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Background: The cotton aphid, Aphis gossypii Glover, is a destructive insect pest worldwide; it directly or indirectly damages (virus transmission) 300 species of host plants. Knowledge of their ecologically adaptive mechanisms at the molecular level may provide an essential and urgent method to effectively control this pest. However, no transcriptome information is available for the cotton aphid and sequence data are scarce. Therefore, we obtained transcriptome data. Results: To facilitate such a study, two cotton aphid transcriptomes at different growth stages of cotton, seedling and summer, were sequenced. A total of 161,396 and 66,668 contigs were obtained and assembled into 83,671 and 42,438 transcripts, respectively. After combining the raw date for both transcriptomes, the sequences were reassembled into 66,695 transcripts, and 52,160 were annotated based on BLASTX analyses. Comparison of the transcriptomes revealed that summer presented less challenges for the cotton aphids than the seedling stage of cotton. In total, 58 putative heat shock protein genes and 66 candidate cytochrome p450 genes were identified with BLASTX. Conclusions: Our results form a basis for exploring the molecular mechanisms of ecological adaption in the cotton aphid. Our study also provides a baseline for the exploration of abiotic stress responses. In addition, it provides large-scale sequence information for further studies on this species. [ABSTRACT FROM AUTHOR]

Background: Chrysopa pallens (Rambur) are the most important natural enemies and predators of various agricultural pests. Understanding the sophisticated olfactory system in insect antennae is crucial for studying the physiological bases of olfaction and also could lead to effective applications of C. pallens in integrated pest management. However no transcriptome information is available for Neuroptera, and sequence data for C. pallens are scarce, so obtaining more sequence data is a priority for researchers on this species. Results: To facilitate identifying sets of genes involved in olfaction, a normalized transcriptome of C. pallens was sequenced. A total of 104,603 contigs were obtained and assembled into 10,662 clusters and 39,734 singletons; 20,524 were annotated based on BLASTX analyses. A large number of candidate chemosensory genes were identified, including 14 odorant-binding proteins (OBPs), 22 chemosensory proteins (CSPs), 16 ionotropic receptors, 14 odorant receptors, and genes potentially involved in olfactory modulation. To better understand the OBPs, CSPs and cytochrome P450s, phylogenetic trees were constructed. In addition, 10 digital gene expression libraries of different tissues were constructed and gene expression profiles were compared among different tissues in males and females. Conclusions: Our results provide a basis for exploring the mechanisms of chemoreception in C. pallens, as well as other insects. The evolutionary analyses in our study provide new insights into the differentiation and evolution of insect OBPs and CSPs. Our study provided large-scale sequence information for further studies in C. pallens. [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome of theChrysoperla sinicawas sequenced in this study. It is 16,057 bp in length, and contains 22 transfer RNA genes, 13 protein-coding genes (PCGs), 2 rRNA genes and 1 non-coding AT-rich region. But,C. sinicalack long tandem repeats. TheChrysoperla sinicamitogenome displays a very high level of similarity (99.27%) withChrysoperla nipponensis. The genome base composition is 39.24% A, 39.70% T, 11.98% C, and 9.08% G. Similar to other insects, all PCGs are initiated by a typical ATN codon, exceptCOX1, which starts with TCG. Nine PCGs have the standard, complete stop codon (TAA or TAG), and the other four PCGs end with the incomplete stop codon (TA or T). [ABSTRACT FROM AUTHOR]

In this study, we detected and clarified the roles of transgenic Cry1Ac+Cry2Ab cotton "639020" in controlling cotton bollworm (Helicoverpa armigera) during critical periods of bud stage (second generation of bollworm), flowering stage (third generation of bollworm) and bolling stage (fourth generation of bollworm) as well as the influences of 639020 cotton on functional response of the main predators (Chrysopa sinica larvae, Propylaea japonica, Orius and Erigonidium graminicola ) on whitefly using transgenic Cry1Ac cotton "CCRI41" and conventional cotton "CCRI49" as the control. Our results showed that the 639020 cotton well controlled the second and third generation of bollworm, and the level of insect resistance increased by 52.85% and 16.22% separately compared with that of CCRI41, with a significant effect on the second generation of bollworm. Moreover, the number of bollworm eggs in 639020 cotton field was lower than that in CCRI41 and CCRI49 cotton fields (except the second generation of bollworm) during the cotton bud, flowering and bolling stages. Although the number of bollworm larvae in 639020 cotton field was significantly lower than that in CCRI49 field, and both under the controlling index, it has no significant difference compared with that in CCRI41 cotton field. There were also no obvious changes in predator functions of Chrysopa sinica, Propylaea japonica, Orius and Erigonidium graminicola on bemisia tabaci between 639020, CCRI41 and CCRI49 cotton filed. This study evaluated the safety of new transgenic cotton on environment, anti-insect activity of exogenous gene and the safety of production and application prospect.