Damage - This slug leaves a trail of slime wherever it goes. It eats large ragged holes in the leaves of mature plants and may completely devour small seedlings. They usually are most serious on plants growing close to the soil surface. Eggs are usually deposited under objects on the ground such as stones and boards. Immature slugs remain together in a colony near where the eggs are deposited for four to five weeks.
Activity is greatest during the night and on damp, cloudy days.
They can survive 30 to 34 C for a short while, but they immediately seek shelter to conserve moisture. They often feed and hide among the leaves of large-leafed plants. Outdoors they are among the first pests to begin feeding in the spring and among the last to stop feeding in the fall. Indoors they will feed as long as environmental conditions are favorable. In damp soil they tend to be solitary, but in dry soil spotted garden slugs bunch together.