2010 Mole Cricket Control Project

published in The Florida Cattleman and Livestock Journal, May 2010
by Reyna Speckmann, UF/IFAS

What is this project?

The Southern Region Integrated Pest Management Center and UF/IFAS Extension Deans recently funded a demonstration project to educate Florida beef and forage producers about biological control methods for pest mole crickets in pastures. Dr. Howard Frank, Dr. Norm Leppla, Ed Jennings and Randy Bateman are the project directors working in close collaboration with county Livestock Agents. The goal of this project is to demonstrate the use of the mole cricket nematode product, Nematac S, which can be used in conjunction with the mole cricket wasp. The funding was provided to fabricate two nematode applicators, one to be housed in Ona, the other in Hastings, and to conduct demonstrations on how to use the equipment. These machines will be used to apply 15 billion nematodes to mole cricket infested pastures during regional field days in the spring and fall of 2010. If you believe your pastures are infested with mole crickets and you are interested in participating as a field day host, please contact your county livestock extension agent or one of the participating agents listed below.

What are mole crickets?

Pest mole crickets are large soil-dwelling insects that cause more than $100 million annually in damage to pastures in Florida. Mole crickets feed at night on above ground leaves and stems and below ground roots and tubers.

How do mole crickets damage pastures?
Tunneling activity dislodges plants, causing them to dry out. The combined feeding and tunneling damage to the plants first appears as yellow spots in the pasture, and eventually results in plant death and an ultimate reduction in available forage.

How do you detect a mole cricket problem?

Initial warning signs of mole cricket infestation include yellow or dead patches of grass and raised tunnels visible on the soil surface. To determine if your pasture damage is the result of mole crickets, a simple visual test can be performed. Start by combining one tablespoon of dish detergent per gallon of water in a bucket. Pour the solution in a 2’ x 2’ area where you suspect mole crickets are present. Because it is difficult for most of us to visualize a 2’ x 2’ area, a quadrant can be easily constructed from half inch PVC pipe and 90 degree elbows. The soap solution will cause any mole crickets inside the quadrant area to migrate to the soil surface. A mole cricket problem is indicated by the surfacing of four or more mole crickets within 3 minutes at multiple locations in your pasture.

How do nematodes control mole crickets?

Nematodes are microscopic worms that that have been used as a bio-pesticide for mole cricket control since the 1980’s. During the juvenile stage, nematodes infect mole crickets through the mouth and other openings, and migrate to the body cavity where specialized bacteria from the nematode digestive tract are released. The mole cricket is killed when these bacteria multiply. Nematodes complete their lifecycle and reproduce inside the host, increasing total nematode numbers in the soil available to infect other mole crickets. Most mole crickets are killed within seven to ten days of nematode application. The nematodes can move only a very short distance, so they rely on a host mole cricket to contact them in the soil. Once infected, mole crickets can fly as far as a mile before dying and releasing the nematodes to other parts of the pasture or ranch. Nematodes remain in a pasture indefinitely, generation after generation, as long as there are host mole crickets present.

When should nematodes be applied?

Nematodes applied in the soil will eventually die if they are not successful in finding and entering a host mole cricket. Applications are timed when chances of infecting mole crickets are highest, usually from late February through April and September through November, depending on weather. This year, a cold February and March will allow us to extend the application window into early May.

Who can provide additional information?

For additional information on mole cricket control in hayfields and pastures or participation in a field day, please contact your local county extension office.