…the slimy worm-looking things covering the sidewalks around campus this week. They are the immature form of craneflies, commonly known as leatherjackets.
I’m hoping it’s not too late to save our campus lawns, but by the time this kind of damage is apparent, insecticides may not be effective. By mid-May, the leatherjackets will pupate then hatch into adults. Adults are harmless (other than a nuisance).
Maintaining grass health is the best defense against craneflies. Monitoring should be done from January to March, when larvae are feeding underground. More information is available at: http://whatcom.wsu.edu/cranefly/Index.htm
NEW! OSU EXTENSION PUBLICATION (Sept. 2020): Managing Crane Fly in Lawns (EM9296)