Oviposition and feeding preferences of a flower‐feeding weevil, Coelocephalapion aculeatum, in relation to conspecific damage to its host‐plant

Abstract

AbstractThe oviposition and feeding preferences of Coelocephalapion aculeatum Fall (Coleoptera: Apionidae), a host specific florivore of Mimosa pigra L. (Mimosaceae), were studied in relation to conspecific damage to its host‐plant. Adults of C. aculeatum cease ovipositing in inflorescences when the egg load reaches a number consistent with the larval carrying capacity of the inflorescence. The basis for this oviposition deterrence was examined by offering inflorescences damaged by adult feeding alone, larval feeding alone and a combination of adult feeding and oviposition. Adults preferred to oviposit on inflorescences which are not damaged by either adult feeding, larval feeding, or oviposition. No evidence for the existence of an oviposition deterring pheromone (ODP) was found. I suggest that the ability of a single host inflorescence to support the development of many larvae causes selection for the use of these oviposition deterring cues which can convey more quantitative information about the level of previous infestation than can ODPs. Adults fed a similar amount on damaged compared to undamaged inflorescences. These results assisted in the design of host range testing trials and allows predictions to be made about the effectiveness of this insect as a biological control agent.