Issue 17, October 19, 2016
Seed Corn Beetle
Seed corn beetles, Stenolophus lecontei, have been a problem in turf this summer, particularly on golf course greens. Seed corn beetles are about one-quarter inch long and brown to reddish-brown with black heads and two wide black stripes on the wing covers. They have long antennae.
Seedcorn beetle adult.
These are ground beetles in the Family Carabidae. Ground beetles are predatory with both the larvae and adults feeding on insects and snails in the soil. Only adults are being found, apparently being attracted to lights or moisture. They tunnel into the soil, producing small, one-fourth to one inch, mounds of soil similar in appearance to castings made by earthworms. They do not appear to causing direct damage to the turf.
Many contact insecticides are effective against them including azadirachtin (Azatin), carbaryl (Sevin), and trichlorfon (Dylox). However, more beetles will fly onto the course and are likely to not be controlled with the previous insecticide application. Azadirachtin has repellent properties, and there have been reports of longer lasting control with that insecticide. (Phil Nixon)