Crop Damage and Symptoms

ragged holes                            


Slug damage is grouped into the following categories and are pictured above:

  • Scrape, shred, make ragged holes

  • Kills apical meristem and destroys growing points

  • Hollow out seeds

  • Scar roots and tubers


Damage to young seedlings is apparent when partial or entire rows disappear during the early weeks after planting. Young sprouts and tender leaves are shredded, resulting in plant death or retarded growth.

Slugs eat foliage with rasping-grating ‘teeth’ mouthparts, and you can find them shredding, stripping, scrapping, and feeding between the leaf veins. The plant skeleton will dry out and disappear rapidly. Search at night for their presence to make sure you are not confusing slug damage with another organism.

Silvery, “slime” trails are left behind on leaves and soil not produced by other common pests. Nightcrawlers are the only other producer of slime, however the slime looks different, and they do not directly damage plants, other than pulling seedlings into their burrow.

Holes can be seen from slug damage to underground plant parts and germinating seeds, cotyledons, and the first little leaves of fall or spring-planted crops. Damage to underground parts of plants from roots and tubers is characterized by shallow to deep smooth-sided pits.

Slugs can defoliate the growing tip and reduce the plant stand, particularly when moist soil conditions prevent the seed slot from closing completely.

Damage to second or third year established plants is sometimes less apparent unless early spring season or winter leaf damage occurs.

Slug damage to reproductive and vegetative tillers occur, however symptoms are not necessarily recognized and therefore goes undetected.

The biggest plant losses are reported on spring and fall-planted establishing seedlings. Adult slugs are most responsible for the damage to fall-planted crops.