The entomopathogenic fungus Conidiobolus coronatus has similar effects on the cuticular free fatty acid profile of sensitive and resistant insects

The mechanisms underlying recognition of a susceptible host by the fungus, and the role of cuticular compounds (CCs) in this process, remain unclear; however, accumulated data suggest that it is influenced to a great degree by cuticular lipids. Two insect species differing in their sensitivity to fungal infection, viz. the highly-sensitive Galleria mellonella (Lepidoptera, Pyralidae) and resistant Calliphora vicina (Diptera, Calliphoridae), exhibited significant qualitative and quantitative changes in cuticular free fatty acid (FFA) profiles after exposure to Conidiobolus coronatus (Entomopthorales). Despite being systematically distant, leading different lifestyles in different habitats, both insect species demonstrated similar changes in the same FFAs following exposure to the fungus (C12:0, C13:0, C14:0, C15:0, C16:1, C16:0, C18:1, C18:0), suggesting that these are involved in the contact-induced defense response As it was not possible to distinguish the share of FFAs present in the conidia that were attached to the cuticle from the FFAs of the cuticle itself in the total amount of extracted FFAs, further research is necessary.