Yunjiao Guo

Hornets, which constitute part of the subfamily Vespinae, are widely distributed social wasps, and some species have been documented as invasive in many pa

Social wasps, including hornets, are increasingly recognized not only as invasive pests but also as farmed insects; however, their gut microbiota and associated diseases remain poorly characterized. In indoor rearing facilities for the hornet Vespa analis in Dehong, Yunnan, China, we observed recurrent larval disease with weakness, larvae falling from the nests, and high mortality. To identify the causative agent and its effects on the gut community, we isolated bacteria from diseased larvae, characterized them by morphology, biochemical tests, and 16S rRNA gene sequencing, and then established an oral infection model. A red-pigmented isolate, designated YR2, was identified as Serratia marcescens. Oral inoculation with YR2 reproduced disease signs and significantly increased larval mortality, and a phenotypically consistent S. marcescens isolate was reisolated from infected larval guts. Amplicon sequencing showed that healthy larvae harbored gut communities dominated by Proteobacteria, whereas infection was associated with reduced diversity and a dysbiotic shift with enrichment of Enterobacterales. Our results support S. marcescens as a strong candidate pathogen associated with larval disease and mortality in Vespa analis under indoor-rearing conditions. Our findings provide a basis for pathogen surveillance and microbiota management in indoor hornet husbandry, and support improved biosecurity and health monitoring practices.

The potato tuber moth Phthorimaea operculella is a serious boring pest of potato. An integrated ecological approach to sustainable pest management is necessary for the control of this species. This study investigated the effects of minced leaves and plant extracts of Eryngium foetidum on the oviposition behavior of PTM females. The behavioral regulatory components of PTM females in response to the extracts were determined using chemical analyses and electrophysiological tests. Individual electroantennographic detection (EAD)-active compounds and mixtures were evaluated using oviposition choice bioassays. The results indicate that minced leaves had a deterrent effect on oviposition. The extracts at low dosages had an attraction effect, while high dosages had a repellent effect on the oviposition of PTM adult females. The dominant compounds of the extracts were trans-2-dodecenal and trans-2-tridecenal and showed EAD activity. trans-2-dodecenal, trans-2-tridecenal and their mixtures showed significant oviposition-repellent effects toward the PTM. The oviposition stimulation indices (OSIs) of trans-2-dodecenal and trans-2-tridecenal were −100% and −94.03% at 10 mg/mL, respectively. The OSIs of mixtures at natural ratios of 10 mg/mL and 5 mg/mL were −95.11% and −90.96%, respectively. The results can be used for the further development of ecological control strategies for this pest species.