【Aim】 The objective of this study is to analyze the number and distribution of microsatellites in the whole genome of the German cockroach, Blattella germanica, and get the functional annotation information of genes containing microsatellites in exons. 【Methods】 The microsatellite number, repetition and location information were calculated by using microsatellite search tool. The distribution information of microsatellites in the genome was calculated by custom Python scripts, and all genes containing microsatellites were annotated by using the programs of Blast2Go and KAAS. 【Results】 A total of 604 386 simple sequence repeats (SSRs) with 1-6 bp nucleotide motifs were identified, with a total length of 15 301 255 bp, indicating that about 0.75% of the B. germancia genome (2.04 Gb) is occupied by SSRs and that there is a locus per 3.37 kb. The length of the microsatellite sequences mainly ranges from 12 to 60 bp. Among different types of microsatellites, trinucleotide microsatellites (226 876, 37.54%) are the most abundant SSRs, followed by tetranucleotide microsatellites (150 355, 24.88%), mononucleotide microsatellites (141 167, 23.36%), dinucleotide microsatellites (60 877, 10.07%), pentanucleotide microsatellites (21 570, 3.57%) and hexa-nucleotide microsatellites (3 541, 0.59%). The predominant repeat types are ATT, AAT, A, T, AAAT, ATTT and AT, with a total number of 411 789, accounting for 68.13% of the total SSRs. The number of each of these 7 categories is greater than 30 000. There are 2 372 microsatellites in the exons of 1 481 genes. The results of GO annotation indicated that 434 GO terms are classified as cellular component, 402 GO terms are related to molecular function and 660 GO terms are related to the biological process. Aligned to KEGG database, most of these genes are associated with metabolism, followed by genes related to organismal system, and genes related to genetic information processing are the least. 【Conclusion】 This study lays a foundation for further in-depth analysis of microsatellite function and developing microsatellite markers of B. germanica.

【Aim】 Trehalose-6-phosphate synthase (TPS) is one of the main enzymes in regulating trehalose levels in the insect haemolymph. This study aims to clone and characterize the TPS genes in Blattella germanica and to profile their expression patterns in extreme temperature environments. 【Methods】 The full-length cDNA sequences of two TPS genes were cloned using RACE technology, and their relative expression levels in different tissues of the 5th instar larvae and under cold (exposed to 10℃ and 0℃ for 1 h, respectively) and heat stress (exposed to 40℃ and 46℃ for 30 min, respectively) were measured using the real-time quantitative PCR (qRT-PCR) technique. 【Results】 The full-length cDNAs oftwo TPS genes were cloned from B. germanica, and named BgTPS1 and BgTPS2, respectively. BgTPS1 (GenBank accession no.: KR050213) is 2 987 bp in length and has an open reading frame (ORF) of 2 502 bp, encoding a protein of 833 amino acids. BgTPS2 (GenBank accession no.: KR050214) is 3 212 bp in length and has an ORF of 2 469 bp, encoding a protein of 822 amino acids. The qRT-PCR analysis revealed that BgTPS1 and BgTPS2 mRNA were mainly expressed in the fat body of the 5th instar larvae, with the level of BgTPS2 mRNA 3.9-fold as high as that of BgTPS1. Under the extreme temperature induction, the expression levels of BgTPS1 and BgTPS2 increased, and the level of BgTPS2 mRNA was much higher than that of BgTPS1 under all stress conditions. The expression levels of both TPS genes were much higher under cold induction (0℃) than under other temperature induction. 【Conclusion】 The two TPS genes were highly expressed in the fat body of the 5th instar larvae of B. germanica, and the level of BgTPS2 mRNA was much higher than that of BgTPS1. The expression levels of BgTPS1 and BgTPS2 increased under both cold and heat stresses. The results provide a foundation for the further research of TPS genes and their roles in the regulation of temperature acclimation in insects.

【Aim】 The objective of this study is to analyze the distribution of AhetPBP2 in the antenna of Atrijuglans hetaohei. 【Methods】 The cDNA was synthesized with the total RNA extracted from antennae of newly emerged adults of A. hetaohei. The cDNA segment of AhetPBP2 was amplified by RT-PCR with degenerate primers. The full-length cDNA sequence of AhetPBP2 was obtained by RACE. AhetPBP2 without the signal peptide sequence was expressed in Escherichia coli BL21(DE3). Recombinant AhetPBP2 was purified through Ni-chelating affinity chromatography. The polyclonal antiserum was prepared by immunizing a male New Zealand white rabbit with the purified AhetPBP2. Immunohistochemical analysis was performed with the polyclonal antibody of AhetPBP2. 【Results】 The full-length cDNA sequence of AhetPBP2 is 923 bp. Its open reading frame is 504 bp, encoding a protein of 167 amino acids with the molecular weight of 19.26 kD and the isoelectric point of 5.47. After induction with 1 mmol/L IPTG for 10 h, the soluble recombinant protein AhetPBP2 was obtained. Western blot showed that the recombinant protein was expressed successfully. ELISA detection showed that the titer for the polyclonal antibody was 1:1 024 000. Immunohistochemical analysis showed that parts of the antennal sensilla were labeled by AhetPBP2 polyclonal antibody. 【Conclusion】 AhetPBP2 is localized on parts of antennal sensilla of A. hetaohei adults, suggesting that these antennal sensilla may be involved in the perception of sex pheromones.

【Aim】 Ecdysteroid receptor (EcR) was a superfamily nuclear receptor, and it can form a heterodimeric complex EcR/USP with ultraspiracle (USP) protein to adjust the biological activity of 20-hydroxy molting ketone (20E) and regulate the developmental, abnormal and reproductive processes in insect lifecycle. This study aims to clone the full-length cDNA of EcR gene from Ectropis obliqua Prout, and to understand the characteristics of its encoding protein and its expression patterns. 【Methods】 The complete cDNA was cloned from E. obliqua by RT-PCR and RACE technologies. The bioinformatics analysis was carried out by bioinformatics software and editing on online website. The mRNA levels of EcR in different developmental stages and different tissues of the 6th instar larvae were investigated by real-time quantitative PCR (qRT-PCR). 【Results】 The EcR cDNA was cloned successfully from E. obliqua and named Eo-EcR (GenBank accession no. KP869130.1). Its complete length cDNA is 2 268 bp, including a 1 728 bp open reading frame (ORF), which encodes 576 amino acids. Phylogenetic treeanalysis and alignment of amino acid sequences showed that Eo-EcR is highly conserved among insects, especially in Lepidoptera. The results from tertiary structure and function domain prediction indicated that Eo-EcR has three classic structure models and the alpha helix is the dominant structure. It also contains a single functional site with a uni-C₄ type zinc finger structure. qRT-PCR results showed that the expression level of Eo-EcR was higher in the 5th and 6th instar larval stage and adult stage compared to other stages. Tissue expression profiling showed that the expression level of Eo-EcR was the highest in prothoracic gland while lowest in hemolymph. 【Conclusion】 The sequence of nucleotide and characteristics of the encoded amino acid sequence of Eo-EcR were clarified. These results provide a foundation for further researches on the molecular function of Eo-EcR, and bring a new insight for the design of target insecticide to better control E. obliqua.

【Aim】 The aim of this study is to clone the full-length cDNA of mab-21 gene in the head of the Chinese honeybee, Apis cerana cerana, and then to analyze its expression characteristics in different developmental stages of the workers and after infection of mites, in attempt to provide a theoretical support for revealing the resistance mechanism of A. cerana cerana to Varroa mites. 【Methods】 The cDNA sequence of mab-21 in A. cerana cerana was cloned by RT-PCR, and a quantitative analysis of its expression level in the head of workers at different developmental stages (newly emerged bee, nurse, guarder and forager) and after infection of Varroa destructor mites was conducted using real-time PCR. 【Results】 The cDNA sequence of mab-21 was cloned from A. cerana cerana, and named as Accmab21 GenBank accession no. KR000001). Its open reading frame (ORF) is 1 098 bp in length, encoding 395 amino acids with the predicted molecular weight of 41.63 kD and the theoretical isoelectric point of 8.53. Phylogenetic analysis indicated that mab-21 of A. cerana cerana, A. mellifera, A. florea and Bombus impatiens gather in the same clade. The mab-21 transcript was clearly detected in different developmental stages of the workers of A. cerana cerana, and was significantly higher in nurses than in other stages (P<0.05). After being inoculated with V. destructor, the expression of mab-21 in the nursesand guarders significantly decreased as compared to the control (P<0.05), but the expression level of mab-21 showed no obvious regularity in newly emerged bees and foragers. 【Conclusion】 These results suggest that mab-21 may be involved in the resistance to mites in A. cerana cerana.

【Aim】 The objective of this study is to identify the composition of female sex pheromones of the box tree moth, Diaphania perspectalis in China and to understand the the differential attractiveness of these components to D. perspectalis moths. 【Methods】 The sex pheromone extract of female calling moths of the normal form D. perspectalis was identified and analyzed with gas chromatography-mass spectrometry (GC-MS) , and confirmed by the synthetic compound samples. The olfactory responses of D. perspectalis to sex pheromones and their isomers were investigated with electroantennogram (EAG). The field trapping tests were carried out to pinpoint the optimized blends. 【Results】 (Z)-11-hexadecenal (Z-11-16:Ald) was the major component found in the sex pheromone extract of female calling moths of D. perspectalis, (E)-11-hexadecenal (E-11-16:Ald) was the very minor component, while (Z)-11-hexadecenol(Z-11-16:OH) was not detected in all extracts. The EAG recording results revealed that the antennae of male moths of D. perspectalis had strong responses to Z-11-16:Ald, E-11-16:Ald, (Z)-9-hexadecenal (Z-9-16:Ald) and Z-11-16:OH, but had very weak responses to (Z)-11-hexadecenyl acetate (Z-11-16:Ac) and (E)-11-hexadecenyl acetate (E-11-16:Ac) compared with to the general green leave volatile Z-3-hexenyl acetate. The EAG responses of the male moths of D. perspectalis to Z-11-16:Ald, E-11-16:Ald and Z-9-16:Ald increased dramatically with the concentration. The number of the normal form male moths of D. perspectalis attracted by single component Z-11-16:Ald showed no statistically significant difference from that by the mixture of Z11-16: Ald and E-11-16:Ald in the field tests. However, the single component Z-11-16:Ald showed no attractiveness to the melanic form male moths of D. perspectalis , but showed attractiveness when E-11-16:Ald was added. The highest number of melanic form male moths of D. perspectalis was attracted by the mixture Z-11-16:Ald:E-11-16:Ald at the ratio of 250 μg:250 μg, and the mixture Z-11-16:Ald:E-11-16:Ald at the ratio of 400 μg:100 μg and 429 μg:71 μg were also attractive to the normal form male moths of D. perspectalis. Z-11-16:Ald was strongly attractive to male moths of Mythimna separata, but this attractivity was suppressed by E-11-16:Ald.【Conclusion】Z-11-16:Ald is the major component of pheromone for the normal form of D. perspectalis moths in China. E-11-16:Ald might play a minor synergistic role and the species specificity in D. perspectalis sex pheromone blend. There is some difference in the olfactory responses of sex pheromone between the normal form and the melanic form male moths of D. perspectalis. The sex pheromone of the melanic form of D. perspectalis has a component close to that in Japan, which is the mixture of Z-11-16:Ald:E-11-16:Ald with the ratio of 1:1, and E-11-16:Ald is required for the attractiveness of the pheromone mixture.

【Aim】 The quality and type of a prey play key roles in selection, consumption and trophic transfer efficiencies by its predators. The nutritional quality of a plant can affect that of the herbivore, which in turn can affect the herbivore’s nutritional quality as the prey for predators. In order to further understand the tritrophic interaction among host plants, preys and predators, the effects of the prey’s host plant species on the predator were investigated. 【Methods】 The effects of the prey’s host plant species on the predator were assessed by studying the consumption and utilization of the cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), reared on five species of Cucurbitaceae by the 4th instar larvae and female adults of Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae). 【Results】 The food consumption was the highest for the 4th instar larvae and the female adults of H. variegata when they were fed on the cotton aphids reared on Cucurbita moschata var. melonaeformis. The food consumption was the lowest for the 4th instar larvae and female adults of H. variegata when they were fed on the cotton aphids reared on Lagenaria siceraria var. gourda. The relative growth rate (RGR), efficiency of conversion of ingested food (ECI) and efficiency of conversion of digested food (ECD) were the highest for the 4th instar larvae of H. variegata when they were fed on the cotton aphids from Cucumis melo var. cantalupensis. The RGR did not differ significantly in female adults of H. variegata when they were fed on the cotton aphids reared on C. sativus and C. pepo var. medullosa, while the ECI and ECD did not differ significantly when they were fed on the cotton aphids reared on C. sativus, L. siceratia var. gourda and C. pepo var. medullosa. Therefore, the cotton aphids reared on C. melo var. cantalupensis are more suitable preys for the 4th instar larvae of H. variegata, whereas those reared on C. sativus, L. siceratia var. gourda and C.pepo var. medullosa are more suitable preys for the female adults. 【Conclusion】 The predation efficiency of H. variegata on the cotton aphids is related to the host plant species. This result makes a theoretical foundation for further using the feeding habits of an insect to control insect pests.

【Aim】 Rearing host and wasp age affect the egg load of Trichogramma wasps. In this study, in order to understand the relationship between rearing host and egg load or between the female size and egg load of Trichogramma wasps, we studied the effects of rearing hosts on the female size and egg load of wasps of three Trichogramma species (Trichogramma dendrolimi, Trichogramma ostriniae and Trichogramma japonicum) using Corcyra cephalonica eggs and Ostrinia furnacalis eggs as hosts.【Methods】 The three Trichogramma species were reared in climatic cabinet (25±1℃, photoperiod 14L:10D). Female egg load was observed at different ages (0-72 h-old) by dissecting the wasps under microscopy. Female hind tibia length was measured, and the relationship between female egg load and female age as well as between body size and rearing hosts was analyzed. 【Results】 The egg load of wasps of three Trichogramma species increased as female age increased within 48 h after wasp emergence. The egg load of 72 h-old wasps was lower than that of 48 h-old wasps of the corresponding species except for T. ostriniae wasps emerged from C. cephalonica eggs and T. dendrolomi  wasps emerged from O. furnacalis eggs. The egg load of T. ostriniae wasps emerged from O. furnacalis eggs was significantly higher than that of the wasps emerged from C. cephalonica eggs, whereas the result was opposite for T. dendrolimi (except 12 and 24 h-old) and T. japonicum. The egg load of T. dendrolimi wasps was the highest and T. japonicum held the least eggs among three Trichogramma species of the same age when C. cephalonica eggs were used as the rearing host. When the wasps emerged from O. furnacalis eggs, egg load of T. ostriniae was the highest and T. japonicum held the least eggs among the three Trichogramma species. There was a significant positive liner relationship between egg load and female size for the three Trichogramma species, and the relevance degree increased with female age. 【Conclusion】 Hind tibia length can be used as an index to evaluate the quality of T. dendrolimi,T. ostriniae and T. japonicumwasps. Rearing host, Trichogramma species and female adult age significantly affect the egg load of Trichogramma wasps. Host suitability also affects the size of Trichogramma wasps, and suitable rearing host helps to improve the quality of Trichogramma wasps.

【Aim】 The litchi fruit borer, Conopomorpha sinensis Bradley, is the most serious pest of litchi and logan in China. The objective of this study is to determine the number of larval instars of C. sinensis and the developmental duration of each stage at different temperatures. 【Methods】 The head capsule width of C. sinensis larvae was measured to determine the number of larval instars. The developmental duration of each stage at 17-38℃ was determined in the laboratory via artificial rearing, and the correlation between developmental rate and temperature was analyzed through the linear regression model. 【Results】The results in the frequency histogram of the head capsule width showed that the frequency istribution could be obviously divided into 5 areas, suggesting that C. sinensis has five larval instars, which follows the Dyar’s law. The average head capsule width of the 1st-5th instar larvae was 0.105, 0.170, 0.265, 0.435 and 0.652 mm, respectively. Temperature had significant effects on the developmental duration of egg, larva and pupa, and their durations all reduced with increasing temperatures, while the correlation between the developmental rate and temperature fitted with the linear regression model. C. sinensis could complete a whole generation from 20 to 32℃, but the larvae only developed to the 3rd instar at 17℃, few pupae could complete eclosion at 35℃ and few eggs could hatch at 38℃. The duration of one life cycle, pupa and preoviposition was 41.16-19.34, 12.74-5.35 and 4.75-4.22 d, respectively. However, temperature had no effect on the preoviposition period. Appropriate living temperature for C. sinensis larvae was from 20 to 35℃. The duration of the 1st, 2nd, 3rd, 4th and 5th instar larva and prepupa at 20-32℃ was 4.50-1.17, 2.09-1.40, 2.84-1.00, 3.41-1.18, 3.00-1.37 and 2.41-0.69 d, respectively. The egg could normally hatch at temperatures from 17-35℃, and its duration was 7.73-2.09 d. 【Conclusion】 C. sinensis has five larval instars instead of four instars reported in the previous research. Within the temperature range of 20-32℃, the durations of egg, each instar larva and pupa reduce with increasing temperatures. These results will provide data support for the forecast of C. sinensis.

The voltage-gated sodium channels of insects exist on the membrane of all excitable cells. Because of their essential role in the generation and transmission of potential action and electrical signaling in excitable cells, sodium channels are the target site of the organochlorine and pyrethroid insecticides. Due to massive use of organochlorines and pyrethroids for the control of agricultural and medical insect pests, the number of insect pests that have developed resistance to these insecticides is drastically increasing. One major mechanism of the resistance is known as knock-down resistance (kdr). Insects exhibiting kdr have reduced target-site (sodium channel) sensitivity to organochlorines and pyrethroids, mainly resulting from one or more nonsynonymous point mutations in the insect sodium channel protein. In this article, we reviewed the transmembrane topology structure, function, evolution and gene cloning of voltage-gated sodium channels. More importantly, we summarized the known 40 nonsynonymous mutations from more than 40 insect species, the mRNA alternative splicing and editing of the sodium channel genes, and their association with insecticide resistance. We also reviewed the insecticide resistance mechanisms due to protein structure changes resulting from these mutations. These researches provide a comprehensive information frame for further identification of mutations and molecular mechanisms associated with organochlorine and pyrethroid resistance, and the development of molecular monitoring methods of the resistance.

Plant secondary metabolites can deteriorate the feeding behavior, growth and reproduction of insects, and even exhibit toxicity to insects. During fighting against the influences and toxicity of plant secondary metabolites from host plants, insects gain adaptability to plant secondary metabolites by multiple measures such as avoiding feeding or detoxifying and metabolizing plant secondary metabolites. The insect metabolic enzymes including P450s and glutathione-S-transferase play key roles in the detoxification metabolism of plant secondary metabolites and the adaptability of insects to host plants. The metabolic enzymes of insects are involved in not only the metabolism of plant secondary metabolites, but also the metabolism of insecticides. Therefore, the adaptability of insects to host plants is closely related to the insecticide tolerance and resistance of insects. The activities of P450s and GSTs and the expression of these detoxification enzyme genes in insects could be affected by the exposure of plant secondary metabolites, and these not only result in the adaption of insects to the defense of host plants, but also affect the ability of detoxification metabolism to insecticides and the insecticide tolerance and resistance of insects. Understanding the metabolic adaptation mechanisms of insects to plant secondary metabolites and its roles in affecting the insecticide resistance of insects are of great importance to uncover the insecticide esistance mechanisms of insects. The influences of plant secondary metabolites on insects, the metabolic mechanism of insects to host plant secondary metabolites, and the effects of insect adaptability to plant secondary metabolites on insecticide tolerance and resistance of insects were reviewed in this article.

【Aim】 This study aims to explore the characteristics of the symbiotic bacterium Tremblaya princeps in Phenacoccus solenopsis through observing its morphology, location and dynamics in different stages of hosts. 【Methods】 The ultrastructure of T. princeps was observed by transmission electron microscopy, and its location and quantitative changes were determined using real-time PCR. 【Results】 T. princeps is located in different tissues compared between females and males of the host P. solenopsis. In females, T. princeps is located only in bacteriome, but not in any other tissues or organs of the host. Size of bacteriome had a significant linear relationship with host body size, and its expanding rate accelerated as the host adults developed. In males of the host, the density of T. princeps increased dramatically before the pupal stage, and then decreased as the adult emerged. Bacteriome collapsed when the males of the host entered the pre-pupal stage. 【Conclusion】 Our results suggest that the infection status of T. princeps is varied with host sexuality and correlated to host individual development.

【Aim】 The study aims to get the sensitive spectral range of Anomala corpulenta Motschulsky to light.【Methods】 The phototaxis behavior of A. corpulentain response to spectral sensitivity was tested under 14 monochromatic lights ranging from 340 nm to 610 nm in the laboratory. 【Results】 A. corpulenta adults showed phototaxis reaction to all the tested monochromatic wavelengths between 340 nm and 610 nm spectrum, and the phototactic behavior response rates were higher in the monochromatic light UV (405 nm), blue light (460 nm) and green light (505 and 570 nm) in male and female adults. Sexes affected their phototactic behaviour, but only affected the levels of response rate peaks. The spectral photophobic behavior response of A. corpulenta adults showed no significant difference between the two sexes, and the photophobic behavior response rates were higher in the spectrum of ultraviolet region (380 nm), blue light (440 nm) and green light (492 and 505 nm). 【Conclusions】 There are differences in phototaxis of A. corpulenta to light between different wavelengths, and gender is an important factor affecting the spectrum of behavioral responses. The results not only provide a necessary theoretical foundation for further research of light vision in A. corpulenta, but also provide a scientific basis for the use of phototaxis to the integrated management of scarab beetles.