Mole crickets are insects known for their burrowing habits. Belonging to the family Gryllotalpidae, they are related to grasshoppers and other crickets. Their specialized forelimbs are adapted for digging, allowing them to tunnel through soil. This activity can lead to issues in lawns and gardens.
Identifying a Mole Cricket
Mole crickets have a robust, cylindrical body, 1 to 1¾ inches long as adults. Their coloration varies from dark to golden brown. Their most distinguishing feature is large, shovel-like front legs, designed for efficient digging. Unlike other crickets, their hind legs are shorter and used more for pushing soil than for jumping.
Evidence of mole crickets often appears before the insects are seen. Common signs include raised tunnels or ridges in the soil, resembling miniature molehills. Lawns may also feel spongy due to turf detachment from their burrowing. Patches of brown or dying grass can indicate their presence, as their activity disrupts plant roots. To confirm, pour a mixture of dish soap and water over a suspected area; they will surface within minutes.
Life and Behavior
Mole crickets are primarily nocturnal, spending most of their lives underground in burrows about ½ inch in diameter. They are found globally, inhabiting moist, loose soil, with a preference for sandy soil. Their diet varies by species; some are herbivores, feeding on roots and plant matter, while others are omnivores. Southern mole crickets, for instance, are primarily carnivorous.
The mole cricket life cycle involves three stages: egg, nymph, and adult. Mating occurs in spring, often in April and May, with males attracting females through courtship songs amplified by specially constructed burrows. Females lay clutches of 25 to 60 eggs in underground chambers, hatching after 10 to 40 days. Nymphs resemble smaller adults without fully developed wings and undergo several molts before maturity. Mole crickets are active most of the year, overwintering as nymphs or adults in cooler climates.
Garden Impact and Control
Mole crickets can cause damage to lawns, gardens, and turfgrass, particularly in southern regions. Their tunneling disrupts soil structure, severing grass roots and stressing plants, which can lead to death. This often results in irregular, brown patches of dead grass. Beyond tunneling, some species feed directly on plant roots, shoots, and young seedlings, causing further plant decline. Crops like potatoes, radishes, and various vegetables are also susceptible.
Controlling mole cricket populations involves an integrated pest management (IPM) approach combining cultural, biological, and chemical methods. Cultural controls include maintaining a healthy lawn with proper irrigation and selecting less attractive grass species; reducing outdoor lighting can also decrease their attraction. Biological options include beneficial nematodes like Steinernema scapterisci and parasitic wasps like Larra bicolor, which provide long-term management. Chemical controls, in granular or liquid form, are applied to the soil, often when nymphs are young in early summer. Products with bifenthrin, carbaryl, or imidacloprid are common; applying treatments to moist soil improves effectiveness by encouraging mole crickets closer to the surface.