Pensacola News Journal

For: Saturday, May 25, 2002

By: Daniel E. Mullins

Extension Horticulture Agent

Santa Rosa County

Mole Cricket Control Season Approaching

Mole crickets are among our most serious insect pests of lawns and gardens. They damage plants by tunneling in the soil, which exposes and dries out roots. They also feed upon roots and grass blades at night.

Evidence of their presence can be seen as tunneling or as small mounds of soil being pushed up between grass runners in the lawn. Bermuda and bahiagrass is most severely damaged, but injury to centipede, St. Augustine and Zoysiagrass is also common.

We have a native mole cricket species, but it is rarely a pest. It’s the exotic species that are responsible for most of the plant damage that is seen. These exotics include the tawny, southern and short-winged mole crickets. They were introduced into the United States in the early 1900s and, since they have few natural enemies, have expanded their range and reproduced virtually unchecked.

Mole crickets produce only one generation per year, so understanding their biology goes a long way toward the timing of control measures. They spend the winter as adults deep in the soil and emerge as the soil warms in the spring. Following some spring feeding, they fly, mate and begin laying eggs. Studies have shown that most egg laying occurs between early May and mid June.

Late June or early July is therefore considered to be the most ideal time to apply control measures. By then, most young crickets have hatched, are in an active stage and are most vulnerable to currently used control materials.

The mole crickets can be monitored to determine numbers present and if treatment is required. This can be done by using the soap flush method. Mix 2 tablespoonfuls of lemon scented dishwashing detergent in 2 gallons of water and apply with a sprinkling can to a 2 x 2 foot square area. Check several different areas within the lawn, and if an average of 2 or more mole crickets come to the soil surface within 3 minutes, control measures are justified.

The soap flush method works well when done properly. Prior to using it, make sure that the soil has been deeply moistened several hours ahead of time. If the soil is dry, the crickets will be too deep for contact by the solution. Check where grass is alive and avoid problem areas or dead spots. Remember that the mole crickets will be small at this time of the year, so watch closely after applying the solution.

There is a new biological agent and several chemical insecticides that can be recommended for control. A parasitic nematode, Steinernema scapterisci, infests mole crickets and they usually die within 12 days. This product was developed by University of Florida scientists to provide long-term biological control and is now patented.

The University of Florida has issued an exclusive license to produce the nematodes to the U.K. company, MicroBio, owned by Becker Underwood of Ames, Iowa. Microbio is selling the product to commercial or volume users under the name Nematac S. It is available in consumer sized packaging from Gardens Alive®, a mail order garden supply outlet (www.GardensAlive.com).

Chemical control products are available in liquid, granular and bait formulations. Baits are usually used in late summer when nymphs are larger. Currently recommended insecticides for the homeowner include products that contain the following active ingredients: bifenthrin, cyfluthrin, fipronil, imidacloprid or permethrin.

Always be sure to follow the manufacturer’s label recommendations. Most mole cricket control failures can be traced to improper timing or application methods. Contact your local Extension office or landscape maintenance professional for further information on recommended pesticides.