2006-08-23 / Agriculture

Beneficial bugs naturally eliminate pests

By Sharon Omahen

About 50 men and women crowded around University of Georgia entomologist Kris Braman as she demonstrated how quickly a pair of tiger beetles attack and devour an armyworm. The group's attraction wasn't just morbid curiosity.

Georgia golf course and landscape industry professionals spend millions of dollars each year controlling armyworms and other caterpillars, so they were rooting for the beetle.

Braman's research focuses on controlling insects that feed on Georgia turfgrasses and ornamental plants. Her subjects include fall armyworms, Japanese beetles, chinch bugs and two-lined spittle bugs.

Using a predator, like the tiger beetle, to control a pest is called biological control. This method allows farmers and home owners to control insect pests without spraying insecticides.

Over the next four years, Braman will monitor how well the tiger beetles keep armyworm and Japanese beetle grub populations down in her research plots.

"These beetles aren't being used much in this way, but they are very abundant in nature," she said. "We have been finding them more and more in our insect pitfall traps."

Using beneficial insects isn't a new concept to the greenhouse and field crop industries, but it is new to the turfgrass industry.

"The (beneficial insects) that are commercially available are not widely used in turf," Braman said. "We're finding that the ones used in greenhouses do occur in turf."

Many greenhouse growers buy beneficial insects to control pests on their plants. One of the most popular, the minute pirate bug, feeds on insect eggs, caterpillar eggs, thrips, mites and small larvae, Braman said.

One of Braman's favorite beneficial insects is the bigeyed bug. It feeds on softbodied small insects like armyworms, cut worms and chinch bugs.

"We ought to be looking in this direction as a possibility, if it's cost effective," Braman said. "It's a matter of conserving the predators that are already there and using management practices that don't eliminate the natural enemies."

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