By Allison Matthews

MISSISSIPPI STATE -- Good and bad insects in the garden may look all the same to some growers, but understanding differences between bugs can help prevent vegetable losses.

James Jarratt, entomology specialist with Mississippi State University's Extension Service, said different types of bugs perform different functions in gardens. Some, like earthworms, are helpful because they aerate the soil and convert unusable materials into something plants can utilize. Others, including many types of moth larvae, feed on vegetable plants and are detrimental to gardens.

Jarratt said earthworms and insects that may look like worms are two totally different types of creatures. The larvae of moths often look like worms because they are elongated and crawl like worms, but they are actually insects. Insect larvae usually pose the greatest threat to garden yields.

"Gardeners have several insects that can damage their vegetables. These include the tomato fruit worm, tomato horn worm, cabbage looper and the squash vine borer," Jarratt said.

The average tomato grower in Mississippi is more likely to see damage from the tomato horn worm, which only feeds on tomatoes, than the tomato fruit worm, which also likes corn.

The cabbage looper feeds on many types of greens, including cabbage, lettuce, turnip greens and broccoli. Jarratt said this insect becomes less of a problem as the weather heats up because the green vegetables go out of season.

In addition to the many larvae insects that damage gardens, beetles also pose a threat.

"There are a number of beetles that feed on the foliage of peas and beans. They often leave holes in the leaves of these vegetable plants, but most of the time they do not do enough damage to be concerned about," Jarratt said.

Many gardeners become nervous when they notice holes eaten away in their vegetable plants, but the insects may not feed on the vegetables themselves. The spotted cucumber beetle and the bean leaf beetle are two insects that usually do not threaten vegetables, but do feed on the plants' leaves.

Jarratt said if gardens have harmful pests, the insects will leave signs that growers can detect.

"If you have problem pests, you are going to notice some type of damage in the fruit itself or on the leaves of the vegetable plant. For example, there will be holes in your cabbage leaves if you have cabbage loopers," he said.

But hope for vegetable growers can be found in a bottle at any local plant store. Jarratt said insecticides are available to safely guard against most garden pests.

"Always be sure whatever kind of spray you are using is cleared for use on vegetables," Jarratt said. "Some chemicals are intended to protect flowers from pests and may not be safe to use on foods."

Jarratt added that some vegetable-safe insecticides can be bought combined with fungicides to help prevent plant diseases as well.