Diversity of Ichneumonoidea in native forest and cassava crop environments in the Western Amazon
TL;DR
While cassava agroecosystems support high abundances of specific taxa, adjacent native forests serve as critical reservoirs for broader parasitoid diversity, indicating that while cassava agroecosystems support high abundances of specific taxa, adjacent native forests serve as critical reservoirs for broader parasitoid diversity.
Abstract
Abstract Parasitoid Hymenoptera are key natural enemies of insect pests, playing an essential role in ecological balance and pest control in agroecosystems. Ichneumonoidea is the largest superfamily in the order, but its diversity in the Amazon rainforest remains understudied. This study aimed to assess the diversity of Ichneumonoidea parasitoids in native forest and cassava crop environments in Mâncio Lima, state of Acre, Brazil. Sampling was conducted using Malaise traps installed in forest and cassava areas over three 15-day periods between December 2020 and April 2021. Specimens were sorted and identified at family and subfamily levels under a stereomicroscope. A total of 1,649 Ichneumonoidea individuals were collected, comprising 32 subfamilies (15 Ichneumonidae and 17 Braconidae). Native forests exhibited significantly higher Ichneumonidae richness and Shannon diversity (H') than cassava croplands (p < 0.05). This structural shift was driven by the dominance of Cremastinae in agricultural areas. While Braconidae community composition remained similar across habitats, croplands were characterized by a highly female-biased sex ratio (88%). These results indicate that while cassava agroecosystems support high abundances of specific taxa, adjacent native forests serve as critical reservoirs for broader parasitoid diversity.