These nocturnal insects have a head like a prawn and feet like a mole, are as long as your finger and their song is as loud as a rock concert or leaf blower. Would you be able to identify a mole cricket?
Common name: Mole Crickets
Scientific name(s): 11 species of Gryllotalpa species over the wetter parts of Australia, and the introduced Changa Mole Cricket Scapteriscus didactylus, around Newcastle.
Description: Large brown crickets up to 5cm long, with short legs and shovel-like forefeet, and two long flexible cerci at the end of the abdomen. The head, thorax and front legs are stiff and robust, but the abdomen is soft. Wings may be small or absent. In Western Australia, they may be mistaken for the unrelated sandgropers, which are longer than mole crickets and yellow-brown rather than dark brown.
Geographic distribution: Found on all continents apart from Antarctica. Introduced species have become widespread pests in North America and other parts of the world.
Habitat: Almost always nocturnal, and infrequently seen above ground, but females may be attracted to lights when seeking a mate, and both sexes may enter a house if flooded out of their burrow by heavy rain.
Males dig tunnels designed to amplify their call, which can reach 115 decibels at the mouth of the tunnel. Calling starts at dusk and continues for a few hours. Females can tell whether the tunnel was dug in moist or dry soil, and prefer the latter. Females then guard the eggs until hatching.
Pest status: Mole Crickets may be herbivorous, carnivorous, or omnivorous, and their feeding and burrowing can damage lawns or kill seedlings. Introduced species overseas are significant turf pests, especially in late spring and summer when the nymphs are most active. If handled roughly, they may also spray a foul-smelling fluid from glands near the anus. Males calling at night can be irritating at peak volume.
Treatment: Native mole crickets have many native predators and parasites, and biological control has been attempted in some parts of the world against introduced species. Pesticides including Imidacloprid sprays, granules, or baits may also be used, on nights when temperature exceed 16oC, and after irrigating the area to encourage mole crickets to come up to feed.
Daniel Heald, technician and entomologist