Bug of the Month Sept. 2020
Bug of September is not a bug!
By Héctor Cárcamo
Slugs are a common nuisance in most people’s gardens, especially in wet spots and wet summers. In fact, they can also be a pest in farmers’ fields. In central Alberta, around the Lacombe – Ponoka region (and elsewhere) slugs have been observed at high densities that cause noticeable damage in canola and cereal crops. In wheat, their damage is almost indistinguishable to that of cereal leaf beetle, which coincidentally has a sluggish appearance due to their “nasty” habit of covering themselves in their own poop constantly.
The best way to confirm that you have slugs in your field is to make a night visit when they are actually feeding. Managing slugs is a major challenge because the standard insecticides do not work against them. Managing a slug infestation is very difficult; consult this site for some ideas such as management of heavy crop residue.
One important thing to remember is not to confuse slug damage with cereal leaf beetle, which is usually managed well enough by its own parasitoid wasp, T. julis. Dr. Lien Luong at the University of Alberta (email@example.com) studies slug biology and management and may still be interested in samples.