In addition to earthworms, there are several insects that can create small mounds of soil above the surface of turfgrass. Occasionally, the mounds can become a nuisance, especially on closely mowed greens where they are more noticeable and may interfere with play.
The photos below depict one such insect, the seed corn beetle, and the kind of damage it can cause on putting greens. Superintendents across northern Indiana are currently noticing a fair amount of this activity.
Despite their name, corn seeds are not the primary food source for seed corn beetles. Rather, they feed on other things they find in the soil including other insects. They are also highly attracted to lights at night. There are two generations per year, typically occurring in May/June and again in August.Although these beetles are generally beneficial and do not represent a serious management concern, their damage can sometimes be an annoyance. Management recommendations for these beetles usually include applying a surface insecticide (e.g. pyrethroid) as soon as mounds appear. Superintendents who have in place preventive white grub/cutworm applications using a higher rate of Acelepryn (16 floz/Acre) have reported success at minimizing damage and witnessed dead beetles to serve as evidence.
Figure 2. Damage to a golf course green caused by burrowing activity of adult seed corn beetle
Doug RichmondPurdue University Turfgrass Entomologists