Research to identify vineyard plants that attract good bugs

By Terri Reddout, WSU Extension Prosser
 
 
PROSSER, Wash. – A tourist steps out of a local winery’s tasting room, takes a sip of wine, admires the blooming flowers between the long rows of grapevines and smiles. The winery owner looks at the same flowers and smiles because the vineyard’s pest problems are being controlled by natural enemies.
 
That’s the goal of Washington State University’s Vineyard Beauty with Benefits project. The research program will use native plants to beautify vineyards while also attracting beneficial insects and providing a refuge for threatened native bees and butterflies.
 
“This project has the potential to increase tourism while decreasing the need for insecticides,” said David James, associate professor of entomology, who heads the research.
 
Responding to grower requests
 
Once native shrubs, grasses and flowers are planted in and around vineyards, the project will determine which plants attract insects that eat mites, leaf hoppers and other vineyard pests.
 
Getting local vineyard managers to collaborate won’t be a problem. The impetus for the project actually came from grape growers.
 
A  beautiful vineyard attracts tourists…
and beneficial insects.

“Some vineyards were already trying to attract beneficial insects with native plants,” James said. “They were calling us because they didn’t know which plants to put in. This project will allow us to give them some answers.”

 
Drought- and mower-hardy
 
Flowering plant species produce nectar that attracts certain insects. It’s the plant’s way to ensure pollination. In turn, insects take up residence in or near the plant to drink the nectar.
 
Researchers will collect leaf samples in the field and use a microscope to count how many insects the plant attracts. Setting sticky traps, shaking the grapevine canopy and using a butterfly net will also help generate data on insect populations.
 
In addition to attracting insects, native plants need to stand up to tractors and consume little or no water.

Native plant species, like this one,
attract specific insects.
“Native plants used as cover crops need to be able to hold down the dust and to grow back after being mowed,” James said. Plants native to eastern Washington’s shrub steppe landscape are drought hardy, so they’ll be able to grow while the grapevines soak up the water through irrigation systems.
 
“Right now, yarrow and buckwheat both look like good candidates,” James said.
 
Potential for backyard gardeners too
 
The project’s bottom line benefit is to reduce growers’ spray bills.
“We’re working to increase biocontrol – using insects to control pests – so we can reduce, if not remove, the need for insect sprays,” James said.
 
The three-year project will result in a list of beneficial native plants for vineyards. The plant list potentially could benefit other crops and backyard gardeners as well.
 
“What you plant next to a vineyard and what you plant next to an apple orchard might be different depending on what pest you’re trying to control,” James said. “Backyard gardeners can plant drought-hardy native plants that save water while offering pest protection to the rest of the garden.”