Presence and biology of astigmatid mite species in biological control products with predatory mites on the Dutch market

In 2025, the COGEM issued advice on containment measures for the use of biological control agents in PKb-I greenhouses with genetically modified (GM) plants. It was noted that products containing predatory mites also contain so-called prey mites, which serve as food for the predatory mites. Because it was unclear whether these prey mites pose a risk for the spread of pollen when used in a greenhouse with GM plants, COGEM commissioned research into the presence of prey mite species in products containing predatory mites.

The results of the research are described in the report ‘Presence and biology of astigmatid mite species in biological control products with predatory mites on the Dutch market’. For fifteen representative products, the presence of prey mites was investigated and the species was determined. In addition, for all identified prey mites, a literature study was performed to gain insight into their behavior, with a focus on the possibility of coming into contact with pollen.