Infection by Nosema sp. alters the morphological parameters and flight capacity of Cotesia flavipes

Abstract

Cotesia flavipes (Cameron) (Hymenoptera: Braconidae) is the main biological control agent (BCA) of the sugarcane borer Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae). However, the quality of parasitoids is compromised by contamination from the pathogen Nosema sp. (Microsporidia: Nosematidae), which affects biological parameters, including the host search capacity of this BCA. In addition, studies have indicated a reduction in the flight activity and dispersal of C. flavipes over the years. Thus, the objectives of this study were to determine whether the decreased flight capacity of this parasitoid could be associated with infection of D. saccharalis larvae by Nosema sp. and to assess changes in the morphology and deformity of the wings of parasitoids infected by this pathogen. In this study, such changes were assessed in parasitoids obtained from uninfected larvae of D. saccharalis and larvae infected with 10, 102, or 103Nosema spores per larva. A significant reduction in the flight capacity and differences in the morphology of C. flavipes were detected, as were deformities in the wings of the parasitoid, especially when C. flavipes was reared in larvae infected with a dose of ≥ 102 spores per larva. These results indicate that infection by microsporidia leads to deleterious effects that compromise the flight activity of C. flavipes, which may impact the effectiveness of this parasitoid in biological control programs for sugarcane borer management.