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Fact Sheets - Soil Insect Pests of Vegetables

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Pest Management Fact Sheet #5045

Soil Insect Pests of Vegetables

James F. Dill, Pest Management Specialist
Clay A. Kirby, Insect Diagnostician

For information about UMaine Extension programs and resources, visit extension.umaine.edu.
Find more of our publications and books at extensionpubs.umext.maine.edu.

Description & Biology

The following are the most significant soil insects attacking home garden plants.

Wireworms are the immature stage (larvae) of the click beetle. Wireworms are cylindrical, about 1-1/2 inches long, brownish to yellow and are rather hard-bodied. These insects eat seeds, cut into small shoots and often bore into stems, roots, and tubers. They attack many vegetables including potatoes, onion, corn, carrots, peas, beans, and melons.

Wireworm (Larvae)

Wireworm (Larvae)

Wireworm Feeding on Potato

Wireworm Feeding on Potato

Click Beetle

Click Beetle

White grubs are whitish, C-shaped larvae with brown heads. They include the immature stage of European chafers, Japanese beetles, and beetles from the genus Phyllophaga (May beetles/June bugs). They stay in the soil and feed on the roots of corn, beans, peas and other vegetables. They are most likely to damage plants in or near ground that was recently sod covered.    

White Grub

White Grub

Adult European Chafer Beetle

Adult European Chafer Beetle

Adult Japanese Beetle

Adult Japanese Beetle

Adult May Beetle/June Bug

Adult May Beetle/June Bug

Cutworms are the larval, or immature, stage of certain moths. They can often eliminate a stand of plants in a garden. Cutworms are night feeders and are seldom seen during the day. These insects cut off small plants at or near the ground level and feed on the tender stem. Some types climb up the stem and feed on foliage.  Many plants are attacked by cutworms, but they are especially damaging to corn, beans, tomatoes and peppers.

Cutworm Feeding on Potato Stem

Cutworm Feeding on Potato Stem

Seed corn maggots are the larvae of small flies. They develop in the soil and feed on seed and seedlings of corn, beans, peas, potatoes, cabbage, melons and other crops. (No pictures available at this time)

Cabbage maggots are also the larvae of small flies. They feed on the surface of roots and tunnel through them. They attack cabbage, broccoli, turnips and other similar crops. Other maggots which attack vegetable crops are the carrot rust fly and the onion maggot.

Cabbage Maggots and Pupae

Cabbage Maggots and Pupae

Management

Beneficial nematodes can be used for controlling the soil dwelling larval stages of the above pests. Cardboard plant collars, Spinosad, Bt (Bacillus thuringiensis), and carbaryl (Sevin) sprays and baits can be used to control cutworms.


When Using Pesticides

ALWAYS FOLLOW LABEL DIRECTIONS!

Pest Management Office
491 College Avenue, Orono, ME 04473-1295
1-800-287-0279 (in Maine)


Information in this publication is provided purely for educational purposes. No responsibility is assumed for any problems associated with the use of products or services mentioned. No endorsement of products or companies is intended, nor is criticism of unnamed products or companies implied.

© 2010, 2013
Published and distributed in furtherance of Acts of Congress of May 8 and June 30, 1914, by the University of Maine Cooperative Extension, the Land Grant University of the state of Maine and the U.S. Department of Agriculture cooperating. Cooperative Extension and other agencies of the U.S.D.A. provide equal opportunities in programs and employment.

Call 800-287-0274 or TDD 800-287-8957 (in Maine), or 207-581-3188, for information on publications and program offerings from University of Maine Cooperative Extension, or visit extension.umaine.edu.


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