Loss of parasitoid diversity in China’s corn agro-ecosystem over a 30-year time period

Globally, insect abundance and diversity are experiencing a rapid decline. Despite important inter-taxa geographical variability, this can entail an extinction of ecological interactions decay ecosystem functions. In study, we compared the spatial distribution, species composition Trichogramma spp. egg parasitoids (Hymenoptera: Trichogrammatidae) over 30-year time period in China. During 1980s 2016–2018, masses Asian corn borer (ACB), Ostrinia furnacalis, were systematically sampled from fields across country. 2018, five identified with ostriniae representing 90% complex. Since 1980s, two new have made their appearance while nine (out 12; i.e., 75%) disappeared. These include comparative specialists but also generalists such as T. evanescens exiguum. Across sites, richness (R) (Shannon-Weiner index) declined by respective 25–86% 56–100% (except for Heilongjiang province) frame. We hypothesize that is attributed to land use change, pesticide plant decline agro-landscapes. Conversely, no negative impacts detected augmentative biological control. Given drastic reduction ACB parasitoid richness, agro-ecological measures diversification strategies should be deployed restore resilience local farming systems. Our work carries major implications food security helps muster support more nature-friendly, pest-resilient systems China abroad.