SLUGS AND SNAILS

Philip J. Hamman*

Slugs and snails can be troublesome around the home, garden and in greenhouses. These members of the mollusk family eat plants and leave glistening trails of slime wherever they crawl. Their soft bodies and slimy appearance make them repulsive to many people.

Description

Both slugs and snails have fleshy, soft, slimy, legless bodies that range in color from whitish-yellow to black; most are mottled with shades of gray. Their eyes are carried on the ends of stalks or appendages on the head. These pests are slow moving and grow to lengths of about ½ inch to 4 inches (1.25 cm to 10 cm).

Snails have a hard spiral shell on their backs. Shells range from about 1/4 to 1 inch (0.62 cm to 2.5 cm) in diameter, and are off-white to brown or black in color. Snail shells provide protection from predators and during periods of excessive heat and dryness.

Both slugs and snails are able to move easily over almost any object, and are afforded some protection
from the elements by mucus which is constantly secreted.

Biology and Habits

Photo Courtesy of Dr. Jim Baker - North Carolina State University

Slugs and snails lay masses of 25 to 100 or more eggs in the soil. Slug eggs resemble little balls of jelly and are very tough and resistant to heat, cold and drying. Under favorable conditions eggs will hatch in about 1 month. Immediately upon hatching the young begin to feed and can reach sexual maturity in three to five months. Those hatching in the spring can begin egg laying in the fall. There is a tendency for young slugs and snails to stay close to the place where they were hatched and return there each morning. Some snails may take 2 years to become full grown.

Slugs and snails require moisture for survival. They normally hide during the day to avoid the sun and can be found under pieces of wood, plants, pottery, rocks, fallen leaves or mulch. They are active at night or on damp, dark days.

These pests feed on leaves, flowers, stems or roots of plants by scraping off the tissue or eating holes in the leaves or flowers. Their slime trails may remain for days on rocks, sidewalks or the painted siding of houses.

Control

Insofar as practicable, eliminate hiding places and breeding areas. These often can be traced by following slime trails. Put out a few pieces of shingles or boards for traps. Collect and destroy trapped slugs and snails every day or two. Look for them under flower pots and under pot rims too. Collect slugs and snails from the plants at night.

If further control measures are needed, use a commercially prepared slug and snail bait containing mesurol or metaldehyde. Apply as directed on the label. Baits should be placed just after a rain or after garden watering as this is when slugs and snails are more active.

Insecticide label clearances are subject to change and changes may have occurred since this publication was printed. The pesticide USER is always responsible for the effects of pesticides on his own plants or household goods as well as problems caused by drift from his property to other properties or plants. Always read and follow carefully the instructions on the container label.