Mole crickets cause damage by tunneling through the soil and feeding on the roots, stems and blades of grass. They push the dirt up and your lawn seems spongy when you walk on it.
At this time of year, though, most of the crickets in your lawn are babies. The small crickets spend more time at or near the surface and are relatively easy to kill with insecticides.
If you suspect mole crickets have infested your lawn, take some soapy water (dishwashing detergent is fine) and pour it on the lawn just before sunset. Soap will irritate them and make them come to the surface .
Mole crickets spend the winter deep in the soil, predominately as adults and large nymphs (immature stage). Sometimes, in abnormally warm spells, they will come to the surface to feed. Those that over-winter as nymphs complete development and become adults in the spring, just in time for mating season. Mating takes place in late winter and early spring as the soil and air temperatures warm.
Males and females fly on warm, humid nights from early April to early June, sometimes in large numbers, looking for mates or areas to lay eggs.
Approximately 14 days after mating, the female lays 35 to 40 eggs in the soil. The adults die after mating so there are few left after June. The eggs hatch around the fourth of July.
Early nymphs may live in an area of only a few square feet and cause little noticeable damage. In fact, it is not uncommon to find 5 to 10 nymphs per square foot with little or no turf injury.
As they grow , they may tunnel over several yards and cause extensive damage to the lawn.
If control measures are not taken by late summer and early fall, the mole crickets are big again and much harder to kill.
The insecticides to control mole crickets include fipronil, bifenthrin, and imidacloprid.
Fipronil (sold as Top Choice) is the most effective and gives year-long control but it is packaged more for commercial operators. It comes in a 50-pound bag that costs about $125.
Bifenthrin is packaged more for homeowners and is sold as a granular or liquid. Talstar and Ortho Max Bug-B-Gon are a couple of brand names.
Imidacloprid is generally sold as Bayer Advanced Lawn - Season Long Grub Control or Complete Insect Killer.
Mole crickets are sensitive to soil moisture and will move down in the ground to find comfortable conditions if the surface is dry. Watering will bring them back up to resume feeding the following night, thus making them easier targets for control.
First, allow the soil to dry for three to four days and then irrigate thoroughly the following evening. Mole crickets feed at night, so apply the insecticide the next evening, just before dusk.
If using a liquid, apply at least one gallon of solution per 1,000 square feet. Unless the label instructs otherwise, irrigate thoroughly after the application to move the insecticide off the foliage and down to the soil surface.
Sid Mullis is the director of the University of Georgia Extension Service Office for Richmond County. Call him at (706) 821-2349, or send e-mail to firstname.lastname@example.org.