Issue 17, September 28, 2009
Mole Crickets
Mole crickets are occasionally reported as being associated with turf damage in Illinois. These are the northern mole cricket, Neocurtilla hexadactyla. Our climate is too cold for the subtropical tawny mole cricket or others in the genus Scapteriscus that are serious turf pests from the Carolinas to eastern Texas on south.
The northern mole cricket, which is native to Illinois, feeds on plant material in high moisture situations. They appear to be primarily scavengers, feeding on grass and other plant material that is dying or rotting. I have collected them several times in the mud and debris under water at the edge of ponds and streams. They are considered to be a semi-aquatic insect.
Adult northern mole crickets are medium to dark brown, elongate, somewhat cylindrical, and about one and one-quarter inch long. They have the enlarged hind legs associated with jumping in other crickets, but their most obvious characters are widened, spade-like tarsi at the end of the front legs. These crickets use their mole-like front legs to dig through the soil. Much of their tunneling is near the soil surface, resulting in winding, mole-like tunnels that are one-fourth to one-half inch high and wide. Adults have wings, allowing them to leave their burrows to fly at night. They are attracted to lights at night, which is where the average person is likely to see them.
They have one year life cycles. Males construct an enlarged amplification chamber at their burrow openings. They then sit in these chambers and sing to attract females to them for mating. Different species of mole crickets can be distinguished readily by their song.
I have had golf course superintendents and others contact me a few times over the years about damage to turf by northern mole crickets. In each case, it has been turf growing at the edge of water hazards or ponds where the roots were trying to grow in water-saturated soil, and the turf was barely alive as a result. It was hard to tell whether the mole crickets were feeding on live grass or dying grass.
Mole crickets are controlled with the same insecticides as those used for white grubs, but if they are feeding on turfgrass that is already in decline due to high soil moisture levels, treatment should not be warranted. If you have situations where mole crickets are damaging turf that is not water-saturated, I would welcome the chance to visit the site.--Phil Nixon
Author:
Phil Nixon