Common Name: Mole cricket
Scientific Name: Scapteriscus borellia Giglio-Tos
Description: Mole crickets have front legs enlarged, shovel-like and modified for digging. Adults are cylindrical, nearly 1-1/2 inches long and dull brown. The shield-like segment just behind the head (pronotum) is marked with two pairs of pale spots. There are two finger-like projections (dactyls) on the terminal segment of the front leg (tibiae) separated by a u-shaped gap, and the hind tibiae is longer than the pronotum. Adults have well-developed wings covering 3/4 of the abdomen when held at rest. They fly at night, can run quickly, but are poor jumpers. Nymphs resemble adults but are smaller and do not have fully developed wings.
The northern mole cricket, Neocurtilla hexadactyla (Perty), is a native species and also occurs throughout the eastern part of Texas. Although less numerous, it produces damage similar to the southern mole cricket. It can be identified by having four fingers on the dactyls on the digging claw. The tawny mole cricket, Scapteriscus vicinus Scudder, is closely-related to the southern mole cricket. It occurs in other southeastern states as far west as Louisiana, and has only recently been detected in Texas. This is a plant feeding (phytophagous) species that tends to occur in much higher numbers and causes more extensive injury to turfgrass and crops. In contrast to the southern mole cricket, the tawny mole cricket lacks pale spots on the pronotum and the space between the pair of dactyls on the front tibiae is smaller, appearing V-shaped.
Life Cycle: Simple metamorphosis (egg, nymph, adult). Winter is spent as partially grown nymphs and as adults. In spring and early summer, mating and dispersal flights occur and afterwards females lay eggs in cells dug in the soil. Eggs hatch in about 2 weeks and nymphs develop through eight stages (instars) during the summer months. One generation is produced per year, although a second generation may occur in southern Texas.
Habitat, Food Source(s), Damage: This is a soil insect (feed at or slightly below the soil surface on roots, tubers and stems) that invades soil in pastures, gardens, field crops and turfgrass. Infestations are usually very spotty and localized. Mole crickets prefer sandy soil and are often found in golf courses and live in 1/2 inch diameter burrows. They are active at night and either tunnel just beneath the surface up to 20 feet per night when soil is moist in search of insect prey or come to the surface and run about freely.
Tunneling activities can be very disruptive to many plants. They loosen the soil around the root system, causing the roots to dry out. Bermudagrass and bahiagrass, particularly in areas with sandy soil, are often more affected than St. Augustinegrass. Reduction of plant stand is common. The small mounds and tunnels or ridges of soil are a particular problem on golf course putting greens.
Pest Status: Feeds primarily on other insects and earthworms as nymphs and adults; their prey-searching activities involving digging shallow tunnels in soil, resembling mole runs, which disrupt rootsystems of turfgrass and crops. The southern mole cricket occurs in the eastern one-third of the state, having spread westward after being accidentally introduced into Galveston and other southeastern locations form South America around 1900. Life stages are not medically harmful to man and animals.
Literature: Brandenburg and Villani 1995; Brook et al. 1982; Crocker and Beard 1982; Niemczyk 1981; Sailer et al. 1984.