**Mole Crickets** (family Gryllotalpidae) are large, cylindrical insects easily recognizable by their extremely large, heavily muscled forelegs, which are modified into shovel-like structures adapted for burrowing through soil. They are significant agricultural and turfgrass pests because their tunneling physically disrupts plant root systems, and some species also feed directly on roots, tubers, and turfgrass crowns. They cause widespread damage, especially in sandy, well-irrigated soils.
Taxonomy and Classification
Mole Crickets belong to the order Orthoptera (grasshoppers and crickets). They undergo incomplete metamorphosis. They are highly subterranean, spending most of their life underground, emerging primarily at night or during the mating season, when the males produce a characteristic, low-frequency song to attract females.
Physical Description
Adult Mole Crickets are stout, brown, and velvety, 1 to 2 inches long.
- **Appearance (Key ID):** Large, mole-like, shovel-shaped forelegs. They have two short, thread-like antennae and two long cerci (tail filaments) at the posterior end.
- **Habitat:** Sandy or loose soil, especially in well-watered turf, golf courses, and vegetable gardens.
- **Damage Sign (Key ID):**
- **Tunnels:** Raised, squiggly soil tunnels or ridges visible across the turf surface, similar to mole damage but smaller.
- **Dead Patches:** Irregular patches of grass die (especially due to feeding on the crown and roots).
- **Excavation:** Young seedlings or tubers are chewed or physically pushed out of the ground.
- **Conflict:** Significant turf and crop damage.
Distribution and Habitat
Mole Crickets are found globally, with specific pest species being highly problematic in the southern U.S. (e.g., Tawny and Southern Mole Crickets). Their preferred habitat is soil that is loose enough for easy tunneling, often making them severe pests in high-value turf and vegetable crops.
Behavior and Conflict
The conflict is a combination of physical and feeding damage.
- **Physical Damage:** The primary tunnels disturb the root-soil interface, causing young plants to dry out and die (especially seedlings).
- **Direct Feeding:** Herbivorous species feed directly on roots and crowns, causing extensive turf loss.
- **Nocturnal Activity:** Their subterranean and nocturnal habits make them difficult to detect and treat effectively.
Management and Prevention
Control is integrated pest management (IPM), with a heavy focus on timing and chemical control.
- **Flushing:** Use a soapy water solution poured over suspected areas. The irritation forces the crickets to emerge, allowing for population estimation.
- Use parasitic nematodes (*Steinernema scapterisci*) or parasitic wasps (*Larra* species), which are highly effective against specific pest species of mole crickets.
- Apply a registered insecticide (granule or liquid) when the nymphs are small (late spring/early summer), as this stage is the most vulnerable and causes the most damage later in the season.
- Treatments are most effective when applied in the late afternoon and watered in lightly.
Conservation and Research
Mole Crickets are managed as high-priority turfgrass and agricultural pests. Research focuses on optimizing the field release of biological controls (especially nematodes) and developing predictive models for population outbreaks based on soil and weather conditions.