Cao, L.-J. | bioRxiv Science

bioRxiv2020

The oriental fruit moth genome provides insights into evolutionary adaptation of tortricid pests

Moths of the family Tortricidae (Insecta: Lepidoptera) usually distribute in temperate and tropical high upland regions. The oriental fruit moth (OFM) Grapholita molesta is a globally important pest of stone and pome fruit from this family. In this study, we assembled a chromosome-level genome for the OFM and conducted a comparative genomic analysis with other lepidopterans. This genome was assembled to 28 chromosomes with a size of 517.71 Mb, an N50 of 19.5 Mb, and a BUSCO completeness of 97.1%. In total, 19968 protein-coding genes were predicted, among which 15269 were functionally annotated. We manually annotated ten gene families for 13 representative genomes from the Lepidopteran. In general, two tortricid moths have a moderate number of detoxification and receptor genes and the lowest number of HSP genes, congruent with their polyphagous dietary and pattern of distribution. However, the OFM has the highest number of P450, I Rs and ORs among all species. Compared to the other tortricid species of the codling moth Cydia pomonella, the OFM has more genes in all gene families. Our results indicate that the high number of some detoxification and receptor genes may be related to the strong adaptation of OFM as a global pest. The high-quality genome of OFM provides an invaluable resource for understanding the ecology, genetics, and evolution of tortricid moths.

genomics↗

bioRxiv2020

Similar gut bacterial microbiota in two fruit-feeding moth pests collected from different host species and locations

Numerous gut microbes are associated with insects, but their composition remains largely unknown for many insect groups, along with factors influencing their composition. Here, we compared gut bacterial microbiota of two co-occurring agricultural pests, the peach fruit moth (PFM) and the oriental fruit moth (OFM), collected from different orchards and host plant species. Gut microbiota of both species was mainly composed of bacteria from Proteobacteria, followed by Firmicutes. The two species shared bacteria from the genera Pseudomonas, Gluconobacter, Acetobacter, and Pantoea, although endosymbiotic Wolbachia was the most abundant genus in PFM and Lactobacillus was the most abundant in OFM. PFM tended to have lower diversity and richness of gut microbiota than OFM; however, only some of the comparisons were statistically significant. Orchards can influence gut microbiota in terms of richness, particularly for PFM, but not so much for diversity parameters. Functional prediction of gut microbiota showed that the top pathways are amino acid metabolism, translation, and membrane transport in both species, but their abundance varied between the two moth species. These results show that two fruit moths share many features of gut microbiota, and the bacterial species are relatively stable within moth species even when they use different host plants. Our study suggests that fruit-feeding behavior may play a role in shaping gut microbiota of the two fruit moths, which may provide microbial targets for pest control. ImportanceUnderstanding the associated microbes with insects can point to new targets for pest control. Here we compared bacterial community in the gut of two co-occurring agricultural pests, the peach fruit moth (PFM) and the oriental fruit moth (OFM), collected from different orchards and host plant species. We found that the bacterial genera Pseudomonas, Gluconobacter, Acetobacter, and Pantoea are abundant and shared in two moths. The composition of the bacterial species is relatively stable within moth species even when they use different host plants, indicating that the gut microbiota community in the PFM and OFM is likely to be related to their fruit-feeding behavior. The findings have implications for developing novel pest control approaches by targeting gut microbes associated with the two moths.

microbiology↗