Social context during ontogeny affects cannibalism and kin recognition of the predatory mite Amblyseius herbicolus (Chant) at different life stages

Abstract

Cannibalism is commonly found among phytoseiids at almost all mobile life stages. The avoidance of kin cannibalism in the presence of non-kin has been observed in limited species of phytoseiids. Early experience with conspecifics can alter individuals’ social behaviour at later stages. In this study, we examined the influence of ontogenetic isolation on the cannibalism and kin recognition of the predatory mite Amblyseius herbicolus (Acari: Phytoseiidae). Using a choice test, A. herbicolus protonymphs, deutonymphs, pre-ovipositional adults, and ovipositional adults were used as predators, and larvae (siblings versus non-kin) were given as prey. Two rearing treatments were applied to the predators to generate different social experience during ontogeny: reared in isolation or in pairs with ad libitum mixed stages of Carpoglyphus lactis (Acari: Astigmata). The results showed that social experience with siblings during ontogeny significantly reduced the cannibalism rate. Despite the social experience during ontogeny, protonymphs, deutonymphs, and pre-ovipositional adults did not discriminate kin (siblings) from non-kin during cannibalism. Only adults during oviposition showed a preference to avoid cannibalising siblings when non-kin are available. The recognition mechanism of A. herbicolus may require the contact and assessment of their eggs during oviposition. Future studies can investigate if contact with non-kin eggs and subsequently hatching larvae can influence the discrimination ability of ovipositional adults. Whether A. herbicolus can avoid cannibalising familiar kin could also be examined.