Mole Cricket Management

There are several species of Mole Crickets in North America, of these only three species are considered to be major pests. Those species are the Tawny Mole Cricket, Scapteriscus vicinus, Southern Mole Cricket, S. borellii and Shortwinged Mole Cricket, S. abbreviatus).

Range

Mole Crickets are usually considered a turf grass pest, Scapteriscus spp. mole crickets have a broad diet. The Southern Mole Cricket feeds mainly on other insects, and the Tawny and Shortwinged Mole Crickets feed on plants. Commonly injured plants include tomato, strawberry, beet, cabbage, cantaloupe, carrot, cauliflower, collard, eggplant, kale, lettuce, onion, pepper, potato, spinach, sweet potato, turnip, chufa, peanut, sugar cane, tobacco, such flowers as coleus, chrysanthemum, and gypsophila, as well as weeds such as pigweed. The Tawny Mole Cricket often injures bahiagrass and bermudagrass, and the shortwinged mole cricket often attacks St. Augustinegrass and bermudagrass.

• Tawny Mole Cricket is a major pest of vegetable seedlings, turf and pasture grasses. Tawny Mole Crickets feed largely on plant material, and only to a slight extent on insects and other animals.
• Southern Mole Cricket includes ants in their diet, and they may perhaps feed on fire ants among other ants. The southern mole cricket damages turf and pasture grasses, mainly by tunneling (because it is largely carnivorous). Perhaps plant feeding occurs when animal material is in short supply. Relatively very little damage is caused to plants by Southern Mole Crickets as a consequence of this diet.
• Shortwinged Mole Cricket is a pest of vegetable seedlings and turf. The Shortwinged Mole Cricket feeds largely on plant material, and only to a slight extent on insects and other animals. They feed on plant roots, stems, and leaves in much the same way as does the Tawny Mole Cricket. Where they are the dominant species, for example in coastal areas of southeastern Florida, they are the major pest among the mole crickets.

1. In the continental USA, almost all populations are very close to the coasts of eastern Florida and southwestern Florida
2. The AZ-CA distribution is in the vicinity of Yuma
3. In the continental USA, almost all populations are in light soils in the coastal plains

Damage

Mole crickets usually damage plants by feeding at night. They will feed on the above ground foliage or stem tissue and belowground on roots and tubers. Many seedlings may be girdled at the stems near the surface of the soil while some small plants may be completely severed and pulled into a tunnel to be eaten. When you have Mole crickets tunneling near the surface of the soil this will uproot or dislodge plants. This causes them to dry out. Small mounds of soil and the tunneling that the Mole Crickets leave behind during their hunt for food will reduce the aesthetic quality of your turf grass lawn or golf course. While the tunnels, will also interfere with the roll of the ball on the golf courses, which can result in a loss of revenue to the golf course. Severely infested pastures can result in reduced livestock grazing which can mean increased cost to the farmer.

Life Cycle

The Southern and Tawny Mole Crickets are very similar in appearance and biology, while the Shortwinged Mole Cricket shorter wings which prevents flight, and males have no calling song. The eggs of these three species are laid in April-May, and nymphs occur through August. However, in southern Florida, the Shortwinged Mole Cricket can produce eggs throughout the year. Some adults will occur in August or September, but both nymphs and adults overwinter. Overwintering nymphs will become adults by April, and adults fly and mate. One generation per year is normal, though in southern Florida southern mole crickets have two generations and fly three times (spring, summer, and autumn). Due to temperature differences, adult southern and tawny mole crickets emerge earlier in the year in southern Florida than in northern Florida.

Description

• Eggs: About 25-60 eggs per clutch are laid in a chamber in the soil. The chamber can be 5-30 cm below the soil surface, and measures 3-4 cm in length, width, and height. Egg development lasts about 3 weeks, depending on soil temperature. Females may lay up to 5 clutches of eggs before dying.
• Nymphs: Nymphs hatch from eggs from April to June. Nymphs resemble the adults, but their wings (wing pads) are not completely developed. The number of instars is variable, probably 8-10.
• Adults: Mole crickets have enlarged forelegs that they use to dig in soil. The forelegs have large blade-like projections, called dactyls, and the number and arrangement of dactyls, and the pronotum pattern are used to identify different species.

Keys To Identifying Mole Crickets

Tawny and Southern Mole Cricket males attract females by producing a courtship song from their burrows early in the night. Mating and dispersal flights occur in spring, from late February to April.
Tawny Mole Crickets look similar to Southern Mole Crickets, with moderately long forewings and long hind wings, a yellowish brown body, and a dark pronotum with a central band. Dactyl spacing distinguishes between the two species. The dactyls nearly touch at the base, like the shape of a "V". The Tawny Mole Cricket's calling song occurs during the first 90 minutes after sunset.

Southern Mole Crickets have long hind wings that extend past the abdomen and are rounded at the tips. Adults are brownish-gray with a dark pronotum. The dactyl spacing is similar for shortwinged mole crickets (looks like a "U"), so these two species can best be distinguished by wing length. The Southern Mole Cricket's calling song occurs during the first two hours after sunset. As a predator, the Southern Mole Cricket is more active and tunnels more than the Tawny Mole Cricket.
Shortwinged Mole Cricket adults are 22 to 29 mm long, with wings shorter than the pronotum (area behind the head). The body is mostly tan in color, but the pronotum is brown mottled with darker spots. The top of the abdomen has a central row of large spots, and smaller spots to either side. Dactyl spacing looks like a "U". Shortwinged Mole Cricket males have no calling song.

Management

Several methods are used to estimate mole cricket populations and assist in timing pesticide applications. One way is to rate the amount of tunneling damage that is visible. Tunneling is most obvious in low-cut grass or areas with minimal vegetation, and thus can be detected easily in crops, bahiagrass lawns and pastures, or Bermuda grass fairways. The tunnels are most visible in early morning, when the dew is on the grass and the soil may be moist.
A more consistent but labor intensive method of sampling is a "soap flush." Flushing is more effective in moist soil. Mix 1.5 oz (2 TBSP) of lemon liquid dishwashing soap in 2 gal of water in a sprinkling can, and pour the solution onto 3-4 sq. ft. of turf. If two to four mole crickets emerge within 3 minutes after applying the soap solution, insecticide use may be justified. Flushing with a synergized pyrethrin insecticide solution is equally effective.

Insecticides

Liquid and granular formulations of pesticides are commonly applied to the soil to suppress newly hatched mole cricket nymphs from April to June. Irrigating before an insecticide application may drive mole crickets closer to the soil surface, and helps the pesticide to penetrate into the soil. Some insecticides should be watered in after application to move them into the root zone of the plants where the mole crickets are feeding. However, it is essential to read and understand the insecticide label carefully for application directions.
Bait formulations are useful against larger nymphs in late summer. Mole crickets feed at night, so baits should be applied in the early evening. Baits should not be used when you use irrigation or have any rain in the near forecast.

Recommended Products for Mole Cricket Control

Maxforce Insect Granules
Talstar P
Talstar PL