Thursday, August 5, 2010

Mole Cricket Hunters

Mole cricket, photo courtesy of Texas A&M Univ.

Summer is in full swing! It’s hot, rainy, and plants are growing. All of that tasty succulent growth is like a buffet for a wide array of lawn and garden pests. In the coming weeks you may discover that your lawn has mole crickets. Mole crickets are especially troublesome in bahiagrass lawns, but will damage other types of turfgrass. There are three species of mole crickets found in Florida: the shortwinged mole cricket, Scapteriscus abbreviatus; the southern mole cricket, Scapteriscus borellii; and the tawny mole cricket, Scapteriscus vicinus. Mole crickets are adept at digging and as they tunnel through the ground they sever grass roots. They eat both the roots and shoots of grass and will leave unsightly brown patches in your lawn and sometimes cause the earth to bulge up. To add insult to injury (literally) they are considered a tasty treat by raccoons and armadillos that may dig up your lawn for a mole cricket snack.

Mole cricket damage

There is an easy way to find out if you have these little diggers. Simply mix up a concoction of 1.5 ounces of liquid dishwashing soap in 2 gallons of water. Sprinkle this mixture over 4 square feet if your turf. If 2-4 mole crickets appear within three minutes of the application then you may consider a control program. There are several controls listed in the link below called “Pest Mole Cricket Management”, but I would like to focus on a particularly interesting method using “Mole Cricket Hunters” aka the Larra wasp, as a biocontrol.

Biocontrol is quite simply the use of a beneficial insect to control a pest insect. In the case of mole crickets there is a parasitic wasp called the Larra wasp (Larra bicolor) that will attack all three species of mole cricket here in Florida. (To learn more about the way they attack and kill mole crickets please see the last link below.) The Larra wasps do not sting humans unless you try to catch one and hold it in your hand. But why would anyone do a silly thing like that? They are already present in at least 31 Florida counties, including ours, so all you have to do is encourage them to frequent your landscape. How can you do that? It’s easy: plant host plants that the wasps obtain nectar from. The two most popular choices are shrubby false buttonweed (Spermacoce verticillata) and partridge pea (Chamaecrista fasciculata). They are both Florida native wildflowers and require very little assistance to grow and thrive. The University of Florida’s entomology department recommends planting these before you have a mole cricket problem, but there’s no time like the present to employ an environmentally friendly control like this! For more information please see the following links:

Mole Crickets

Pest Mole Cricket Management

Mole Cricket Hunters

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