Organic Farming Shapes Population Dynamics and Genetic Diversity of Euborellia annulipes in Banana Groves.

Organic farming can help mitigate the negative impacts of agriculture on biodiversity, but its effects remain controversial and poorly understood for many taxa, especially from a genetic perspective, where major knowledge gaps persist. This study investigates how the organic and conventional management of banana groves influences population dynamics (i.e., total abundance and abundance by sex and developmental stage) and mitochondrial genetic diversity (cytochrome b gene) of the earwig Euborellia annulipes, a natural biological control agent. The results revealed higher overall abundance, particularly of females, in organic groves. This could be due to females' more sedentary behaviour linked to parental care, increasing their vulnerability to local disturbances such as pesticide application. In contrast, males, being more mobile, did not respond to the farming system. Genetic analyses revealed similar haplotypic diversity across systems but higher nucleotide diversity in conventional orchards. This may suggest either pesticide-induced mutations associated with detoxification and resistance or increased gene flow driven by greater mobility in response to disturbance. Although the high genetic diversity observed raises questions about the introduced status of E. annulipes, its origin remains unresolved. These findings highlight the relevance of integrating ecological and genetic data when assessing the impacts of agricultural practices on beneficial arthropods.