Augmentative Biological Control of Spider Mites on Hops

The twospotted spider mite, Tetranychus urticae (Acari: Tetranychidae), is one of the biggest challenges to hop production in Ohio.  As the production of hops is a new industry in the Midwest, research has not yet been done on the effectiveness of the pest management tactic known as augmentative biological control, where predators are released into a system to help control pest populations.  In our project, “Augmentative Biological Control of Spider Mites in Hops”, we will work with four hop growers in central and southwest Ohio to evaluate the ability of two predatory mite species, Galendromus occidentalis (Acari: Phytoseiidae) and Neoseiulus fallacis (Acari: Phytoseiidae), to successfully manage twospotted spider mite populations when released in a hop yard.  We will release these two predators at both a low and an intermediate prey density to determine at which density the predatory mites are better at managing spider mite populations.  As hop growers in the Ohio and throughout the Midwest need a cost effective pest management strategy to manage twospotted spider mites, we will compare the cost of augmentative biological control to the use of both organic and chemical pesticides currently being used.  Another key part of spider mite management is proper scouting techniques.  We will work with the same four growers to establish effective scouting programs in their hop yards.  These growers will also help us to produce extension videos that explain proper scouting techniques as well as the proper predator release techniques used in augmentative biological control.  These resources will be made available through the Ohio State Extension as well as the Ohio Hop Growers Guild.   The hop industry in the Midwest continues to grow and proper scouting techniques and the use of augmentative biological control will allow growers to improve production to keep up with the growing demands for locally produced hops.  The adoption of these tactics will be evaluated by a series of online surveys.

Expected Outcomes	Outputs	Activities	Inputs	Evaluation/Monitoring Plan, Measurement Methods
Short-term: 100 growers will learn about proper scouting techniques.   100 growers will learn about the use of augmentative biological control to control spider mites.   Intermediate-term: 20 growers will develop and use proper scouting protocols that help them to better manage their pest populations.   20 growers will incorporate augmentative biological control tactics into their pest management strategy   Supply of locally produced hops will begin to meet demand   Long-term: Profits increase   Use of augmentative biological control leads to a decrease in the use of chemical pesticides protecting the health of growers as well as increasing the presence of natural predators   Higher quality of life for growers, their families and their communities	Researched-based recommendation on the use of predatory mites G. occidentalis and N. fallacis in augmentative biological control to manage twospotted spider mites in hops   Economic analysis on augmentative biological control versus organic pesticides versus conventional pesticides   2 videos – proper scouting techniques, augmentative biological control   2 Printed Fact Sheets on proper scouting techniques, augmentative biological control   2 extension bulletins (available on OSU website and Ohio Hop Grower Guild website)   1 research article (Journal of Economic Entomology)	1 on-farm trial on four farms   2 presentations at “First Friday Hop Tours”   1 presentation at  “Ohio Hop and Malting Barley Conference and Trade Show”	SARE funding   Time - Grad Student, Advisor, and Student Research Assistant   Cooperating growers for on-farm trials	Pre and post project survey of hop grower’s pest management tactics.   Pre and post project survey of hop grower’s scouting methods.