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Bugs - Bug Review - University of Illinois Extension

Slug

The most common garden slug is 1-1/2 to 2 inches long when full grown and are gray to black. Slugs are not insects. They are a mollusk, like oysters, clams and snails and can be described as a snail without a shell.

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Garden slug on strawberry

Habit

Slugs are one of the first pests of spring. They hatch from jelly-like masses found under boards, flower pots and other damp areas of the garden. Slugs feed at night and leave behind a slimy residue as they move. They prefer damp, cool locations.

Damage

Slugs eat large holes in the leaves, fruits, and crowns of plants.

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Slug damage on hosta

Control

Non chemical: Slugs are difficult to control. Eliminate hiding places by removing garden debris such as leaves and mulch. Increase spacing between plants to allow better air circulation and reduce moisture that the slugs need. Hand pick at night or in early morning. Use barriers such as coarse sand or copper stripping placed around desirable plants. Attractants such as stale beer in a shallow dish may attract and trap some slugs.

Chemical: Contact your County Extension office for current pesticide controls.