MSOB: Predatory Mite Does Dual Duty for Biological Control

Brian German Industry, Making Sense of Biologicals

Biological Control

Using predatory mites has historically been relegated to strictly addressing other problematic insect pests. However, a new mite species has been found to provide biological control of a fungal disease impacting tomato production. Biobest R&D Director, Felix Wackers explained that the mite species Pronematus ubiquitous is the first effective biocontrol solution for tomato russet mite. But during the trials they also observed a secondary impact the mites were having on the plants.

“What we saw was in the untreated plants – the plants that did not receive the mites – they were overrun with this powdery mildew; it was really a big problem. But the plants which had been inoculated with the Pronematus, this new predatory mite, they stayed completely clean,” said Wackers. “I was stunned to see this because the only explanation we had was that somehow this mite was helping, or actively controlling this problem disease in tomato. In addition to being a solution for the tomato russet mite.”

As with other biological control approaches, the Pronematus mites are most effective as a preemptive solution to pest and disease issues. Wackers suggests introducing the mite once and allowing the beneficial biocontrol agents to build a “standing army.” Populations of the mites can be built and sustained prior to tomato russet mites or powdery mildew being present in a field. “This particular group of mites are generalist feeders. They feed on small pests, and they also feed on the hyphae, the fungi. But they also feed on pollen,” Wackers explained.

Listen to the full episode with Felix Wackers below.

‘Making Sense of Biologicals’ is a series from AgNet West that dives into various topics with unbiased experts in the field of biologics to help the industry better understand the product category.

This episode of Making Sense of Biologicals is made possible by Marrone Bio Innovations, leading the movement to environmentally sustainable farming practices through the discovery, development and sale of innovative biological products for crop protection, crop health and crop nutrition. Marrone Bio’s portfolio of 18 products helps a wide range of growers – from row crops and fruits and vegetables to tree nuts, vines, and greenhouse production – operate more sustainably while increasing their return on investment. For educational webinars and biological IPM programs, visit