Conifer and Hardwood Insects 47. Mole Crickets Coleman Doggett Hosts Diagnosis become adults, develop wings, fly to new locales, and construct tunnels. Adults are Mole crickets are in the family Gryllotal­ Adult mole crickets are 2.6 to 5.2 cm (1.0 strong fliers and may fly up to 5 miles. pidae. The forelegs of these insects are to 2.0 in) long with large shiny black eyes Inside the tunnels, the males produce modified for digging. Three introduced and range in color from yellowish brown mating songs or rasps to attract mates. species—shortwinged mole cricket, to dark brown (fig 47.1). Their front legs After mating, the female digs a nursery Scapteriscus abbreviatus; southern mole are stout and shovel­shaped with claws chamber and lays her eggs to begin a new cricket, S. borellii; and tawny mole for digging. They tunnel underground and generation. Mole crickets are nocturnal cricket, S. vicinus—are very destructive spend most of their lives in their tunnels. and are seldom seen in daylight. to seedlings, while the several native U.S. The tunnels are around 3 mm in diameter species seldom cause damage. A wide and may be visible on the soil surface. Mole crickets have many natural enemies. variety of both hardwood and softwood Occasional small soil mounds on the Predators include birds, toads, shrews, species are killed by mole crickets, ground surface above the tunnels indicate moles, rats, skunks, raccoons, foxes, and either by feeding or by the indirect effect where the insects have surfaced. armadillos. of their tunneling. Seedlings attacked include the southern yellow pine, eastern Biology Control redcedar, elm, maple, sweetgum, and yellow­poplar. Adult mole crickets lay 25 to 60 eggs in Biological an underground chamber in April or May. Distribution One species, the shortwinged mole crick­ A parasitic wasp, Larra bicolor, was et, however, can produce eggs all year. introduced from South America to control The introduced species are currently The eggs hatch into nymphs in 3 to 4 mole crickets. It is established in Florida found from Texas to New Jersey. weeks and the nymphs begin to build un­ and appears to be surviving and spread­ derground tunnels and feed. Nymphs are ing. A parasitic fly,Ormia deplete, also Damage similar to adults except that their wings from South America, has been introduced. are not developed. They feed on plant In addition, a nematode, Steinemema Mole crickets feed on seedling roots roots and stems, earthworms, and other scapterisci, has been introduced and and lower stems. Belowground damage insects. There are one or two generations has been effective for control. It is com­ initially results in wilting and if damage per year, with two generations occurring mercially available and has proven to be is severe, eventual seedling death. The in the southern part of their range. After persistent for up to 8 years. winding tunnels constructed by the feeding for several months, the nymphs insects cause topsoil disturbance, which may result in mortality to very small seedlings when rain splash covers them with soil. Seedlings may also be severed or girdled just above the groundline. When affected seedlings are examined, major and or minor roots may be missing due to insect feeding. Figure 47.1—Mole cricket. Photo by Richard Grantham, Oklahoma State University. Forest Nursery Pests 153 Conifer and Hardwood Insects 47. Mole Crickets Chemical the insects closer to the surface. Some Selected References insecticides require post application irri­ A number of both general and restricted­ gation to carry the insecticide to the mole Anon. 1983. Insects of conifer roots: mole crickets. Bull. No. 196­A. Tallahassee, FL: use pesticides are currently registered for crickets. These requirements are included Florida Division of Forestry. 1 p. mole cricket control. These chemicals on the product label. include both liquid and granular formula­ Arnold, D.; Rebeck, E.; Royer, T.; Mulder, tions, as well as baits. Chemical control Most available baits contain a grain­based P.; Kard, B. 2008. Major horticultural and is most effective when nymphs are small, attractant plus an insecticide. Since mole household insects of Oklahoma. E­918. Okla­ late June and early July in the mid­South. crickets are nocturnal, baits should be homa City: Oklahoma Cooperative Extension Chemical control becomes less effective applied in the evening. The effectiveness Service. 176 p. as the insects age. of the baits that are currently available is Buss, E.A.; Capinera, J.L.; Leppla, N.C. 2006. decreased if rainfall or irrigation occurs Pest mole cricket management. Extension Irrigation before insecticidal application before the insects feed on the bait. Publication ENY­324. Gainesville, FL: may increase effectiveness by driving University of Florida, Institute of Food and Agriculture Sciences. 6 p. USDA Forest Service. 1985. Insects of eastern forests. Misc. Pub. 1426. Washington, DC: USDA Forest Service. 608 p. 154 Forest Nursery Pests.