A predatory mite as potential biological control agent of the invasive Thrips parvispinus

Thrips are one of the most damaging and economically costly pests in agricultural crops. Thrips parvispinus is an invasive species which has recently spread across Europe. It is a polyphagous pest that infests both vegetable and ornamental crops. At present, the use of biological control against T. parvispinus is at its infancy. Here, we tested the potential of predatory mites as biocontrol agents of T. parvispinus. We evaluated the predation and oviposition rates of two predatory mites, Amblyseius swirskii (Athias-Henriot) and Euseius degenerans (Berlese), when offered first instar larvae of T. parvispinus and found that predation and oviposition rates of A. swirskii were higher than those of E. degenerans. Furthermore, A. swirskii had a higher juvenile survival and developmental rate when provided with pollen or a diet of pollen with thrips larvae than when provided with a diet of thrips larvae alone. A small-scale greenhouse population experiment on isolated sweet pepper plants showed that A. swirskii effectively controlled T. parvispinus, both with and without the supply of pollen as alternative food for the predators. Our results confirm that releasing A. swirskii before pest invasion can efficiently control T. parvispinus populations on sweet pepper.