Potato, Irish-Slug

Grey field slug or grey garden slug (Deroceras reticulatum)

Pest description and crop damage This slug is native to northern Europe, North Africa, and the Atlantic Islands. It is present in the U.S. in several states and was first reported damaging potatoes in storage in 2017.

Biology and life history Little is known about the biology of the species related to potatoes in the field and in storage. They damage harvested potatoes by building thick galleries that are different than the ones described for wireworms or tuberworms. In general, the entry hole is round and slugs of different sizes can be found inside tubers. Galleries can be subsequently infested by flies or saprophytic beetles.

Scouting and threshold Slugs are not a common problem in potato production, thus, there are no established scouting methods and thresholds.

Management If there is a slug problem in a storage unit it is because slugs are coming from the field, thus, potatoes entering storage should be slug-free. The only report in the literature on infestation in storage is from the Netherlands where the pest was controlled with a sprout inhibitor. For more information see https://link.springer.com/article/10.1007/s12230-019-09728-5.

Management-chemical control: HOME USE

  • iron (ferric) phosphate bait-Slower activity than metaldehyde baits, and application rate is three to four times higher than that of metaldehyde. Some formulations are OMRI-listed for organic use.
  • metaldehyde bait-Broadcast to seedbed around borders and between rows. Do not apply directly to plants. Use this product with caution, as it is toxic to pets.
  • sodium ferric EDTA