Mole crickets
Stout burrowing insects with large digging front legs that tunnel through soil, cut roots and uproot seedlings in warm regions.
Also known as: Soil crickets
Symptoms and identification
Raised tunnels like thin ridges run across lawns and seedbeds. Seedlings wilt and fall over, roots and tubers are chewed, and patches of lawn turn brown and spongy. Light brown insects 3 to 5 cm long with shovel-like front legs are found when the soil is dug.
Causes
Mole crickets live in the soil, feed on roots and insects and are most active at night, especially after rain or watering. They are common in warm, sandy, moist soils.
Organic treatment
Pour soapy water into tunnels to bring them to the surface, then collect and kill them. Beneficial nematodes watered into the soil may reduce young ones.
Prevention
Keep lawns healthy and avoid overwatering. Protect seedbeds with collars or netting at soil level, and do not leave lights on at night, which draws adults.
Chemical treatment (use with care)
Use an insecticide bait or soil treatment labelled for mole crickets, applied in the evening to young nymphs, following the label.