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), Carposina sasakii, and the oriental fruit moth (OFM), Grapholita molesta, 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. When we compared two pairs of PFM and OFM populations collected from the same host species and the same orchard, there is no difference in alpha and beta diversity in gut microbiota. When we compared gut microbiota of the same species and host plant from different orchards, alpha and beta diversity was different in populations of PFM collected from two pear orchards but not in other comparisons. Our study suggests that the two pests share many features of gut microbiota and environment in orchards is a main factor influencing their gut microbiota.

The Asian ladybeetle, Coccinella septempunctata, is an important insect of predatory natural enemy, which has a strong control effect and application prospects for aphids, whiteflies, mealybugs, and other small-sized pests of agriculture and forestry crops. Gut microbiota composition posed impacts on development of insects. In order to clarify the effect of artificial feed feeding on the intestinal microbial species and structure of C. septempunctata, we compared the intestinal microbial flora of C. septempunctata reared on bean aphids and artificial food for 15 days. Results show that Proteobacteria was the dominant component in all groups at phylum level, Rhodobacter, Methylovigula, Burkholderia, and Bradyrhizobium were the dominant bacteria among all groups at genus level. As to the differences in bacterial community structure and diversity, there is no significant difference between Shannon index and Simpson index, the principal components analysis of the bacterial communities, and the samples were roughly distributed in different regions. After 15 days of feeding, artificial diet did not significantly reduce the microbial diversity of the gut of C. septempunctata compared to the aphid group, and there was no significant effect on the abundance of dominant flora in the gut of C. septempunctata, C. septempunctata gut has a similar core microbiota. This study clarifies the effects in intestinal microbial diversity and composition structure of the C. septempunctata with artificial diet, and provides a theoretical basis for understanding the intestinal microorganisms and optimizating the artificial diet of C. septempunctata.

The hoverfly, Eupeodes corollae, is a worldwide natural enemy of aphids and a plant pollinator. To provide insights into the biology of this species, we examined its population genetic structure by obtaining 1.15-GB random genomic sequences using next-generation sequencing and developing genome-wide microsatellite markers. A total of 79,138 microsatellite loci were initially isolated from the genomic sequences; after strict selection and further testing of 40 primer pairs in eight individuals, 24 polymorphic microsatellites with high amplification rates were developed. These microsatellites were used to examine the population genetic structure of 96 individuals from four field populations collected across southern to northern China. The number of alleles per locus ranged from 5 to 13 with an average of 8.75; the observed and expected heterozygosity varied from 0.235 to 0.768 and from 0.333 to 0.785, respectively. Population genetic structure analysis showed weak genetic differentiation among the four geographical populations of E. corollae, suggesting a high rate of gene flow reflecting likely widespread migration of E. corollae in China.

The ladybeetle Coccinella septempunctata Linnaeus is an important natural enemy of aphids, scale insects, whitefly, and lepidopteran larvae. Mass rearing of this natural enemy is limited due to the lack of effective artificial feed. We compared the biological performance of C. septempunctata, reared on four artificial diets (A, B, C, and D), while the pea aphid Aphis craccivora served as a control treatment (CK). Results showed that the developmental time before emergence ranked from short to long follow as: CK (12.30d)<D (16.66d)<A (17.38d) B (80.00%) > A (57.50%), and new adult weight from high to low follow as: CK (339.50 g*0.0001) > A (205.33 g*0.0001) > D (197.68 g*0.0001) > B (174.89 g*0.0001) > C (169.46 g*0.0001). The ratios of fecundity between the experimental group and the control group were 80.46% (A), 39.24% (B), 45.31% (C), and 53.02% (D). The hatch rates were 59.50% (A), 46.00% (B), 57.65% (C), 54.50% (D), and 53.88% (CK). The mortality of C. septempunctata adults fed on a combined artificial diet was higher than those fed on the control diet. Compared to the control diet, C. septempunctata did not significantly reduce oviposition when fed on artificial diet A. Therefore, diet A can be used in mass‐rearing of C. septempunctata.

Haplodiplatyidae is a recently established earwig family with over 40 species representing a single genus, Haplodiplatys Hincks, 1955. The morphology of Haplodiplatyidae has been studied in detail, but its molecular characters remain unclear. In this study, two mitogenomes of Haplodiplatys aotouensis Ma & Chen, 1991, were sequenced based on two samples from Fujian and Jiangxi provinces, respectively. These represent the first mitogenomes for the family Haplodiplatyidae. The next-generation sequencing method and subsequent automatic assembly obtained two mitogenomes. The two mitogenomes of H. aotouensis were generally identical but still exhibit a few sequence differences involving protein-coding genes (PCGs), ribosomal RNA (rRNA) genes, control regions, and intergenic spacers. The typical set of 37 mitochondrial genes was annotated, while many transfer RNA (tRNA) genes were rearranged from their ancestral locations. The calculation of nonsynonymous (Ka) and synonymous (Ks) substitution rates in PCGs indicated the fastest evolving nd4l gene in H. aotouensis. The phylogenetic analyses supported the basal position of Apachyidae but also recovered several controversial clades.

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. Importance: Understanding 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.