Apple Integrated Mite Management: where can we go next?

Authors: BERGERON, PAUL - Washington State University; Moretti, Erica; JONES, CAMDEN - US Department Of Agriculture (USDA); THOMPSON-ARCHER, KELLY - US Department Of Agriculture (USDA); Rehfield-Ray, Linda; Cooper, William - Rodney; Schmidt, Rebecca

Submitted to: Western Orchard Pest and Disease Management Conference
Publication Type: Abstract Only
Publication Acceptance Date: 11/29/2021
Publication Date: N/A
Citation: N/A

Interpretive Summary: Predatory mites are critical predators for controlling pest spider mites in apple orchards. There is a program dedicated to spider mite management that is based on saving predatory mites through only using pesticides that cause minimal harm to the predators. Due to changing management practices, new predatory mites are becoming more common. Researchers at the USDA-ARS in Wapato, WA and Washington State University studied the harmful effects of pesticides on a new predatory mite that could improve this pest management program. The researchers also looked at what predatory mites feed on during the growing season to find ways to improve predator populations in orchards. The two main species of apple predatory mites only differed slightly in pesticide tolerance, so only small changes need to be made to the current pest management plan. The predatory mites also ate pollen throughout the growing season, so providing pollen as a food source year-round may increase their numbers. These findings will update the current management plan to allow for more control of pest mites by saving more predators

Technical Abstract: Integrated mite management is one of the most successful biocontrol programs in perennial cropping systems, focusing on the conservation of Galendromus occidentalis and the use of pesticides known to be relatively safe to this predator. After 50 years, integrated mite management is still effective, but the ecology of apple orchards has changed as pesticide use shifts from broad spectrum to more selective products. Pest species are also changing and there is a new-to-us predatory mite, Amblydromella caudiglans, that is increasing in presence and dominance around Washington state. This predator has a completely different habitat and diet preference, opening the possibilities for integrated mite management. Here, we examine and compare the nontarget effects of orchard pesticides on Amblydromella caudiglans and Galendromus occidentalis. We also examine the pollen and pest resource use of a predatory mite community. This work found that there are minimal differences in pesticide nontarget effects between Amblydromella caudiglans and Galendromus occidentalis. For this reason, slight changes can be made to current integrated mite managements plans that allow for the incorporation of both major apple predatory mites. Also, this work has shown that pollen is an important resource throughout the growing season for predatory mite communities and future work should investigate pollen supplementation programs. This work provides the foundation for the next generation of integrated mite management to shift away from a single species management plan in favor of a multi-species, community level conservation plan