Condicionamento pré-imaginal no comportamento de predação, custo metabólico e perfil químico da cera das joaninhas Cryptolaemus montrouzieri Mulsant e Tenuisvalvae notata (Mulsant) (Coleoptera: Coccinellidae)

Abstract

Releasing natural enemies (parasitoids and predators) is a practice of integrated pest management. Among the predators, the lady beetles Cryptolaemus montrouzieri e Tenuisvalve notata are outstanding predators of mealybugs (Pseudococcidae). Large production of predators under standard rearing conditions may create selection pressure and alter their performance after many generations in insectaries. Therefore, we evaluated: if the lady beetles T. notata and C. montrouzieri show food preference and olfactory response to prey they were reared; if there is a metabolic cost associated with wax production in larvae of these predators; and if there is any effect of the wax chemical composition in the predator-prey interaction. Prey used were Ferrisia dasylirii and Planococcus citri. We found that the lady beetles responded similarly to volatiles released by either prey species offered. Also, there were no changes in predator behavior to prey olfactory cues. Both lady beetle species consumed more P. citri in laboratory and semi-field tests, regardless of rearing prey, indicating no pre-imaginal conditioning. Regarding the wax, there was a metabolic cost associated with its production, with a significant reduction in adult predator body weight, fecundity, and egg viability when the wax was removed during the larval stage. Finally, the predator-prey interaction does not condition the chemical composition of wax in lady beetles, as there is a difference in the chemical profiles of wax from the prey.