Tawny mole cricket

What is tawny mole cricket?

The tawny mole cricket is one of three South American mole crickets that reached the southeastern U.S. around 1900. It was first seen in Brunswick, Georgia, in 1899, and it now ranges from North Carolina to Louisiana. Unlike the southern mole cricket, which mostly eats other insects, the tawny mole cricket feeds almost entirely on grass roots and shoots, which makes it the most destructive of the group on turf.

Mole crickets spend their lives in the soil, digging tunnels just below the surface at night as they forage, then going deeper when it is cold or dry. The tunneling loosens turf and dries out roots, and feeding thins the grass. Seedlings in gardens and new plantings can be cut off or uprooted. NC State reports mole crickets became the number one insect pest of home lawns, golf courses and sod farms along the North Carolina coast.

Timing is everything with this pest. NC State says waiting until serious damage shows means the season is already lost, so plan ahead and target small nymphs in early summer. Florida has also had real success with imported natural enemies: a wasp, a fly and a mole cricket nematode.

Signs and damage

• Raised, winding tunnels just under the turf surface.
• Thin, loose turf where roots and shoots have been eaten and the soil has been churned.
• Seedlings cut off at the soil line, pulled underground, or knocked loose and dried out by tunneling.
• Loud trilling calls from the lawn in the first hour or so after sunset.

Tawny mole cricket identification: what to look for

• Adult: Yellowish-brown with a darker pronotum (shield behind the head). Enlarged front legs with blade-like dactyls that nearly touch at the base, separated by less than half the width of one dactyl. Forewings and hindwings moderately long.
• Larva: Nymphs hatch whitish, darken within a day, and look like small wingless adults. They molt many times over several weeks, developing wing buds before the final molt.
• Eggs: Oval, gray to brownish, about 3 mm, laid in clutches of about 25 to 60 in a golf-ball-sized chamber 2 to 12 inches underground. They hatch in about 10 to 40 days.
• Damage: Surface tunnels, loosened and dried-out turf, root and shoot feeding, seedlings severed or uprooted.
• Timing: One generation a year. Eggs in spring (April to May in Florida, later farther north), nymphs through summer, adults from late summer. Both nymphs and adults overwinter.

Life cycle

Tawny mole crickets have one generation a year. Overwintered nymphs mature in spring, and females lay eggs in underground chambers around April and May in Florida (UF gives a general example of egg laying in April and May in Florida and May and June in North Carolina). Eggs hatch in about three weeks, longer in cool soil. Nymphs tunnel in the top 8 to 10 inches of soil and feed at the surface in the evening, growing through summer. New adults appear from about August or September, and both nymphs and adults spend the winter in the soil. Adults fly at night, mostly early in the evening (UF/IFAS).

When to look: In southern turf, plan in late spring and check for small nymphs in early summer, when NC State says young crickets are easiest to target. Watch for tunneling through summer and fall.

Tawny mole cricket look-alikes

A few things get mixed up with it:

• Southern mole cricket (Neoscapteriscus borellii): Brown, often with a dark shield; its front-leg dactyls are spaced farther apart, its wings are longer, and its song is lower and slower. It mostly eats other insects but does more tunneling.
• Shortwinged mole cricket (Neoscapteriscus abbreviatus): Whitish or tan with spots on the back and very short wings; it cannot fly and favors St. Augustinegrass and bermudagrass.
• Northern mole cricket (Neocurtilla hexadactyla): A native mole cricket that UF/IFAS says is not a pest and NC State calls less damaging.

How to control tawny mole cricket

Cultural control

• Plan ahead: NC State stresses preinfestation planning, because by the time damage is serious it is too late for that year.
• Where fine texture is not important, coarser bermudagrass cultivars are less susceptible than finer hybrids (NC State).
• Sample with a soap flush: UF/IFAS gives a dish-soap-and-water mix poured over 4 square feet, and says 2 to 4 crickets coming up within three minutes justifies control. Counting tunnels is common but less reliable.

Biological control

• Larra bicolor, a wasp imported from Bolivia in 1981, attacks mole crickets; it needs flower nectar, and planting the wildflower Spermacoce helps it survive (UF/IFAS).
• Steinernema scapterisci, a nematode introduced from Uruguay in 1985, kills infected crickets within about 12 days and works better on adults than nymphs (UF/IFAS). NC State notes nematode sprays can go through conventional equipment.
• Ormia depleta, a fly from Brazil released in 1988, is drawn to the males' calls and reduced injury in southern Florida (UF/IFAS).
• UF credits these three enemies with a decline in mole crickets in Florida, though damage still occurs under some conditions.

Chemical control

Target small nymphs soon after egg hatch. NC State says imidacloprid should go on while crickets are under 1/2 inch long, which it puts at June or early July, and lists indoxacarb (two applications 2 to 4 weeks apart after egg hatch) and dinotefuran (at egg hatch), along with bifenthrin, lambda-cyhalothrin and other active ingredients. UF/IFAS notes some soil treatments need irrigation to reach the root zone, while baits go out in early evening and are spoiled by rain or irrigation. Use only products labeled for this use; the label is the law.

Use only products labeled for this pest and this site; the label is the law. For trees, work with an ISA Certified Arborist. If you hire someone to apply pesticides, make sure they hold your state’s pesticide applicator license; the rules for each state are in our pesticide applicator license guide.

Prevention

• Use soap flushes in late spring and early summer to find young nymphs before damage builds.
• Support the imported natural enemies where they are established, including nectar plants for the Larra wasp.

When to call a pro

In southern lawns, golf courses and sod farms, work with a licensed pesticide applicator (see our pesticide applicator license guide) on an early-summer plan if soap flushes show mole crickets above the threshold.

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Questions about tawny mole cricket

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