Imperfect match between radiation exposure times required for conidial viability loss and infective capacity reduction attenuate UV‐B impact on Beauveria bassiana

Abstract

BackgroundUV‐B radiation represents a significant challenge for the widespread use of entomopathogenic fungi in pest management. This study focused on the research of the asynchronous response between virulence and conidial viability against Ceratitis capitata adults using specific statistical models. Moreover, it was also investigated whether the observed differences in susceptibility to UV‐B radiation in in vitro assays among three selected isolates of Beauveria bassiana were reflected in the above‐mentioned asynchrony.ResultsWhile the irradiation of the three isolates of B. bassiana was associated with a significant loss of conidial viability, their virulence was not significantly affected compared to the non‐irradiated treatments when exposed to 1200 mW m‐2 for 6 hours before or after the inoculation of C. capitata. In fact, the irradiation time needed to reduce the mortality to 50% compared to the controls was 34.69 hours for EABb 10/225‐Fil, 16.36 hours for EABb 09/20‐Fil, and 24.59 hours for EABb 09/28‐Fil. Meanwhile, the irradiation time necessary to reduce conidial viability to 50% was 9.89 hours for EABb 10/225‐Fil, 8.74 hours for EABb 09/20‐Fil, and 4.71 hours for EABb 09/28‐Fil.ConclusionThese results highlight the importance of modeling the response of entomopathogenic fungi virulence and conidial susceptibility when exposed to UV‐B radiation for the selection of environmentally competent isolates, regardless of the results obtained in previous in vitro assays on conidial germination. This strategic approach is critical in overcoming the challenges posed by UV‐B radiation and holds the key to realizing the full potential of entomopathogenic fungi in pest management.This article is protected by copyright. All rights reserved.