles at different altitudinal gradients. The species number, individual number, Shannon-Wiener diversity index and Margalef richness index of rove beetles at the altitudinal gradient Ⅲ were significantly higher than those at the altitudinal gradient Ⅰ. The species of rove beetles were poor and the dominant species were prominent at the altitudinal gradient Ⅰ, but the community structure was relatively stable. Altitudinal gradient Ⅱ was the transition gradient from low altitude to medium altitude. The species of rove beetles were rich, the community structure was complex, the dominant species were prominent and concentrated, and the community structure was relatively unstable at the altitudinal gradient Ⅲ. The species of rove beetles at the altitudinal gradient Ⅳ were relatively poor as compared with those at the altitudinal gradient Ⅲ. The similarity coefficient between the altitudinal gradient Ⅲ and altitudinal gradient Ⅳ was the highest, showing medium similarity, while those between other altitudinal gradients showed medium dissimilarity.【Conclusion】 The results of this study suggest that there are great differences in the distribution characteristics of rove beetles among different altitudinal gradients. Rove beetle species are poor and the community structure is single in low altitude areas. The medium altitude area is rich in rove beetle species, and has complex community structure and prominent dominant species. Compared with the medium altitude area, the high altitude area is relatively poor in rove beetle species. The similarity coefficient of rove beetle species between the medium-high altitude area and the high altitude area is the highest.

True fruit flies are important insect pests attacking fruits and vegetables. The total damage caused by them worldwide is estimated to amount to be more than 2 billion US dollars annually. The oriental fruit fly, Bactrocera dorsalis, is one of the representatives of this kind of pests, causing serious losses to China’s citrus industry every year. The techniques based on male attractant and protein bait have been used in environment friendly strategies for pest monitoring and control. However, the performances of those baits in the field are unsatisfied and need to be further improved. With the reduction of the cost of high-throughput sequencing technology and the development of modern molecular biology technology, scientists proposed to discover the key molecular targets for olfaction by resolving the molecular mechanism of pest chemosensory first and develop more stable and efficient attractants with the identified new targets. In order to promote the development of behavioral regulation technology targeting key chemosensory molecules in B. dorsalis, we reviewed the research status of important chemicals regulating the behavior of B. dorsalis and the mechanism of chemosensory perception in this article. The important volatiles regulating the behavior of B. dorsalis include sex pheromones, plant volatiles and food-derived protein odors. Among them, the specific compounds identified by the first two have a clear relationship with the behavior of B. dorsalis adults. For example, pyrazine substances obtained from sex pheromones can attract females, methyl eugenol in plant volatiles can attract males, γ-octalactone can induce females to lay eggs; while the composition of food-derived protein odor is complex, although it has a certain efficacy in the field, there is a lack of function validation of specific compounds in female and male insect behavior. In the olfactory sensory mechanism, there is only a morphological description of the peripheral nerve sensilla and the central antennal lobe, and the function of different types of olfactory neurons is not clear. A large number of chemical sensory proteins have been identified in B. dorsalis, including 49 odorant binding proteins (OBPs), 60 odorant receptors (ORs), 23 ionotropic receptors (IRs) and 17 gustatory receptors (GRs), through bioinformatics analysis at present. However, the number of olfactory genes functionally analyzed is small. In conclusion, although some compounds with behavioral activity on B. dorsalis have been identified, and a large number of olfactory proteins have been used as candidate molecular targets, the corresponding relationship between “chemical substances-olfactory molecular targets and nerve-behavior” is lacking, which greatly limits the role of olfactory molecular targets in attractant development. Therefore, on this basis, we put forward a development strategy for the behavioral regulation technology of B. dorsalis based on olfactory key molecular targets, to provide new ideas for the design and screening of effective behavioral regulators of B. dorsalis.

【Aim】Juvenile hormone (JH) and ecdysone (Ecd) play important roles in the growth and development of insects. The aim of this study is to clarify the regulatory mechanism of these two hormones and their metabolism-related genes on the development of Calliptamus italicus eggs.【Methods】The changes in contents of JH and Ecd during the development of C. italicus eggs were detected by ELISA assay, and the expression patterns of important genes (JHE, JHEH, DIB and EcR) in the metabolic pathways of JH and Ecd during the development of C. italicus eggs were detected by qRT-PCR.【Results】The JH content in C. italicus eggs was significantly higher at the diapause stage (stages Ⅳ-Ⅵ) than at the early developmental stage (stages Ⅰ-Ⅲ), and decreased significantly at the post-diapause developmental stage (stages Ⅶ-Ⅸ). The Ecd content in C. italicus eggs increased significantly at the early diapause stage (stage Ⅳ), then decreased significantly, and increased again at the post-diapause developmental stage. The expression level of JHE in C. italicus eggs increased firstly and then decreased at the early developmental stage and the post-diapause developmental stage, and was low at the diapause stage. The expression level of JHEH in C. italicus eggs also increased first and then decreased at the early developmental stage, and didn’t change significantly at the diapause stage, but increased significantly at the post-diapause developmental stage. The expression level of DIB in C. italicus eggs was higher at the diapause stage than at the early developmental stage and decreased at the post-diapause developmental stage. The expression level of EcR in C. italicus eggs did not change significantly at the early developmental stage and diapause stage, but increased gradually at the post-diapause developmental stage. 【Conclusion】The development of C. italicus eggs is co-regulated by JH and Ecd. JH is the important hormone to regulate diapause entry, while Ecd is the important hormone for diapause termination of C. italicus eggs. JH catabolic pathway of C. italicus eggs is mainly regulated by JHE before diapause termination and by JHEH after diapause termination. DIB and EcR can affect the development of C. italicus eggs by regulating Ecd content. These results lay a foundation for further revealing the diapause mechanism of C. italicus eggs.  

Successfully locating a host is one of the crucial steps in parasitoid  reproduction, which is regulated mainly by volatile compounds. Firstly, female parasitoids  often use volatiles from host plants, especially herbivore-induced plant volatiles  (HIPVs), to locate the habitat of their hosts at long distances, which helps female  parasitoids narrow their host searching range according to the cues provided by HIPVs. The  blends of HIPVs are extremely complicated, and their components and contents can be  modulated by a wide range of factors. Nevertheless, terpenoids are common compounds in  HIPVs and have been confirmed by most behavioral studies to play a role in host  localization of parasitoids. Subsequently, when the parasitoids find a plant related to  hosts and land on them, they exploit host-derived cues at a close range to locate hosts.  Parasitoids are usually attracted to volatile compounds released from the host body,  cocoon, feces, etc. The odor of some host feces can be used as the main cues for  parasitoids to locate hosts. Moreover, the components of volatiles in host feces may vary  among plant species which insects feed. In addition, semiochemicals from the parasitoid  itself are also beneficial for other individuals of the same species to locate their hosts.  Sensory perception of odor molecules by parasitoids relies on olfactory sensilla, primarily  located on the antennae, but the research on the molecular mechanism of their olfactory  recognition is still limited. Because odorant-binding proteins (OBPs) are the crucial  proteins in the olfactory system that mediate odor recognition, most studies only focus on  the analysis of antennal OBPs. According to the current research, the number of genes  encoding OBPs is highly variable among parasitiod species, and most studies have verified  that OBPs play an important role in host location of parasitoids by means of gene  silencing, fluorescence competitive binding assay, molecular docking and so on. Research on  host localization and olfactory mechanism of parasitoids has important ecological  significance, and also has a good application perspective in the integrated management of  agricultural insect pests. Applying volatile compounds, or growing companion plants and  transgenic plants that emit useful volatiles can enhance the host location of parasitoids  in the field, so as to achieve a better biological control efficacy against insect pests.

The collective set of odors received by insects is called as insect odorscape. Insects rely on the reception and discrimination of the odorscape to complete life activities, such as the object localization, feeding, mating and oviposition. The behavior of insects can be manipulated by odorscape management for pest control strategy. In this article, we reviewed the research progress in the composition and diffusion of insect odorscape, influences of odorscape on insect behavior, factors affecting odorscape, odorscape reception and discrimination of insects, and the application of odorscape management in pest control. Finally, we analyzed and prospected the development direction and research focus of insect odorscape management in the future. For insects, the odor released by target is dispersed into plumes by air flow and mixed with the background odor carried in the air, which together form the odorscape. Insects search and locate the target along the target odor. The behavior of insects can be affected by the shape, composition and concentration of target odors. The background odor plays a complementary or warning role during the target localization of insects. Different background odors can synergize or interfere with the target localization of insects. The insect odorscape is mainly affected by the temperature, humidity, light, heavy metal elements and plant diseases and insect pests in the environment. Studies showed that the olfactory receptors of insects capture odorscape and transmit those odor signals to olfactory nerve centers such as antennal sensilla lobe along the olfactory nerves. Then, the odorscape is analyzed in the nerve centers by the mode of elemental processing or configural processing. The influences of background odor on insect target localization may be the results of the reciprocal addition, competitive binding or signal crosstalk of different odor molecules during the olfactory sensing and coding. At present, several kinds of green pest control technologies have been developed based on the odorscape management, such as insect behavior regulators, exogenous elicitors, breeding the crop varieties that can release resistant volatiles, “push-pull” technology and plant-mediated support system for natural enemies. In the future, it is necessary to further explore the behavioral, electrophysiological and neurological mechanisms of odorscape discrimination in insects, and optimize and integrate the green control technologies related to odorscape management, so as to build rational and efficient odorscape for insect pest control.

 The red imported fire ant, Solenopsis invicta, is a primary invasive pest in China. Currently, scientific researches, control strategies and policy regulations regarding S. invicta mainly focus on the filed of agriculture in China. Although S. invicta is also widely distributed in forests, grasslands, wetlands and urban green spaces and has caused huge damage, the occurrence characteristics and control strategies of S. invicta in these areas are largely overlooked. The occurence of S. invicta is closely associated with human disturbances such as felling, burning and soil turning, and natural factors such as biodiversity, forest canopy density and soil bareness. Due to the low levels of biological diversity and forest canopy density and high levels of human disturbances, there is a high risk of S. invicta invasion in plantation forests and adjacent areas. In natural forests, S. invicta is usually distributed in forest edges and windows, as well as burned areas where the sunlight can directly irradiate. Moreover, nurseries and urban green spaces have a high risk of S. invicta invasion because of large areas of bare soil and high levels of human activities. In areas with high levels of human activities, including plantation forests, nurseries and urban green spaces, S. invicta mainly threatens human health and infrastructure, and directly or indirectly damages trees. In addition, the invasion of S. invicta significantly decreases the abundance and diversity of arthropods in habitats and poses significant threats to wildlife in natural reserves and wetlands. Although it has been reported that S. invicta contributes to promoting seed migration and enhancing soil nutrient circulation under certain conditions, its harmful impacts far exceed its potential beneficial effects. Quarantine, monitoring and control are three important aspects to prevent S. invicta invasion in forestry. Wood, seedlings with soil, and turf are the main objects that may carry S. invicta and need to be quarantined, and fumigation can effectively eliminate S. invicta. Baiting and trapping are the main methods to monitor S. invicta. Recently, some new technologies, including remote sensing and radar technology, also have been developed to monitor S. invicta in grasslands and urban green spaces. Although chemical control is the most predominant control strategy for S. invicta, the use of highly toxic, broad spectrum and hardly degradable insecticides may negatively affect non-target organisms in natural reserves and wetlands. Therefore, it is essential to develop environmentally friendly agents and methods to control S. invicta.

 Unmovable cultural relics are important physical materials that reflect the development of social productivity and social life in the past. They are important research objects for cultural relics, with extremely high historical, artistic and scientific values. Unmovable cultural relics suffer from various deterioration effects for being outdoors. Biodeterioration caused by pests is one of the important reasons for cultural relics damage. Among unmovable cultural relics, ancient buildings, murals and earthen sites are particularly affected by insect pests. According to the classification of cultural relics, we expounded on the main types and mechanisms of insect pests in ancient buildings, murals and earthen sites, and summarized the current methods of pest control in these cultural relics in this article. Physical and chemical control methods are traditionally used to prevent and control pests in cultural relics. The chemical methods are rapid and highly effective ways to kill insects, but chemical agents have brought great pollution to the ecological environment, and the vulnerability of cultural relics restricts the use of chemical insecticides. At present, many long-acting and environment-friendly green insecticides have greatly improved traditional chemical methods. In addition, biological control methods that use biological natural enemies or parasitic organisms to control pests not only have small impacts on the ecosystem but also have a long-lasting effect, which is a hotspot in research on new pest control. However, whether the new species used to control the pests will do harm to cultural relics needs to be further studied. Pest control of cultural relics is a cross-research field, and the methods in architecture, agriculture and other fields have great enlightening significance and reference value. Finally, we discussed and prospected the current situation of common pest control research of unmovable cultural relics, hoping to provide a reference for the research of pest control in cultural relics.

【Aim】 The effects of chronic exposure to the sublethal concentration (LC₂₀) of dinotefuran on the growth and development of Sitobion avenae were studied in order to provide a theoretical basis for the scientific use of dinotefuran to control S. avenae and delaying the development of the resistance to the pesticide and extending the useful life of pesticide. 【Methods】 The LC₂₀ of dinotefuran to the 3rd instar nymphs of S. avenae was determined by using the leaf-dip method andusedforchronic exposure on S.
avenae for 15 generations. The resistance ratio of S. avenae to dinotefuran was determined, the developmental duration, reproduction and survival rates of S. avenae of two successive generations which were raised with wheat seedlings in test tube were recorded, and the body length, body width and body weight of adults of F₀ generation were measured. The differences in the body length, body width, body weight, survival rate, adult longevity and number of offspring produced between lowly resistant strain of various generations and the susceptible strain were analyzed by population specific life table and DPS software. 【Results】 After chronic exposure to LC₂₀ of dinotefuran for 15 generations, the resistance of S. avenae reached low level (6.54-fold). The developmental duration of the 2nd, 3rd and 4th instar nymph of F₀ generation of the lowly resistant strain was significantly longer than that of the susceptible strain, and the body length, body width and body weight of F₀ generation of adults of the lowly resistant strain were significantly increased, but the number of offspring produced per adult and adult longevity of F₀ generation of the lowly resistant strain were significantly reduced or shortened as compared to those of the susceptible strain. The adult survival rate, number of offspring produced per adult and adult longevity of F₁ generation of the lowly resistant strain were significantly reduced, the 2nd instar nymphal duration and nymphal duration of F₁ generation of the lowly resistant strain were significantly shortened as compared to those of the susceptible strain. The net reproductive rate (R₀), intrinsic rate of increase (R_m) and finite rate of increase (λ) of F₀ and F₁ generations of the lowly resistant strain were significantly lower than those of the susceptible strain, while the population doubling time (DT) of F₀ and F₁ generations and the mean generation time (T) of F₁ generation of the lowly resistant strain were significantly prolonged as compared to those of the susceptible strain. 【Conclusion】 Chronic exposure to LC₂₀ of dinotefuran results in the increase in the resistance of S. avenae to dinotefuran and individual size of adults of F₀ generation, while inhibits the longevity and fecundity of F₀ and F₁ generations of S. avenae.
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 Host plants and insects have formed complex defense and counter defense  mechanisms in the long-term co-evolution. In this article, we systematically reviewed the  process and mechanism of the mutual defense in host plant-piercing-sucking insect  interactions. The piercing-sucking insects use specialized needles to suck the sap of the  host plant tissue. Plants sense insect feeding signals through cell membrane surface or  intracellular receptors, and activate plant immunity through signal transduction pathways  such as mitogen-activated protein kinase (MAPK) signaling pathway, plant hormone signaling  pathway, calcium ion signaling pathway, transcription factor regulation, Rop/Rac GTPase  signaling pathway and reactive oxygen species (ROS) pathway. To prevent further insect  feeding, host plants form a strengthened physical barrier and induce the production of  secondary metabolites, anti-nutritional enzymes, anti-digestive enzymes and callose  deposition, and release volatiles and other defense mechanisms. In the process of “gaming ” with host plants, piercing-sucking insects often use secreted salivary components  during the feeding to target plant proteins. By destroying the physical barrier of host  plants, or inhibiting the resistance signal transduction of host plants, or inhibiting the  toxic effect of the host secondary metabolites, or by means of cross-border RNA and  horizontal gene transfer, piercing-sucking insects inhibit the plant defense response and  continue feeding to cause damage. In addition, based on the plant-pathogen interaction  model, and combined with the research advance of the host plant-piercing-sucking insect  interaction, we summarized the development of the interaction model between host plants and  piercing-sucking insects. Since the host plant-insect interaction is sophisticated, a  profound study on the mutual defense processes and molecular mechanisms of the host plant- piercing-sucking insect interaction will not only help deepen the understanding of their  co-evolution, but also help to provide theoretical foundation and references for  developing new approaches and technologies for crop insect pest control.

【Aim】 Blister beetles belonging to the family Meloidae within the order Coleoptera, are a series of resource insects with great medicinal value. The larval oligophagous and specialized feeding on locust eggs severely restricts their artificial rearing and the utilization and development of cantharidin. The larval obsession for food was universally acknowledged and proven by many studies, but we found through our rearing experiences that their feeding specialization gradually decreases during the whole larval stage. 【Methods】We conducted a large-scale rearing experiment and physiological and ecological analyses, determined the larval survival rate, pupation rate, adult eclosion rate, dry weight of mature larvae, growth amount, larval growth rate, larval duration, pupal duration, and number of eggs laid per female of Hycleus cichorii from various treatment groups (substituting locust eggs by the artificial diet from the 1st, 2nd, 3rd and 4th instars, i.e. 1st-4th instar groups, respectively) and the control group (fed with locust eggs throughout the larval stage), then compared the growth, development and adult reproduction of grouped meloids to verify the feeding adaptation of H. cichorii larvae to the non-preferred food and figure out the adaptive pattern to the nutritional stress. 【Results】After substituting locust eggs by the artificial diet, the 1st instar group had a significantly lower survival rate than the 2nd, 3rd and 4th instar groups and the control group, and a zero pupation rate. Moreover, after substituting locust eggs by the artificial diet, the 1st instar group had significantly lower larval growth rate and dry weight of mature larvae, and longer larval duration than the 2nd, 3rd and 4th instar groups and the control group. There was no significant difference in the survival rate among the 2nd, 3rd and 4th instar groups, but the pupation rate and adult eclosion rate gradually increased with instars increasing. After substituting locust eggs by the artificial diet, the larval growth rate and dry weight of mature larvae increased, and the larval duration shortened with instars increasing. 【Conclusion】 The results of this study suggest that the 1st instar larvae of H. cichorii can not adapt to the non-preferred food, while the older instar larvae manifest a stepwise improving feeding adaptation with instars. This study demonstrates that the food specialist H. cichorii larvae possess a staged adaptation to nutritional stress. The detailed pattern of changing feeding adaptability provides theoretical feasibility for the complete artificial rearing of H. cichorii larvae and will contribute to the studies on the artificial rearing and resource utilization of medicinal meloids.

【Aim】To identify and analyze the genes and full-length transcripts of  serine/threonine protein kinases of Apis mellifera ligustica using previously gained  high-quality long-read nanopore sequencing data, and to provide reference information and  bases for further functional study.【Methods】Based on the previously obtained  high-quality long-read nanopore sequencing data of A. m. ligustica, the genes and  full-length transcripts of serine/threonine protein kinases were screened from the Nr  database by Blast. The screened full-length transcripts of serine/threonine protein kinases  were compared with the annotated transcripts in the reference genome of A. mellifera  (Amel_HAv3.1) using gffcompare software to identify the unannotated new genes and new  transcripts. The types of alternative splicing (AS) events occurring in serine/threonine  protein kinase genes were identified using Astalavista software. Visualization of the  structure of spliceosomes was performed with IGV browser. RT-PCR was employed to confirm  the authenticity of randomly selected six AS events.【Results】In total, 71 genes and 335  full-length transcripts of serine/threonine protein kinases of A. m. ligustica were  identified, and one new gene and 97 new transcripts were discovered. The structure of 14  annotated genes was optimized, and the 5′ends of six genes and the 3′ends of eight genes  were prolonged, respectively. A total of 57 AS events were identified in seven genes of  serine/threonine protein kinases in A. m. ligustica, including 40 exon skipping (ES) events,  15 alternative 5′splicing site (A5SS) events and two alternative 3′splicing site (A3SS)  events. RT-PCR results of randomly selected six AS events indicated that all of the target  fragments were in accordance with the expected sizes, confirming the authenticity of AS  events.【Conclusion】 Genes and full-length transcripts of serine/threonine protein kinases  of A. m. ligustica were systematically identified and the structure of the serine/threonine  protein kinase genes annotated in A. mellifera reference genome was optimized in this  study.

【Aim】 To explore the effects of the heavy metal Cu²⁺ and the pesticide  avermectin and their combined stress on the growth and development and reproductive  behavior of the Asian corn borer, Ostrinia furnacalis in farmland.【Methods】 We added 50  mg/kg of Cu²⁺ and 0.039 mg/L of avermectin (LC₁₀ concentration against the 3rd instar  larvae of O. furnacalis) to the artificial diet, respectively, and simultaneously, and then  got three kinds of treated diets containing Cu²⁺ (Cu), avermectin (Av) and both (Av+Cu), 
taking the normal artificial diet as the blank control group. We fed the neonate larvae of  O. furnacalis with the four diets under laboratory conditions, and systematically  investigated and recorded the parameters of growth and development (larval duration, pupal 
duration, pupal weight, adult weight, growth rate, adult emergence rate and adult  longevity)， calling behavior (calling rate and average calling duration), orientation  behavior (take-off rate, orientation rate, average response time, flying halfway rate and  landing to pheromone source rate), and reproduction (number of eggs laid per female and egg  hatching rate).【Results】 Cu, Av and their combined stress (Av+Cu) had certain effects on  the growth and development and reproduction of O. furnacalis. On the one hand, the  postembryonic developmental duration (larval plus pupal duration) of female and male O.  furnacalis in Cu treatment alone was significantly shortened as compared to  that in the  blank control group. After Av treatment alone, the postembryonic developmental duration of  female and male O. furnacalis was significantly prolonged to 38.31 and 38.95 d,  respectively, being 67.07% and 67.38% longer than that of the blank control group,  respectively. After Cu treatment alone, the body weight of female pupae, male pupae, female  adults and male adults of O. furnacalis decreased significantly, being 13.16%, 6.45%,  7.13% and 4.60% lower than that of the blank control group, respectively. Then after Av  treatment alone, the body weight of female pupae, male pupae and female adults of O.  furnacalis decreased significantly, being 26.50%, 8.96% and 12.46% lower than that of the  blank control group, respectively, while the body weight of male adults was significantly  higher than that of the blank control group by 6.05%. At the same time, Cu treatment had a  certain impact on the calling behavior of female adults. After Cu treatment, the highest  calling rate and average calling duration in each scotophase decreased with the scotophase,  while those in the blank control group showed a trend of increasing first and then  decreasing with the scotophase. After Av treatment, the calling behavior of female adults  was promoted: the highest calling rates in all scotophases except the scotophase 5 (the 5th  scotophase after emergence of females) reached 100%; the average calling duration in Av  treatment groups was significantly longer than that in the blank control groups in all  scotophases except the scotophase 3 (the 3rd scotophase after emergence of females), and  the average calling duration in Av treatment group was the highest (5.71 h) in scotophase  5. Compared to the blank control group, Cu and Av treatment alone significantly inhibited  the orientation behavior of male adults and the number of eggs laid per female of O.  furnacalis. On the other hand, the effects of the combined stress of Av and Cu and their  single stresses were different. Compared to the blank control group, Av+Cu treatment  inhibited the growth and development of O. furnacalis, causing significant extension of the  developmental duration and body weight loss. The female and female postembryonic  developmental duration in Av+Cu treatment was 37.60 and 37.04 d, respectively, only shorter  than that in Av treatment. The body weight of female and male pupae and female adults in  the Av+Cu treatment group was the lowest, significantly lower than that in the blank  control group. In the mating combinations of female and male adults stressed by Av+Cu and  female and male adults in the blank control group, the landing to pheromone source rate of  male adults and the number of eggs laid per female were significantly lower than those of  the mating combination of female and male adults in the blank control group, and both were  the lowest. The calling behavior of female adults of O. furnacalis after Av+Cu stress was  relatively consistent with that after Av treatment, and the highest calling rates in all  scotophases reached 100%. The average calling duration in each scotophase in Av+Cu  treatment group was significantly longer than that in the blank control group and Cu  treatment group, and showed no significant difference from that in Av treatment group, and  the average calling duration in Av+Cu treatment was the longest (6.16 h) in scotophase 3.【 Conclusion】Single and combined stresses of Cu and Av inhibit the growth and development,  disturb the reproductive behavior of adults and reduce the fecundity of O. furnacalis.  Among the effects of the combined stress of Cu and Av on O.furnacalis, Av plays a leading  role.

【Aim】 To analyze the differences in the midgut bacterial composition among different varieties of Bombyx mori with different vitalities and cocoon shell ratios, and their effects on the related traits such as vitality and cocoon shell ratio. 【Methods】 Based on the results of the long-term feeding survey on B. mori resource, the variety 932G with high vitality and the variety 2041J with high silk yield were selected as experimental materials, the midguts of the 5th instar larva and pupa were collected, and the 16S rDNA sequences of the midgut bacteria were sequenced and analyzed by the high-throughput sequencing platform to compare the differences in the composition and function of the midgut bacteria between different varieties and different developmental stages of B. mori. 【Results】 A total of 399 and 453 operational taxonomic units (OTUs) of the midgut bacteria were obtained from 932G and 2041J at the 5th instar larval stage, and 138 and 162 OTUs of the midgut bacteria were obtained from 932G and 2041J at the pupal stage, respectively. The dominant phyla of the midgut bacteria of B. mori at the 5th instar larval stage were Proteobacteria, Firmicutes and Actinobacteriota, and the dominant genus was Methylobacterium with the highest abundance, followed by Staphylococcus. However, there were significant differences in the relative abundance of some genera between the two varieties. The relative abundance of some genera including Devosia, Ralstonia, Nitrospira, Brachybacterium, Rothia, Lawsonella etc. in the midgut of the 5th instar larva of 932G was significantly higher than that in the midgut of the 5th instar larva of 2041J. The relative abundance of Pseudomonas, Methylobacterium, Acinetobscter, Cloacibacterium, Leuconostoc, Propionibacteriaceae, Psychrobacter, Sphingobium, Bacteroides etc. in the midgut of the 5th instar larva of 2041J was significantly higher than that in the midgut of the 5th instar larva of 932G. There were 77% and 78% functional genes in the midgut bacteria of the 5th instar larvae of 932G and 2041J enriched on the metabolic pathways of KEGG, respectively, followed by those of the function genes enriched on the environmental information processing and genetic information processing. The proportions of the midgut bacterial communities involved in nitrate reduction, nitrogen respiration, nitrate respiration, nitrite respiration and nitrogen fixation in the 5th instar larva of 932G were higher than those in 2041J. The proportions of the midgut bacterial communities involved in chemical heterotrophic, urea decomposition and methanol oxidation in the 5th instar larva of 2041J were higher than those in the 5th instar larva of 932G. The difference in the midgut bacterial composition between the 5th instar larva and pupa was significant. Erwinia of Proteobacteria in the midgut of the pupa was the dominant genus, and there was no significant difference in the relative abundance of Erwinia between the two varieties at the pupal stage. The relative abundance of functional genes involved in amino acid transport and metabolism, extracellular secretion and transport, carbohydrate transport and metabolism, and inorganic salt transport and metabolism of the midgut bacteria in the pupa was significantly higher than that in the 5th instar larva of 932G.【Conclusion】 There were significant differences in the midgut bacterial composition and predicted function between the varieties 932G with high vitality and 2041J with high silk yield of B. mori at the 5th instar larval stage. The composition and function of the midgut bacteria of B. mori at the pupal stage were significantly different from those of B. mori at the 5th instar larval stage, and there was no significant difference in the relative abundance of midgut bacteria between the two varieties at the pupal stage. These research results can provide a reference for further exploring the role of gut microorganisms in stress resistance, drug resistance, disease resistance, protein synthesis and transformation of B. mori and variety breeding.

【Aim】To observe the ovarian developmental progress and formulate ovarian developmental grading criteria of Conopomorpha sinensis, explore the influence of mating on the ovarian developmental progress and fecundity. 【Methods】 The newly eclosed female and male adults of C. sinensis were paired in a 1∶1 ratio and reared. The female ovaries were dissected daily, and the mating experience was judged according to the characteristics of the bursa copulatrix. The characteristics of fat body, length of ovarioles, total number of egg chambers and number of mature eggs of mated and unmated females were recorded for grading the ovarian development progress. The newly eclosed female and male adults paired in a 1∶1 ratio, and newly eclosed female adults that were individually reared were used as the mated group and unmated group, respectively, and the pre-oviposition period, oviposition period, number of eggs laid per female and female adult longevity were counted in the two groups.【Results】 The ovarian development of C. sinensis could be divided into five stages, including yolk deposition prophase (stage Ⅰ), yolk deposition phase (stage Ⅱ), egg maturation phase (stage Ⅲ), peak phase of oviposition (stage Ⅳ) and terminal phase of oviposition (stage Ⅴ). Only the ovaries of the mated female adults could completely develop. Otherwise, the ovaries of the unmated female adults only developed into the yolk deposition phase (stage Ⅱ). The preoviposition period, oviposition period, number of eggs laid per female and female adult longevity in the mated group were 3.82 d, 11.23 d, 176.42 grains and 16.35 d, respectively. The female adults in the unmated group could not lay eggs for life, and the female adult longevity in the unmated group was 20.48 d. 【Conclusion】 The ovarian development of C. sinensis adults can be divided into five stages. However, mating is a prerequisite for the completion of ovarian development of the female adult. The ovarian development of the unmated female adults terminates after reaching stage Ⅱ. The fecundity of the mated female adults is significantly higher than that of the unmated females, and the unmated females can not lay any eggs for life.

【Aim】To elucidate the function of Niemann-Pick type C2 protein of Varroa destructor (VdesNPC2b) in host recognition by analyzing the binding properties and mechanisms of VdesNPC2b with the larval pheromones methyl oleate and β-ocimene of the host bees of V. destructor, so as to provide a theoretical basis for biological control of V. destructor. 【Methods】 The open reading frame (ORF) of VdesNPC2b was amplified and analyzed using bioinformatics. The prokaryotic expression vector was constructed based on pET-30a plasmid. The recombinant VdesNPC2b protein was obtained by prokaryotic expression and affinity column chromatography. The binding capacities of VdesNPC2b with the larval pheromones of bees methyl oleate and β-ocimene were analyzed by fluorescence competitive binding experiment, and the binding mechanism of them was analyzed by measuring the binding capacity change at two different temperatures (22 and 32 ℃) through fluorescence spectrum temperature variation experiment. The homologous modeling of VdesNPC2b was performed by SWISS-MODEL software, and the molecular docking simulation of VdesNPC2b and β-ocimene was performed by MVD to preliminarily analyze the key amino acid sites in the binding of VdesNPC2b and β-ocimene. 【Results】 The ORF of VdesNPC2b (GenBank no.: OR463903) is 531 bp in full-length, encoding 176 amino acids. VdesNPC2b has a signal peptide of 16 amino acid residues at the N-terminus. The fluorescent competitive binding assay result showed that the dissociation constant K _D values of VdesNPC2b with methyl oleate and βocimene were 2.89 and 3.49 μmol/L, respectively, with the binding process of dynamic quenching, and the main driving forces maintaining the interaction between VdesNPC2b and methyl oleate and β-ocimene was hydrophobic force. Homologous modeling showed that the secondary structure of VdesNPC2b is β-sheet, and forms a potential external cavity. Leu68, Ile103 and Phe107 could be the key amino acid sites to maintain a stable form of the binding of VdesNPC2b and β-ocimene. 【Conclusion】 V. destructor may use VdesNPC2b binding long-chain brood ester pheromone methyl oleate and volatile β-ocimene to locate and identify host honey bee.

【Aim】 This study aims to clarify the expression pattern of odorant binding protein 1 (OBP1) in Aethina tumida and analyze the role of AtOBP1 in olfactory recognition of A. tumida.【Methods】 The cDNA full-length sequence of AtOBP1 was cloned based on the transcriptome and genome database of A. tumida and analyzed by bioinformatics. RT-qPCR was used to detect the expression levels of AtOBP1 in different developmental stages (egg, larva, pupa, female adult and male adult), different tissues (head, cuticle, wing, leg, fat body, gut, Malpighian tubules, testis and ovary) of the 7-day-old adult and in the head of different day-old adults of A. tumida after eclosion. The biological function of AtOBP1 in olfactory recognition of A. tumida was studied by RNA interference (RNAi) and Y-tube behavior choice experiment. 【Results】The cDNA full-length sequence of AtOBP1 gene (GenBank accession no.: MT211982.1) has six exons and an open reading frame (ORF) of 447 bp in length. AtOBP1 encodes 148 amino acid residues with PBP_GOBP superfamily conserved domain, and the predicted molecular mass and isoelectric point are 15.9 kD and 4.73, respectively. AtOBP1 protein is a dimer composed of six α-helics with six conserved cysteines that form three disulfide bonds. The phylogenetic tree also showed that AtOBP1 was closely clustered into one branch with TmOBP8 from Tenebrio molitor of Coleoptera. The RT-qPCR results showed that AtOBP1 was highly expressed in the pupal stage and the male adult stage, and was highly specifically expressed in the head and testis of adults. In addition, the expression level of AtOBP1 in adult head increased gradually with the day-old age, reached two peaks in the 5- and 7-day-old adult stages, respectively, and decreased in the 8-day-old adult stage. RNAi in combination with Y-tube behavior choice experiment results revealed that silencing of AtOBP1 resulted in significantly reduced preference of A. tumida adults to the pollen volatile compounds ethyl palmitate and ethyl linolenate.【Conclusion】AtOBP1 belongs to Classical OBPs family. AtOBP1 is mainly expressed in the head and testis of A. tumida adults, and may participate in the recognition process of the pollen volatile compounds ethyl palmitate and ethyl linolenate in A. tumida.
Key words: Aethina tumida; odorant binding protein; AtOBP1; RNAi; olfactory behavior

【Aim】The purpose of this study is to explore whether glutamate-gated chloride channels (GluCls) of the beet armyworm, Spodoptera exigua (SeGluCls) encoded by different transcription variants of SeGluCl have different susceptibilities to insecticides using CRISPR/Cas9 gene editing technology. 【Methods】 The full-length cDNA sequence of SeGluCl from S. exigua was obtained using RT-PCR and RACE, and analyzed by bioinformatics. Two splicing variants SeGluCl 3a and SeGluCl 3b of SeGluCl were knocked out by CRISPR/Cas9 gene editing technique, and two knockout strains (3a-KO and 3b-KO) of S. exigua were established. The difference in the susceptibilies of the 3rd instar larvae of the susceptible strain WH-S (control strain) and 3a-KO and 3b-KO strains to three insecticides abamectin, emamectin benzoate and fipronil was determined by bioassay. 【Results】 The full-length cDNA sequence of SeGluCl of S. exigua was obtained, and its two splicing variants (SeGluCl 3a and SeGluCl 3b) were found. The open reading frame (ORF) of SeGluCl 3a (GenBank accession no.: OM304353) is 1 362 bp in length encoding 454 amino acids. The ORF of SeGluCl 3b (GenBank accession no.: OM304354) is 1 365 bp in length encoding 455 amino acids. The two SeGluCls encoded by the splicing variants SeGluCl 3a and SeGluCl 3b contain four transmembrane regions and one cysteine loop. Phylogenetic analysis indicated that SeGluCl was most closely related to GluCls of S. litura and S. frugiperda. Compared to the control strain WH-S, the knockout strains (3a-KO and 3b-KO) showed no significant difference in the susceptibilities to abamectin, emamectin benzoate and fipronil. 【Conclusion】 There is no difference in the susceptibility of SeGluCls encoded by the splicing variants SeGluCl 3a and SeGluCl 3b of SeGluCl to the three insecticides abamectin, emamectin benzoate and fipronil in S. exigua.

【Aim】 This study aims to elucidate the molecular characters of chitin synthase  (CHS) gene in Apis mellifera and uncover the function of CHS in immune response of A.  mellifera worker larvae to Ascosphaera apis stress. 【Methods】 The molecular characters,
conserved motifs and structural domains of the A. mellifera CHS protein were predicted and  analyzed using relevant bioinformatics software. Phylogenetic analysis of amino acid  sequences of CHS proteins in A. mellifera and other insects was performed with MEGA X  software. The dsRNAs of CHS and egfp were synthesized via in vitro transcription method,  and fed to the A. apis-stressed 3-day-old larvae of A. mellifera workers to perform  RNAi. RT-qPCR was used to determine the expression levels of CHS and immune-related genes  abaecin, apidaecin, birc5, defensin-1 and PGRP-S2 in the 5-day-old larval gut of A.  mellifera workers in response to A. apis stress. 【Results】 The CHS protein of A.  mellifera contains 1 572 amino acids belonging to 20 types of amino acids, among which the  numbers of amino acids with positive and negative charge are 177 and 169, respectively. CHS  has the molecular weight of 178.77 kD, isoelectric point of 6.65 and cellulose synthase  CESA3 catalytic structural domain. Three motifs (Motif 1, Motif 2 and Motif 3) and two  structural domains (Chitin_synth_2 and Glyco_trans_2_3) were identified in CHSs in 13  insect species such as A. mellifera and A. cerana. Phylogenetic tree showed that the CHSs  in A. mellifera and A. cerana of Hymenoptera showed the highest amino acid sequence  identities, and clustered into one branch with the bootstrap value of 100. The expression  level of CHS in the 5-day-old larval gut of A. mellifera in the dsCHS-fed group was  significantly down-regulated as compared to that in the dsegfp-fed control group, with  the interference efficiency of 29.40%. In the dsCHS-fed group, the expression levels of  abaecin, birc5 and defensin-1 in the 5-day-old larval gut of A. mellifera were extremely  significantly up-regulated, that of PGRP-S2 was significantly up-regulated, while that  of apidaecin was extremely significantly down-regulated, as compared with those in the d segfp-fed control groups. 【Conclusion】 A. mellifera CHS may be an intracellular  hydrophilic transmembrane protein. The amino acid sequences of CHSs in A. mellifera and  other insects are highly conservative, and those in A. mellifera and A. cerana are the most  highly conservative. CHS affects A. mellifera worker larval immune response to A. apis  stress.

【Aim】 The objective of this study is to unravel the regulatory role of ame-miR-14 in the developmental process of the larval guts of Apis mellifera ligustica workers.【Methods】 The expression and sequence authenticity of ame-miR-14 in the 6-day-old larval guts of A. m. ligustica workers were proved by Stem-loop RT-PCR and Sanger sequencing, respectively. Overexpression and knockdown of ame-miR-14 were conducted by feeding its corresponding mimic (mimic-ame-miR-14) and inhibitor (inhibitor-ame-miR-14), and their corresponding negative controls mimic-NC and inhibitor-NC, respectively, and then RT-qPCR was used to detect the expression levels of ame-miR-14 in the 4-6-day-old larval guts of A. m. ligustica workers. Bioinformatic software was used to predict and analyze the target genes of ame-miR-14. RT-qPCR was employed to detect the relative expression levels of the target genes FoxO and Hedgehog in the 4-6-day-old larval guts after overexpression and knockdown of ame-miR-14.【Results】 ame-miR-14 truly exists and is expressed in the 6-day-old larval guts of A. m. ligustica workers. The expression levels of ame-miR-14 in the 4-6-day-old larval guts of A. m. ligustica workers fed with mimic-ame-miR-14 were significantly up-regulated as compared to those fed with mimic-NC. The expression levels of ame-miR-14 in the 4-6-day-old larval guts of A. m. ligustica workers fed with inhibitor-ame-miR-14 were significantly down-regulated as compared to those fed with inhibitor-NC. In total, ame-miR-14 can target 309 genes, which could be annotated to 45 KEGG pathways and 36 GO terms. Further analysis showed that ame-miR-14 can target 14 genes associated with growth and development and have potential targeting relationship with target genes FoxO and Hedgehog. After overexpression of ame-miR-14, the expression level of FoxO in the 4dayold larval gut of the mimic-ame-miR-14 group was down-regulated and those in the 5- and 6-day-old larval guts significantly down-regulated as compared to those in the mimic-NC group. After knockdown of ame-miR-14, the expression level of FoxO in the 4-day-old larval gut of the inhibitor-ame-miR-14 group was down-regulated, while that in the 5-day-old larval gut was significantly up-regulated and that in the 6-day-old larval gut was up-regulated as compared to those in the inhibitor-NC group. After overexpression of ame-miR-14, the expression levels of Hedgehog in the 4-6-day-old larval guts of the mimic-ame-miR-14 group were significantly down-regulated in comparison with those in the mimic-NC group, whereas those in the 4-6-day-old larval guts of the inhibitor-ame-miR-14 group were up-regulated in comparison with those in the inhibitor-NC group. 【Conclusion】ame-miR-14 truly exists and is expressed in the larval guts of A. m. ligustica workers. Effective overexpression and knockdown of ame-miR-14 in the larval guts of A. m. ligustica workers can be achieved by feeding mimic and inhibitor, respectively. ame-miR-14 potentially participates in regulation of the larval gut development by negatively regulating the expression of FoxO and Hedgehog.

 Sex determination is an outstanding question in developmental and evolutionary biology. The sex determination cascade in most of known insects is: primary signaling element→key gene of sex determination→double switch gene→sex differentiation gene. In spite of this pattern, different insects have different sex determination genes and regulatory mechanisms, especially the primary signaling element of sex determination. Since the primary signal of Drosophila melanogaster was discovered, the primary signal of mosquito, bee, wasp (Nasonia vitripennis), silkworm (Bombyx mori) and other model insects has been determined successively. There are many kinds of primary signals, including the dose of sex chromosomes, male-determining factors (M factors), heterozygosity of alleles and maternal imprinting, which make it more difficult to study non-model insects to some extent. Even so, the downstream regulatory mechanism is relatively conserved. In particular, the transformer (tra)+transformer2 (tra2)→doublesex (dsx)/fruitless (fru) pathway is fairly common in most insects. Tra produces alternative splicing by sensing primary signals, and with the help of tra2, tra regulates the splicing of itself and the downstream dsx and fru, and maintains gender development. Acting as the terminal ‘double-switch’, dsx is the most conserved gene in the insect sex determination cascade. dsx is highly conserved in regulating bisexual development, courtship behavior, genitalia and formation of sexual dimorphism. As a switch gene of Drosophila sexual behavior, fru is involved in regulating almost all male sexual behaviors of Drosophila. Its function has been verified in a variety of insects such as Bactrocera dorsalis, Aedes aegypti and B. mori, and it has become a typical gene for understanding the complex sexual behavior of insects. Understanding the sex determination cascade in insects, and clarifying the function and interaction of each sex determination gene are essential to elucidate the mechanism of sex determination. It provides a theoretical basis for revealing the general law of insect sex determination, and promoting the basic research on the upstream regulatory mechanism of insect sex determination, and realizing the genetic manipulation of insect sex determination.

 【Aim】The aim of this study is to find out the reference genes stably expressed in different developmental stages and adult tissues of Grapolita molesta and in its adults after treatment with different concentrations of three insecticides, so as to lay a foundation for the subsequent study on target gene expression in G. molesta.【Methods】Ten candidate reference genes (β-actin, 18S rRNA, β-tubulin, EF-1α, RPL13, RPL32, RSPL40, UBC7, α-tubulin and RPS20) were selected based on G. molesta transcriptome data. The expression levels of the candidate reference genes in different developmental stages (egg, 1st-5th instar larvae, pupa and adult) and different adult tissues (head, foregut, midgut, hindgut, fat body, Malpighian tubules, testis and ovary) of G. molesta and in G. molesta adults treated with three insecticides at different concentrations (avermectin: 19.819, 72.897 and 179.663 μg/mL; imidacloprid: 17.638, 163.323 and 762.986 μg/mL; and lambda-cyhalothrin: 33.791, 96.123 and 198.282 μg/mL) with the method of residual film in glass tube were detected using real-time quantitative PCR (qRT-PCR). The expression stabilities of the 10 candidate reference genes were evaluated by geNorm, NormFinder, ΔCt, BestKeeper and RefFinder. The cytochrome P450 gene CYP354A32 of G. molesta was selected for validation. 【Results】 qRT-PCR results combined with software evaluation results revealed that the expression stabilities of the reference genes in different developmental stages of G. molesta were ranked in a descending order of β-tubulin, 18S rRNA, EF-1α, RPL13, β-actin, RPS20, UBC7, RPL32, α-tubulin and RSPL40, those in different adult tissues were ranked in a descending order of UBC7, β-tubulin, β-actin, 18S rRNA, RSPL40, EF-1α, RPS20, RPL13, RPL32 and α-tubulin, and those in adults after exposure to different concentrations of avermectin, imidacloprid and lambda-cyhalothrin were ranked in a descending order of RPS20, RPL13, β-tubulin, β-actin, RPL32, RSPL40, EF-1α, UBC7, α-tubulin and 18S rRNA. The expression characteristics of CYP354A2 analyzed by using the obtained reference gene combinations showed that CYP354A2 was highly expressed in the old larvae and adults when using the combination of β-tubulin, EF-1α and 18S rRNA as the reference genes, and was highly expressed in the testis and ovary of adults when using the combination of UBC7, β-tubulin and β-actin as the reference genes. After G. molesta adults were exposed to different concentrations of insecticides, only the expression level of CYP354A2 in the treatment with 19.819 μg/mL avermectin was higher than that in the control, while the expression levels of CYP354A2 in treatments with other concentrations of insecticides were lower than that in the control when using the combination of RPS20, RPLB and β-tubulin as the refernece genes.【Conclusion】 The combination of β-tubulin, 18S rRNA and EF-1α is recommended as the reference genes for studying the target gene expression in different developmental stages of G. molesta, that of UBC7, β-tubulin and β-actin as the reference genes for studying the target gene expression in different adult tissues of G. molesta and that of RPS20, RPL13 and β-tubulin as the reference genes for studying the target gene expression in adults of G. molesta after treatment with different concentrations of avermectin, imidacloprid and lambda-cyhalothrin.

【Aim】 To clarify the defense mechanism of Ostrinia furnacalis against cadmium and chlorantraniliprole, and to evaluate the cumulative effects of heavy metals and pesticide pollution on insects. 【Methods】 The newly hatched larvae of O. furnacalis were fed with the artificial diet containing 5 mg/kg cadmium, 0.003 mg/kg chlorantraniliprole and 5 mg/kg cadmium+0.003 mg/kg chlorantraniliprole, respectively, and those fed with the normal artificial diet were used as the control. The developmental duration, body weight, adult emergence rate and abnormal pupal rate were recorded, and the activities of detoxification enzymes including glutathione-S-transferase (GST), carboxylesterase (CarE) and acetylcholinesterase (AChE) in O. furnacalis at different developmental stages (3rd instar larva, female and male pupae, and female and male adults) were detected. 【Results】 Cadmium (5 mg/kg), chlorantraniliprole (0.003 mg/kg), and their combined treatment (5 mg/kg cadmium+0.003 mg/kg chlorantraniliprole) had effects on the growth and development of O. furnacalis. In chlorantraniliprole treatment group, the larval duration of O. furnacalis was the longest, significantly prolonged by 7.1 d as compared to that in the control group, and the pupal weight, adult weight and adult emergence rate of O. furnacalis were the lowest, significantly decreased by 9.1 mg, 2.4 mg and 25.5% as compared with those in the control group. In cadmium+chlorantraniliprole treatment group, the larval duration of O. furnacalis was 4.9 d shorter than that in chlorantraniliprole treatment group, and the abnormal pupal rate was the highest, significantly increased by 19.4% as compared to that in the control group. The adult duration of O. furnacalis in cadmium+chlorantraniliprole treatment group was the shortest, significantly reduced by 1.6 d as compared to that in the control group. Cadmium, chlorantraniliprole and cadmium+chlorantraniliprole had effects on the detoxification enzyme activities in O. furnacalis. Compared with the control, cadmium, chlorantraniliprole and cadmium+chlorantraniliprole showed inducing effects on the GST activities in the 3rd instar larvae, female and male pupae and male adults of O. furnacalis, and the GST activities in different developmental stages of O. furnacalis in cadmium+chlorantraniliprole treatment group were significantly higher than those in the other treatment groups and the control group. Compared with the control, cadmium, chlorantraniliprole and cadmium+chlorantraniliprole showed inhibitory effects on the CarE activities in different developmental stages of O. furnacalis, and the cadmium+chlorantraniliprole treatment had the strongest inhibitory effect on the CarE activities in various developmental stages of O. furnacalis. Compared with the control, cadmium, chlorantraniliprole and cadmium+chlorantraniliprole showed inducing effects on the AChE activity in the 3rd instar larvae of O. furnacalis, but had different effects on the AChE activities in the pupae and adults. 【Conclusion】 Cadmium (5 mg/kg), chlorantraniliprole (0.003 mg/kg) and their combined treatment can all affect the growth and development of O. furnacalis, and have different effects on its detoxification enzyme activities.

【Aim】The purpose of this study is to investigate the cross-generational  effects of different concentrations of thiamethoxam on Riptortus pedestris populations.  【Methods】The 3rd instar nymphs of R. pedestris were fed with the soybean seeds treated  with different concentrations of thiamethoxam ［LC₁₀(5.2 mg/L), LC₂₀(11.2 mg/L), LC₃₀(19.6  mg/L), LC₄₀(31.6 mg/L) and LC₅₀(49.4 mg/L)］ by liquid-dipping method for 24 h. The  surviving nymphs were reared until the adults emerged and continued to breed to establish  the F1 populations. The growth, development and reproduction of the F1 population were  systematically recorded. And the biological parameters of the F1 population were analyzed  using the age-stage two-sex life table. 【Results】After the 3rd instar nymphs of R.  pedestris were fed with the soybean seeds exposed to different concentrations of  thiamethoxam, the developmental duration and pre-oviposition period of the F1 population  of R. pedestris were prolonged. The egg duration and nymphal duration in the treatment with  LC₅₀ of thiamethoxam were the longest, being prolonged by 1.01 and 8.39 d, respectively,  and the pre-oviposition period in the treatment with LC₂₀ of thiamethoxam was the longest,  being prolonged by 3.54 d, as compared to those in the control (clear water). Thiamethoxam  treatment shortened the longevity of adult females and males to some degree, which was  reduced by 6.89 and 8.94 d, respectively, in the treatment with LC₅₀ of thiamethoxam, as  compared to that in the control. Compared to the control, thiamethoxam treatment resulted  in the decrease in the age-stage specific survival rate, number of eggs laid per female,  intrinsic rate of increase r_m, finite rate of increase λ, net reproductive rate R₀ and  population trend index I of the F1 population of R. pedestris with increasing thiamethoxam  concentration, while caused the prolonged mean generation time T. Compared to the control,  treatment with LC₄₀ of thiamethoxam caused the maximum reduction in the number of eggs laid  per female, which were decreased by 30.37%, and treatment with LC₅₀ of thiamethoxam  resulted in the maximum reduction in the intrinsic rate of increase r_m， finite rate of  increase λ, net reproductive rate R₀ and population trend index I, which were decreased by  150.40%, 1.88%， 55.92% and 65.07%, respectively, and caused the longest mean generation  time T, which was prolonged by 8.4679 d. 【Conclusion】The growth, development and  reproduction of the F1 population of R. pedestris are still inhibited by thiamethoxam  treatment to the nymphs, and the inhibitory effects increase with increasing thiamethoxam  concentration. The control efficacy of thiamethoxam against R. pedestris shows  cross-generational effects.

【Aim】 Climate change and overgrazing are seriously threatening the functions of  alpine meadows on the Qinghai-Tibetan Plateau, southwestern China. Theoretically, large  herbivore grazing is tightly related to the boveground arthropod diversity, while this  relationship remains unclear. 【Methods】 Yak (Bos grunniens), as a typical native  livestock on the Qinghai-Tibetan Plateau, was used as animals to conduct grazing  experiment in alpine meadows. Four grazing intensities (heavy grazing: 3 yaks/hm²; moderate  grazing: 2 yaks/hm²; light grazing: 1 yak/hm2; and no-grazing) were set and metabarcoding  technology combined with traditional plant quadrat survey was used to examine the effects  of grazing intensity on the α diversity (Simpson, Chao1, ACE, and Shannon-Wiener),  relative abundance and β diversity of aboveground arthropods, the α diversity  (Shannon-Wiener diversity index, species richness and Pielou’s evenness index) of plant  communities, and the relationships between the α diversity of aboveground arthropods and  the α diversity of plant communities. 【Results】 The results showed that the α diversity  of aboveground arthropods in alpine meadows did not differ significantly among different  grazing intensities, while moderate grazing tended to increase the arthropod diversity. The  dominant order of aboveground arthropods under different grazing intensities was the  Orthoptera, with the relative abundance of 97.30%, 81.93%, 94.29% and 67.60%, respectively,  under no-grazing, light grazing, moderate grazing and heavy grazing. Grazing increased the  relative abundance of the Hemiptera and Diptera. The community structures of aboveground  arthropods under no-grazing and moderate grazing showed slight difference, but those under  light grazing and heavy grazing obviously differed. There was no significant correlation  between aboveground arthropod diversity and plant community diversity. 【Conclusion】 This  study suggest that yak grazing intensity has no significant effect on aboveground arthropod  diversity in alpine meadows, but obviously alters the relative abundance of the dominant  species and community structures of aboveground arthropods. Moderate grazing might be the  optimal grazing intensity to protect aboveground arthropod diversity. This study, to a  certain extent, provides theoretical supports for the maintenance and protection of  biodiversity in alpine meadows.

【Aim】 To reveal the role of the superoxide dismutase genes in Liposcelis bostrychophila in response to high and low temperature stresses. 【Methods】The cDNAs of three superoxide dismutase genes Cu/Zn-SOD1, Cu/Zn-SOD2 and Fe/Mn-SOD of L. bostrychophila were cloned by RT-PCR, and their sequence characteristics were analyzed by bioinformatics methods. RT-qPCR was used to detect the relative expression levels of Cu/Zn-SOD1, Cu/Zn-SOD2 and Fe/Mn-SOD in adults at 0, 1 and 2 h under high temperature (42 ℃) and low temperature (4 ℃) stresses. 【Results】 LbCu/Zn-SOD1, LbCu/Zn-SOD2 and LbFe/Mn-SOD (GenBank accession numbers are OQ938782, OQ938783 and OQ938784, respectively) of L. bostrychophila were cloned, with the open reading frames (ORFs) of 465, 630 and 636 bp in length, encoding 154, 209 and 211 amino acids with the relative molecular weights of 15.85, 22.33 and 23.72 kD, and the isoelectric points of 6.17, 7.68 and 6.79, respectively. LbCu/Zn-SOD1 and LbCu/Zn-SOD2 had one and two Cu/Zn superoxide dismutase signatures, respectively. LbFe/Mn-SOD had one Fe/Mn superoxide dismutase signature. The results of phylogenetic analysis showed that Cu/Zn-SOD1, Cu/Zn-SOD2 and Fe/Mn-SOD were highly conserved in insects. The expression of LbCu/Zn-SOD1, LbCu/Zn-SOD2 and LbFe/Mn-SOD in adults of L. bostrychophila was induced by high temperature42 ℃ stress, and the expression levels of LbCu/Zn-SOD1 and LbCu/Zn-SOD2 inadults of L. bostrychophila were significantly higher than that of the control at 1 and 2 h. The expression level of LbFe/Mn-SOD in adults of L. bostrychophila was significantly lower than that of the control at 1 h and significantly higher than that of the control at 2 h under42 ℃stress. There was no significant difference in the expression levels of LbCu/Zn-SOD1 and LbCu/Zn-SOD2 inadults of L. bostrychophila at 1 h, while that of LbFe/Mn-SOD decreased significantly at 1 h and those of LbCu/Zn-SOD1, LbCu/Zn-SOD2 and LbFe/Mn-SOD increased significantly at 2 h under 4 ℃stress as compared with that of the control. 【Conclusion】 The superoxide dismutase genes LbCu/Zn-SOD1, LbCu/Zn-SOD2 and LbFe/Mn-SOD are involved in the tolerance of L. bostrychophila to extreme temperature stress.

 Insects are the most abundant and widespread group of animals in the world that harbor complex and diverse gut microbes. Different insects differ in gut structure, gut environment, edibility, age and external environment, and the composition and abundance of gut microbes also show difference. Insect gut microbes are mainly transferred vertically and horizontally between populations and individuals, and play a vital role in nutrient metabolism, physiological behaviour, defence, detoxification and many other functions in insect hosts. Insect gut microbes can be isolated from culture media by in vitro culture methods and rapidly identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and sequencing technologies such as 16S rRNA gene sequencing. The combination of metagenomics, proteomics, metabolomics and other omics technologies makes the identification and functional prediction of gut microbes more efficient. Microbial functions can be more accurately verified by in vitro experiments, microbial supplementation, microbiota transplantation and silencing of genes associated with microbial members. Sterile insects can be obtained by high temperature treatment, lysozyme treatment, sterile feeding and antibiotic treatment for functional verification experiments. However, the most widely used antibiotic method still has limitations in application. By exploiting the characteristics of gut microbes, genetic engineering of symbiotic bacteria can be used to control pests and insect-borne infectious diseases. At present, insect gut microbes play an important role in the fields of ecology, economy, energy and environmental protection. With the development and integration of new technologies, more insect-microbe interaction mechanisms will be revealed, and pest control methods through insect gut microbes will become more diverse, environmentally friendly and efficient.

【Aim】 The effective coordination between symbiont and host insect innate immunity is an important physiological basis for maintaining their reciprocal relationship. Rickettsia is a dominant symbiont in the whitefly, Bemisia tabaci. The aim of this study is to investigate the regulation of Rickettsia on the expression of the immune genes of B. tabaci adults at different day-old ages. 【Methods】 The expression levels of immune key factor lysozyme gene BtLyz1 and defensin gene Btdef in adult B. tabaci lines with 100% infection, 45.83% infection and no infection by the symbiont Rickettsia were detected and compared, respectively, using qRT-PCR. The expression levels of BtLyz1 and Btdef, apoptosis gene BtCaspase and Rickettsia 16S rRNA gene in 100% Rickettsia-infected adults newly emerged within 24 h and adults at the 3-7-day-old and over 15-day-old were detected, respectively, using qRT-PCR. The correlations between the expression level of 16S rRNA gene of Rickettsia and the expression levels of BtLyz1 and Btdef in B. tabaci adults at different day-old ages were analyzed. 【Results】 The expression levels of BtLyz1 and Btdef in B. tabaci adults infected with the symbiont Rickettsia were significantly increased as compared to those in B. tabaci adults non-infected with Rickettsia. The highest expression level of BtCaspase was observed in B. tabaci adults at over 15-day-old infected with Rickettsia. The expression levels of Rickettsia 16S rRNA gene, BtLyz1 and Btdef  in the 3-7-day-old adults of B. tabaci were significantly higher than those in adults newly emerged within 24 h and at over 15-day-old. The expression level of Rickettsia 16S rRNA gene was significantly positively correlated with the expression levels of BtLyz1 and Btdef in B. tabaci adults newly emerged within 24 h and at the 3-7-day-old, while there was no correlation between the expression level of Rickettsia 16S rRNA gene and the expression levels of BtLyz1 and Btdef in adults at over 15-day-old. 【Conclusion】 The symbiont Rickettsia can upregulate the expression levels of immune-related genes in the host B. tabaci. However, this regulatory effect decreases significantly when the host becomes aging.

 Apis cerana cerana is a critical and important pollinator in China. This bee species has a wide distribution in various habitats, and exhibits several advantages as pollinator, e.g., agility in flight, long nectar gathering period and strong adaptability. However, in recent years, A. c. cerana has been facing an unprecedented decline in population diversity. In order to protect the genetic resources of these specific populations, researchers studied the physiology and mechanism of genetic differentiation and environmental adaptation in A. c. cerana based on geometric morphology, molecular biology and genomics technologies. Meanwhile, the diverse populations of A. c. cerana in China provided rich materials for analyzing their adaptive evolution. In this article, we summarized the research progress from the four aspects: The correlation between population genetic differentiation and environmental changes, the morphological variation and environmental adaptation, the enviroment-adaptive physiological and behavioral changes, and the genetic mechanisms behind these phenotypic changes of A. c. cerana populations. Previous studies showed that changes in physical barriers and ecological environment, especially those related to altitude and latitude, were the main reasons for the differentiation of A. c. cerana populations. Among the climatic factors, temperature, oxygen, radiation and humidity had important effects on the morphological development and eco-physiological traits of A. c. cerana. The morphological changes were mainly explained by variation in body size and color. Changes in metabolic physiology and behaviors have been evolved as a crucial adaption strategy. Population genetics and genomics based on modern genomics and molecular biology techniques showed that genes and pathways related to social division of labor, learning and perceiving behavior, information perception, growth and development, thermal adaptation and metabolism are subject to natural selection. These findings provide molecular evidence for the ability of A. c. cerana to adapt to different habitats and the evolution of bee species. However, the specific molecular evolution mechanisms for the environmental adaption of bees await further investigation. Our review on the mechanisms of genetic differentiation and environmental adaption of A. c. cerana will deepen our understanding of the evolutionary history and genetic diversity of ancient bee species, and lay a foundation for further studies on the adaptive mechanisms of social insects to different environments and the development of effective conservation strategies.

Rice, as a major staple crop in China, is directly threatened by disease and pest infestations, which jeopardize its safe production. Rice pests are diverse, and their outbreak mechanisms are complex, making the development of green control technologies challenging. Indepth research into rice pest monitoring and early warning technologies, developmental and reproductive regulation mechanisms, chemical communication mechanisms, and novel control technologies not only helps elucidate the outbreak mechanisms of rice pests but also provides new effective control targets and techniques for integrated pest management. In recent years, Chinese scholars have made significant progress in the field of rice pest research, gaining important achievements in multiple research directions, and some recent research findings were presented in this special issue. In this article, we outline the latest progresses in rice pest research at home and abroad, introduce the main research contents of this special issue, and propose the following three research directions worthy of further attention: (1) intelligent monitoring and early warning of rice pests; (2) mechanisms and evolution patterns of rice pest outbreaks; and (3) exploration of green control targets for rice pests and the construction and application of sustainable control systems.

【Aim】This study aims to preliminarily clarify the joint action mechanism of ethyl formate (EF) and methyl isothiocyanate (MITC) to Acanthoscelides obtectus through analyzing the transcriptome data of A. obtectus fumigated with EF, MITC and EF+MITC.【Methods】The A. obtectus adults were treated with fumigation of EF(22.398 μL/L), MITC(0.854 μL/L) and EF+MITC(14.764 μL/L) through wild-mouth bottle fumigation method. The control group (CK) was not fumigated. Transcriptome sequencing of the A. obtectus adults treated with fumigation of EF, MITC and EF+MITC was performed with Illumina Hi Seq^TM 4000 sequencing platform. GO classification and KEGG enrichment analysis were performed on differentially expressed genes (DEGs). Six DEGs were selected for RT-qPCR validation.【Results】 There were 171 and 293 DEGs in the CK vs EF and CK vs MITC comparative groups, respectively, and most of them were up-regulated. However, the number of DEGs in the CK vs EF+MITC comparative group was 1 745, and most of them were down-regulated. GO classification of DEGs showed that DEGs in the  CK vs EF and CK vs MITC comparative groups were mainly enriched in cellular anatomical entity, binding, and catalytic activity, while those in the CK vs EF+MITC comparative group were mainly enriched in cellular anatomical entity, binding, and cellular process. KEGG pathway enrichment analysis of DEGs showed that DEGs in the CK vs EF comparative group were mainly enriched in pathways of protein digestion and absorption, lysosome and protein processing in endoplasmic reticulum, those in the CK vs MITC comparative group were mainly enriched in pathways of focal adhesion, ECM-receptor interaction and insect hormone biosynthesis, and those in the CK vs EF+MITC comparative group were mainly enriched in RNA transport, DNA replication and mismatch repair. In addition, the expression levels of two and three detoxification enzyme genes in A. obtectus adults in response to EF and MITC fumigation treatments were significantly down-regulated, respectively, however, the expression levels of five detoxification enzyme genes in A. obtectus adults in response to EF+MITC fumigation treatment were significantly down-regulated as compared with those in the CK. The expression trends of the six selected DEGs were basically consistent with the transcriptome data.【Conclusion】The results of this study indicate that the combination of EF and MITC has a synergistic effect, which can induce cell genotoxic damage in A. obtectus. The inhibition of expression of detoxification enzyme genes seems to be the main reason for its synergistic effects. In this study, the molecular mechanism of fumigation and insecticidal effect of the mixture of EF and MITC on A. obtectus was preliminarily clarified, which provides an important basis for the further study on the combined action mechanism of EF and MITC on A. obtectus.

 Honeybee queens share the same genetic background with the workers, and they both are developed from fertilized eggs. Nutritional and spatial variances during the development lead to significant morphological, physiological and behavioral dimorphism between the two castes. The insulin signaling pathway (IIS) regulates the behavior of worker bees, thus influencing their longevity. Longer longevity of queen bees is associated with increased oxidative stress and enhanced stress defense. Vitellogenin (Vg) interacts with juvenile hormone (JH), and the relatively high level of Vg and low level of JH usually lead to longer longevity. Telomerase activity and telomere length are influenced by the development and caste of honeybees. Queens inherit longer telomere length and maintain higher telomerase activity than workers. Overwintering worker bees live longer and show higher telomerase activity than the summer worker bees. Mitochondrial damage is a sign of senescence, while the mitochondrial function of the aged queen remains vigorous. Senescence is closely related to DNA methylation, and DNA methylation and histone modification play important roles in the regulation of plasticity in social insects. With the increase in population aging and the high prevalence of senescence-related diseases, “healthy aging” has triggered a series of concerns in life sciences and social sciences. Studies on honeybee senescence and longevity regulation will provide an important reference for the biology of senescence.

Lures can stimulate the behavioral responses of fruit flies to a certain extent and play an important role in the green prevention and control of fruit flies. As one of the most important lures, and coming from some plant volatiles or parapheromones, male lures of fruit flies have a significant attractive effect on male fruit flies. Male fruit flies will not only be attracted by the smell of male lures but also feed on the lures, which will be metabolized into different substances in male adults, and then play the corresponding function. In this review, combined with the studies on the feeding effects, we reviewed the research progress of six male lures of fruit flies, namely methyl eugenol, raspberry ketone, zingerone, cuelure, 3-hydroxy-α-ionone and β-caryophyllene, and their metabolism, mainly including the feeding behavior and metabolic changes of male fruit flies, the influence of feeding effect on the behavioral responses of fruit flies, the attractive effect of male fruit flies fed on lures on female and male fruit flies, and the change of mating success rate. In the exploration of the feeding effect, rectal gland is the focus of pheromone isolation and storage, and the waxy, water-resistant film composed of hydrocarbons covering insect body surface is also a potential focus of research. At the same time, exploring the role of antennae and maxillary palp in the lure perception process of fruit flies will help to reveal the complex mechanism behind feeding phenomenon more comprehensively and profoundly. It is expected to provide new ideas and guidelines for the development of fruit fly lures and add more diversified means and approaches for the green ecological prevention and control of fruit flies.