Unintended consequences: the adverse effects of royal jelly supplementation in the predatory mite Amblyseius herbicolus Chant (Acari: Phytoseiidae)

In this study we delved into the effects of royal jelly supplementation on the life history traits of Amblyseius herbicolus, a thelytokous predatory mite with potential in biological pest control. Royal jelly, a nutrient-rich substance from honeybees, is known for its diverse biological activities in various species. Our experiments showed the concentration-dependent impacts of royal jelly supplementation on A. herbicolus. While royal jelly positively influenced mite survival at low concentrations (5%), a trade-off emerged: increased survival came at the cost of reduced fecundity. Also, royal jelly reduced ovipositional and post-ovipositional duration. Remarkably, maternal royal jelly supplementation influenced the pre-ovipositional duration of A. herbicolus offspring, suggesting transgenerational effects. However, certain traits, such as developmental time, size at maturity, and lifespan of both parents and offspring, remained unaffected. Our findings emphasise the specificity of royal jelly's impact on different aspects of mite biology and the possibility of inducing adverse influences on life history traits. To fully harness the potential of royal jelly in dietary supplementation, further research exploring the molecular mechanisms underlying these interactions is imperative.