Maternal age and density shape offspring foraging strategies in a predatory mite.

Abstract

Maternal effects are key drivers of offspring phenotypic plasticity, influencing traits such as survival, growth, and behavior. Maternal age at oviposition is an intrinsic factor governing such effects, which often exerts negative impacts on offspring traits. However, in the thelytokous predatory mite <i>Amblyseius herbicolus</i>, offspring of older mothers exhibit increased growth efficiency and reduced prey consumption. The proximate mechanisms of this inverse Lansing effect remain elusive, but this conservative offspring' foraging strategy may reflect an anticipatory maternal response to mitigate intraspecific competition among later-produced offspring. Here, we investigated how maternal age at oviposition and maternal rearing density influence offspring foraging strategies. Eggs (ie offspring) were collected from mothers maintained under low- and high-density conditions and classified as Young or Old based on maternal age at oviposition. Offspring were then assessed for immature survival under low prey availability, prey consumption, predation incidence, latency to attack prey, and superfluous killing. Offspring of older mothers showed reduced prey consumption and lower predation incidence, whereas offspring of high-density mothers had higher survival under prey limitation. Maternal density partially modulated age-related effects. Our findings highlight the role of maternal effects in shaping adaptive foraging strategies and demonstrate that maternal influences can induce risk-averse behavioral changes in response to ecological conditions. Both intrinsic and extrinsic maternal factors shape offspring behavioral strategies, and maternal age, in particular, can serve as a dynamic source of variation influencing predator-prey interactions and population dynamics.