Predation capacity of two thrips species on predatory mite eggs

Abstract: Predatory mites of the family Phytoseiidae are among the most commonly used
predators for biological thrips control. Mite species like Amblyseius swirskii, Transeius
montdorensis or Neoseiulus cucumeris are widely used to control thrips populations such as
Frankliniella occidentalis or Thrips tabaci. However, some polyphagous thrips species are able to predate on predatory mite eggs, potentially affecting the efficacy of biological control
strategies. As new invasive thrips species regularly arrive in Europe, it is therefore important to look at their predation capacity against phytoseiid predatory mites. In this study, we investigated the predation capacity of two invasive thrips species, Thrips parvispinus and Thrips setosus, on eggs of the predatory mites A. swirskii and T. montdorensis, respectively. We looked at the predation rates of 2 thrips life stages over 48 h: adult females and L2 larvae. We observed that T. parvispinus and T. setosus adult females did not eat any A. swirskii or T. montdorensis egg. However, T. parvispinus larvae ate 0.83 A. swirskii eggs and T. setosus larvae ate 0.73 T. montdorensis eggs in average in 48 h. These results show a limited predation capacity of T. parvispinus and T. setosus on phytoseiid mite eggs.