【Aim】 The Drosophila Dichaete gene is a gene of Sox B subfamily, which is expressed throughout embryogenesis and plays an important role in early development. Dichaete also exists in the leg disc of larvae, but little is known about its function in legs. The aim of this study is to investigate the effect of ectopic expression of Dichaete on leg development of Drosophila and to explore the underlying mechanism. 【Methods】en-Gal4 and UAS-Dichaete of Drosophila melanogaster were crossed, and Dichaete was ectopicly expressed under the control of en-Gal4 in the progeny. Legs of the progeny were cut off and their structure was observed using binocular microscope. Immunohistochemistry was used to detect cell apoptosis and Distal-less (Dll) expression in leg discs. 【Results】 The ectopic expression of Dichaete resulted in distal leg defects of adults, enhanced apoptosis in the 3rd instar larvae, and increased expression of distal-less in D. melanogaster, but had no effect on Wg and Dpp signaling activities. Inhibition of apoptosis could not rescue the leg defects. 【Conclusion】 Ectopic expression of Dichaete interferes with maintenance of distal-less gene, leading to structural defects of adult legof D. melanogaster.

【Aim】 This study aims to understand the transcriptome features of Myzus persicae of different wing types (winged and apterous), to enrich its transcriptome data, and to reveal the molecular mechanisms of wing dimorphism of this insect. 【Methods】 The differences in transcriptome expression between nymphs, apterous adults, and winged adults of M. persicae were detected by high-throughput sequencing technology Illumina HiSeq^TM2000. The expression patterns of wing type related genes were analyzed by real-time quantitative PCR (qPCR). 【Results】 The percentage of nucleotides with the quality score over 20 was not less than 94% (GenBank accession numbers: SRR6112438, SRR6112436 and SRR6112437). All reads were assembled into 128 065 unigenes with an average length of 607.08 bp. The resulting sequences were annotated to databases NR, NT, KOG, GO, KEGG, etc., and a total of 128 065 unigenes were annotated. Gene expression analysis showed that the genes of flight proteins, peptide hormones, receptor proteins, etc., which are related to wing formation during growth, were differentially expressed between winged adults and apterous adults or nymphs. qPCR analysis showed that there were significant differences in the expression levels of wing type differentiation related genes including Bursicon (bur- α and bur-β), flightin (Fln), Wntless (Wnt), Distal-less (Dll), Decapentaplegic (Dpp), juvenile hormone epoxide hydrolase gene (JHEH) and ecdysone receptor gene (EcR) between winged adults and apterous adults. 【Conclusion】 The expression levels of bur-α, bur-β , Fln, Wnt, Dll, Dpp, JHEH and EcR change during wing formation in M. persicae. Our results show the general expression characteristics of wing formation genes and provide a basis for further research of wing formation in M. persicae.

【Aim】 This study aims to establish the antennal transcriptome database of the azuki bean weevil, Callosobruchus chinensis, and to obtain the genetic data. 【Methods】The antennal transcriptome of C. chinensis adults was sequenced using an Illumina HiSeq 4000 platform and subjected to bioinformatics analysis. 【Results】 A total of 51.10 Gb clean data (NCBI SRA accession no.: SRP119884) were obtained, and the clean reads were assembled into 83 535 unigenes with an N50 length of 1 492 bp and 15 075 unigenes over 1 kb in length. A total of 22 148 unigenes in the antennal transcriptome of C. chinensis adults were annotated using BLASTX search against the public databases. Most unigenes (18 744 unigenes) were annotated to NR database, and the unigenes of C. chinensis had the highest similarity (39.57%) with those of Tribolium castaneum. All unigenes were divided into 54 branches of three categories (cellular components, molecular function and biological processes) using Gene Ontology (GO), and a lot of unigenes were annotated to be related to metabolic processes, binding activities and cellular processes. In KEGG database, 9 084 unigenes were assigned to 289 known metabolic pathways. Among these, most unigenes (516) are involved in metabolic pathways of ribosome. By further screening and identification, 140 olfaction-related genes of C. chinensis including 12 odorant binding protein (OBP) genes, 4 chemosensory protein (CSP) genes, 116 odorant receptor (OR) genes, 1 ionotropic receptor (IR) gene and 7 sensory neuron membrane protein (SNMP) genes were identified, and their expression levels were evaluated based on FPKM value. 【Conclusion】 This study obtained the antennal transcriptome data of C. chinensis. The results provide a foundation for the further study of gene functions and molecular mechanisms of olfactory reception of C. chinensis.

【Aim】 Catalase (CAT) plays an important role in decomposing hydrogen peroxide into water and oxygen which makes an organism avoiding the damage of oxidative stress. This study aims to explore the roles of CAT in anti-oxidative stress in the oriental armyworm, Mythimna separata. 【Methods】 The complete cDNA and genomic sequence of CAT in M.separata were cloned by RT-PCR and RACE. Bioinformatics programs were used to analyze the sequence characteristics of the gene and encoded protein. The expression levels of CAT in M. separata in different developmental stages （egg, 1st-6th instar larva, pupa and adult), tissues of the 5th instar larva (head, cuticle, foregut, midgut, hindgut and Malpighian tubules), and larvae under chlorpyrifos exposure, high temperature stress and larval crowding conditions were detected by quantitative real-time PCR (qPCR). 【Results】 The complete cDNA of CAT obtained from M. separata was named as MsCAT (GenBank accession no.: MF737386), which is 1 846 bp in length, with a 1 602 bp opening reading frame (ORF) encoding 533 amino acids. Sequence analysis indicated that MsCAT has three typical motifs of CAT family, including one proximal active site (⁸⁸FDRERIPERVVHAKGAGA¹⁰⁵), one NADPH binding site (²¹⁶VTHQVLYLFGD²²⁶）and one proximal heme-ligand signature sequence (³⁷⁹RLFSYSDTH³⁸⁶). The DNA sequence of MsCAT contains a 612 bp intron that inserts into the location behind the 99th bp of the encoding region. Phylogenetic analysis indicated that CATs from Noctuidae moths could be assigned to one well-supported cluster. MsCAT was expressed in various developmental stages and tissues of the 5th instar larva of M. separata, and exhibited the highest expression level in the 6th instar larval stage and larval midgut, respectively. MsCAT was significantly up-regulated in larvae fed on corn leaves treated by low concentration (1 μg/mL) of chlorpyrifos for 24 h, but down-regulated in larvae fed on high concentrations of chlorpyrifos. The expression level of MsCAT was significantly up-regulated in larvae exposed to temperatures from 33 to 37℃, but declined in larvae exposed to 39℃ as compared with that of the control (24℃). The expression level of MsCAT in M. separata larvae was negatively related to their crowding degree. 【Conclusion】 The obtained full-length cDNA of MsCAT encoding CAT in M. separata is reliable, and MsCAT may play an important role in development and oxidative stress tolerance of M. separata.

【Aim】 Cuticular proteins (CPs) are abundant in insects, playing important roles in insect growth and development. This study aims to enrich different types of CPs in Antheraea pernyi and to determine the expression patterns of CPs during different developmental stages. 【Methods】 Two CP genes were cloned from cuticle of A. pernyi larvae using PCR and 3′ RACE technology, and the phylogenetic relationship was analyzed by bioinformatics methods. The expression patterns of the two genes in different tissues of larvae and during embryonic development of A. pernyi were analyzed by semi-quantitative RT-PCR, and the relative expression levels of the two genes in A. pernyi at different developmental stages and in the 3rd instar larvae after RNAi treatment were measured using real-time quantitative PCR (qPCR) technology. 【Results】 Two CP genes were cloned from A. pernyi and named ApCP12 (GenBank accession number: MF318874) and ApCP23 (GenBank accession number: MF318875), respectively. Bioinformatic analysis indicated that ApCP12 is 690 bp in length with an open reading frame (ORF) of 336 bp, encoding a protein of 111 amino acid residues with the calculated molecular weight of 12 kD, while ApCP23 is 1 243 bp in length with an ORF of 594 bp, encoding a protein of 197 amino acid residues with the calculated molecular weight of 23 kD. Both proteins contain RR-1 consensus and are classified in different clusters with RR-2 cuticular proteins by phylogenetic analysis. Tissue-specific mRNA expression profiling showed  that ApCP12 was more widely distributed than ApCP23. In the progress of embryonic development, the expression level of ApCP12 increased gradually. During larval ecdysis stage, the expression level of ApCP12 increased by 3-fold, and that of ApCP23 increased by 13-fold in 3 d after ecdysis than in molting stage. During pupal melanization, the expression level of ApCP12 was higher than that of ApCP23. The expression levels of the two genes had no significant changes during the earlier stage of pupal eclosion, while on the last day before eclosion, the expression levels of ApCP12 and ApCP23 increased by 3.5- and 3-fold, respectively, as compared with that on the first day of 20E injection. After RNAi treatment, the expression levels of ApCP12 and ApCP23 in the 3rd instar larvae were downregulated 5- and 3-fold, respectively. 【Conclusion】 The results suggest that these two CPs of subtribe RR-1 participate in the cuticle building of larva, pupa and adult and have a close relationship with the whole life cycle of A. pernyi development.

【Aim】 To reveal the bacterial community structure and diversity in the small brown planthopper (SBPH), Laodelphax striatellus. 【Methods】 The Illumina MiSeq high-throughput sequencing platform was used to sequence the V3-V4 regions of the bacterial 16S rRNA gene in the newly emerged female and male adults (24 h after emergence) of L. striatellus. The numbers of sequences and operational taxonomic units (OTUs) and the abundance and diversity of the bacterial communities were analyzed using the related softwares and databases including USEARCH and Silva. 【Results】 A total of 29 333 valid tags and 55 OTUs were obtained from female adults of L. striatellus, while the numbers of valid tags and OTUs from male adults were 25 919 and 57, respectively. Among them, 20 OTUs were shared between the two samples of female and male adults, and the unique OTU numbers for female and male adults were 35 and 37, respectively. The total OTUs of the two samples were annotated into 7 phyla, 15 classes, 23 orders, 33 families, 56 genera, and 73 species. At the levels of phylum, class, order and family, the most dominant bacteria in both samples of female and male adults were from Proteobacteria (99.96% for female and 99.16% for male), Alphaproteobacteria (97.76% for female and 97.84% for male), Rhodospirillales (83.92% for female and 53.21% for male), and Acetobacteraceae (83.90% for female and 53.17% for male), respectively. At the genus level, the dominant bacteria with the highest abundance belonged to an undetermined genus in Acetobacteraceae (unclassified Acetobacteraceae). The second dominant genus was Wolbachia, accounting for 13.81% and 44.52% in female and male adults, respectively. At the species level, the numbers of specific bacterial species in male and female adults were 21 and 32, respectively. However, the abundance of the sex-specific species in the two samples was generally low (less than 0.5%). 【Conclusion】 The results indicate that the bacteria in L. striatellus adults are diverse and the bacterial community structure and diversity are different between female and male adults. This study lays the foundation for further studies on the excavation and utilization of microorganism resources for the biocontrol of L. striatellus.  

【Aim】 Determining the susceptibility of field populations of the whitefly, Bemisia tabaci in Hainan, China to two novel insecticides, cyantraniliprole and flupyradifurone, can help to provide the reference for the rational application of the insecticides and resistance monitoring of its field populations. 【Methods】 The cryptic species identity of field populations of B. tabaci collected from six localities in Hainan Province, southern China in January, 2017 was identified by sequencing of mitochondrial cytochrome oxidase I gene (mtCOI) and PCR-RFLP analysis of mtCOI. The LC₅₀ values of cyantraniliprole and flupyradifurone against these populations were measured using leaf-dip method. 【Results】 Among the six populations, the population from Jiyang, Sanya city was identified as the cryptic species MEAM1, those from Yongfa, Chengmai county and Chongpo, Ledong county were identified as the mixed populations of the cryptic species MEAM1 (<10%) and MED (94.6% and 92.9%, respectively), and the other three were identified as the cryptic species MED. By comparison with the LC₅₀ value of cyantraniliprole against the susceptible population, the population from Shisuo, Ledong county, had developed low-level resistance to cytraniliprole (RR: 5-10), while the other five were susceptible (RR<5). And by comparison with the LC₅₀ values of flupyradifurone, all the six field populations were susceptible (RR<3). 【Conclusion】 Cyantraniliprole and flupyradifurone can be used as candidate insecticides in the control and resistance management of B. tabaci, and more attention should be paid to the resistance development of B. tabaci to cyantraniliprole in the field.

【Aim】 This study aims to determine the effects of three low doses of fluvalinate on the quality of reared queens of the western honey bee, Apis mellifera. 【Methods】 Queens were caged to lay eggs for 8 h. The larvae hatched from those eggs were transplanted into queen cells for queen rearing, and fed with 2 μL syrup containing different concentrations of fluvalinate (0, 0.05, 0.5 and 5 mg/kg) since the 2nd day of larval stage using a micro sampling syringe injector. The numbers of capped queen cells after feeding for three days and emerged queens in the four groups were recorded, and the birth weight and thorax width of newly emerged queens were also measured. The expression levels of three genes (Vg, hex110 and hex70b) in queen ovaries were also assayed by quantitative real-time PCR (qPCR). 【Results】 The results showed that the proportion of capped queen cells with larvae in the 5 mg/kg fluvalinate group was significantly lower than those in the 0.05 mg/kg fluvalinate group, 0.5 mg/kg fluvalinate group and the control group (0 mg/kg fluvalinate), while there was no significant difference among the latter three groups. The emergence rates of reared queens in the 0.5 mg/kg fluvalinate group and 5 mg/kg fluvalinate group were significantly lower than those in the 0.05 mg/kg fluvalinate group and the control group. There was no significant difference in the birth weight and thorax width of reared queens among the four experimental groups. The results of qPCR analysis indicated that the relative expression level of Vg and hex110 in the ovary of queens reared in the 5 mg/kg fluvalinate group were significantly lower than those reared in the 0.05 mg/kg fluvalinate group, 0.5 mg/kg fluvalinate group and the control group, while there was no significant difference among the latter three groups. The relative expression levels of hex70b gene in the ovary of queens reared in the 5 mg/kg fluvalinate group and 0.5 mg/kg fluvalinate group were significantly lower than that reared in the control group, while the relative expression level of hex70b in the ovary of queens reared in the 0.05 mg/kg fluvalinate group was not significantly different from those in the other three groups. 【Conclusion】 The results indicate that the quality of reared queens of A. mellifera will be affected when the residue of fluvalinate in their food exceeds 0.5 mg/kg.

 【Aim】 To explore the chemical communication mechanism between the Asian corn borer Ostrinia furnacalis and host plants by identifying the components of volatiles from host plants used by female adults of this insect in searching for oviposition sites. 【Methods】 The oviposition preference of O. furnacalis to host plants including Polygonum lapathifolium, Abutilon theophrasti, Humulus scandens, Zea mays and Echinochloa crusgalli was screened, respectively, in field oviposition test and indoor wind tunnel behavioral test. Headspace volatiles of host plants were collected, and the components and contents of physiologically-active volatiles were identified by using two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOFMS). The electroantennogram responses of O. furnacalis to the chemical components of the extract were tested by using coupled gas chromatography-electroantennographic detection (GC-EAD). 【Results】 The field oviposition test results showed that the number of eggs laid by female adults of O. furnacalis on different plants ranked as Z. mays>P. lapathifolium>H. scandens>E. crusgalli>A. theophrasti. In the wind tunnel bioassay, the adults showed an obvious oviposition preference to H. scandens. The GC×GC-TOFMS results showed that there were 45 volatile organic compounds from H. scandens, and the relative content of terpenoids was as high as 86.29% and that of aldehydes, ketones and esters in total was only 15.83%. Nine plant volatiles, i.e., linalool, α-caryophyllene, benzaldehyde, sabinene, myrcene, 2-pentylfuran, nonanal, α-farnesene, and trans-β-ocimene, caused significant GC-EAG reaction in female adults. 【Conclusion】 There are significant differences in oviposition preference of female adults of O. furnacalis to different hosts. The physical and chemical factors of host plants are the main factors affecting the host selection. O. furnacalis shows strong preference to the volatiles of H. scandens. Nine volatiles from H. scandens, including linalool, α-caryophyllene, benzaldehyde, sabinene, myrcene, 2-pentylfuran, nonanal, α-farnesene, and trans-β-ocimenemay, play important roles in oviposition host selection for the Asian corn borer.

【Aim】 The objective of this study is to quantify the feeding preference of Hyphantria cunea to different host plants and to verify its feeding strategy based on the contents of secondary metabolites in host plants and the activities of acetylcholinesterase (AchE) and detoxification enzymes in H. cunea larvae. 【Methods】Eight plants including Morus alba, Fraxinus pennsylvanica, Ailanthus altissima, Ulmus pumila, Populus nigra, Salix babylonica, Malus micromalus and Lonicera maackii in different damaged degrees in Beijing were selected as the host plants to raise H. cunea larvae. The feeding preference of the 4th instar larvae of H. cunea to these host plants was evaluated by measuring their feeding amount, selectivity and nutritional efficiency on leaves of different host plants. The contents of flavonoids, total phenols and tannin in host plants, and the activities of acetylcholinesterase (AchE), glutathione S transferases (GSTs), carboxylesterase (CarE) and cytochrome P450 (P450) in the 4th instar larvae of H. cunea fed on leaves of different host plants were assayed. 【Results】 The 4th instar larvae of H. cunea had different selectivity to host plants, and the preference order was F. pennsylvanica and A. altissima>M. alba>U. pumila>M. micromalus, S. babylonica and L. maackii>P. nigra. The flavonoid content in host plant leaves was negatively correlated with the feeding amount of H. cunea larvae (r=-0.657, P=0.017). The larvae feeding on different plants had different nutritional efficiency. H. cunea larvae fed on L. maackii had the highest approximate digestibility (AD) (0.97%±0.01%), relatively high relative consumption rate (RCR) (2.92±0.49 g/g·d), and the lowest efficiency of conversation of ingested food (ECI) (0.005±0.01%), efficiency of conversation of digested food (ECD) (0.005%±0.008%) and relative growth rate (RGR) (0.007±0.02 g/g·d). In addition, the larvae feeding on M. micromalus had the highest RGR (0.34±0.04 g/g·d) and relatively high levels of AD (0.72%±0.10%), ECI (0.16±0.01%), ECD (0.24%±0.06%) and RCR (2.19±0.38 g/g·d). The activities of AchE, GSTs, CarE and P450 in H. cunea larvae fed on different host plants were significantly different (P<0.01). 【Conclusion】 H. cunea larvae have different feeding preference and nutritional efficiency on different host plants. Their flexible feeding strategy and detoxification mechanism may be the main reasons for strong adaptability of this insect to different host plants.

【Aim】 Egg cannibalism is common in predatory Coccinellidae. It is generally held that consumption of sibling eggs is critical to neonate larvae, but the nutritional value of non-sibling eggs cannibalized relative to prey aphids is still under debate. This study aims to examine the effect of feeding non-sibling eggs besides aphids in larval stage on the reproductive performance of female adults of Harmonia axyridis. 【Methods】Three diet treatments were set at larval stage of H. axyridis: the control (CK) with Rhopalosiphum padi aphids provided only, the dispersive egg consumption (DEC) treatment with non-sibling eggs provided in a small amount to ladybird larvae of each instar, and the aggregative egg consumption (AEC) treatment with non-sibling eggs provided in a large amount only to the final instar larvae as supplementary food together with R. padi aphids provided in the whole larval stage. The ladybird larvae with the above treatments were followed to adulthood, and the body volume of female adults, pre-oviposition period, 10-day fecundity, and egg hatching rate were surveyed. 【Results】 The diet treatment had no significant effect on the body volume of female adults of H. axyridis, which was 92.30, 89.73 and 93.98 mm³ in treatments CK, DEC and AEC, respectively. The diet treatment also had no significant effect on the pre-oviposition period, which was 7.50, 7.74 and 7.70 d in CK, DEC and AEC, respectively. The diet treatment, however, had a significant effect on 10-day fecundity. Female adults in AEC laid much fewer eggs (88) than in DEC (185) and CK (205) during the first 10 d after emergence, and no significant difference was found between DEC and CK. The diet treatment had no significant effect on egg hatching rate, which was 63.10%, 72.58% and 66.61% in CK, DEC and AEC, respectively. 【Conclusion】 These results suggest that consumption of a few non-sibling eggs across larval instars has negligible effects on reproductive performance of H. axyridis adults, but consuming a large number of non-sibling eggs at the final instar can considerably decrease its female adult fecundity.

Abstract: 【Aim】 Sperm ultrastructure has great importance for species recognition and phylogenetics of insects. Studying sperm ultrastructure in the Fulgoroidea can provide more evidence towards phylogenetic analysis which, so far, remains controversial. 【Methods】Both the spermatozoon morphology and the ultrastructure of Euricania clara Kato were observed by ultramicrotomy in combination with light and transmission electron microscopy.【Results】 Mature spermatozoa of E. clara form a sperm bundle called spermatodesm, and each individual spermatozoon has no polymorphism and consists of a head, neck and long flagellum. The head includes the apical bilayered acrosome and nucleus. The neck region is comprised of a centriole and centriolar adjunct. The long flagellum mainly consists of a pair of symmetrical D-shaped mitochondrial derivatives, a pair of fishhook-shaped accessory bodies, and axoneme with the typical 9+9+2 microtubule pattern. 【Conclusion】The characteristics of fish-hook shaped accessory bodies of E. clara are generally consistent with those of other fulgoroids known to date, but are significantly different from other auchenorrhynchans. Furthermore, the number, size, and cross-section morphology and composition of spermatozoic mitochondrial derivatives of E. clara differ significantly from those of other insects. Although there is some consistency within the suborder Auchenorrhyncha, there are obvious differences. This study provides scientific data for phylogenetic analysis of the Fulgoroidea.

 【Aim】 This study aims to realize the automatic foreground-background segmentation of lepidopteran specimen images by exploring the state-of-art computer vision technology. 【Methods】 First, the background is manually removed to form the ground truth of training set and testing set, and those images that are too large are resized to smaller ones. Then, the training set is enhanced by rotation, translation, scaling, etc., and their central areas are cropped as valid input and target images. Afterwards, the mean image of all the training samples is calculated and subtracted from all input images. Testing images are simply normalized but not enhanced. Fully convolutional networks (FCNs) are fine-tuned with training set until they converge. The parameter adjustment on later convolutional layers and de-convolutional layers is emphasized since their structures are different from those of original immigrated FCNs. When one given insect image is fed into the trained FCN after normalization, the segmentation result will be given. 【Results】 The proposed method was evaluated with the testing set including 823 samples, and the final mIoU (mean Intersection over Union) was as high s 94.96%. The visual effect of segmentation results given by FCN was much close to the manually produced results.【Conclusion】 The experimental results prove that the foregroundbackground of lepidopteran specimen images can be segmented efficiently by the trained FCN.