Feb 13, 2019

Beneficial insects useful for Georgia greenhouse crops

While the use of beneficial insects and other biocontrols for agricultural pest management hasn’t gained widespread usage in open field production, some Georgia farmers are using natural control methods in greenhouse and high-tunnel production.

“The makeup of our farms and the perceptions of our farmers determine what biological controls we can use, if any,” said Tim Coolong, University of Georgia associate professor of horticulture, at a daylong continuing education session for green producers on beneficial insects at the Georgia Green Industry Association’s Wintergreen 2019 conference held Jan. 23-25 in Duluth, Georgia. “We are very aware of the role of beneficial (insects) and predators out there. Many new pesticide chemistries are very specific in what they are targeting, which is important as there is continuing concern about pollinator health and trying to manage insecticides carefully.”

The scale and the potential for incidental damage to crops limit the usefulness of beneficial insects in the production of some vegetable crops, however.

“Introducing biological agents to the farm is playing a larger role in the vegetable industry, but strictly using beneficials in large-scale outdoor fields isn’t common,” Coolong added. “There is zero tolerance from buyers for (insect) damage in many of our vegetable crops, and because of these tolerances, we’ve been limited in using beneficial insects on a large open-field scale.”

While many commercial growers use biopesticides in conjunction with traditional synthetic chemistries in outdoor field production, the use of beneficial insects for pest control is rising among producers using high tunnels and greenhouses.

“We’ve seen a lot more success in protected structures,” Coolong said. “For outdoor production it is much more about managing the farmscape in a way that brings in more natural beneficial insects by providing the right habitat for natural predators. At this time, the focus has not been so much about releasing biologicals, but on how to improve your farm with cover cropping and rotational crops that enhance the habitat for beneficial insects.”

Practices such as strip-tillage preserve the habitat for beneficial insects and natural predators, as does planting cover or rotational crops like clovers, buckwheat, cereals and wildflowers, which also benefit pollinators.

For more about controlling plant pests through biological control, contact your local UGA Cooperative Extension agent at 1-800-ASK-UGA1.

– Maria M. Lameiras, University of Georgia Extension