Differential responses of Ceratitis capitata to infection by the entomopathogenic fungus Purpureocillium lilacinum

Abstract

The medflyCeratitis capitatais one of the most damaging fruit pests with quarantine significance due to its extremely wide host range. The use of entomopathogenic fungi constitutes a promising approach with potential applications in integrated pest management. Furthermore, developing insect control methods can involve the use of fungal machinery to cause metabolic disruption, which may increase its effectiveness by impairing insect development. Insect species, includingC.capitata, relies on reproduction potential, nutrient reserves, metabolic activities, and immune response for survival. Accordingly, the purpose of this study was to investigate the impacts of the entomopathogenic fungusPurpureocillium lilacinumonC.capitatapre-mortality. The medfly V8 strain was subjected to laboratory bioassays, which consisted on determining the virulence ofP.lilacinumon the medfly.Purpureocillium lilacinumwas applied on abdominal topical of 5-day-old males and females. Following the fungal inoculation, we have confirmed (i) a significant increase in tissue sugar content, (ii) a significant decrease in carbohydrase activities, digestive glycosyl hydrolase, and proteinase activities in whole midguts of treated flies, (iii) the antimicrobial peptides (AMPs) genes expression profile was significantly influenced by fly gender, fly status (virgin, mature, and mated), and time after infection, but infection itself had no discernible impact on the AMPs for the genes that were examined. This study provides the first insight into howP.lilacinumcould affectC.capitataphysiological mechanisms and provides the foundation for consideringP.lilacinumas a novel, promising biocontrol agent.