|Gryllotalpa brachyptera, Victoria, Australia|
|Distribution of the 3 main genera of Gryllotalpidae|
The mole crickets are the family Gryllotalpidae, in the order Orthoptera (grasshoppers, locusts and crickets). Mole crickets are cylindrical-bodied insects about 3–5 centimetres (1.2–2.0 in) long, with small eyes and shovel-like forelimbs highly developed for burrowing.
Mole crickets vary in size and appearance, but most of them are of moderate size for an insect, typically 3–5 cm long. They are muscular, as one may verify by holding one in the hand; they are inoffensive, but the confined insect will try to dig its way out with considerable force and they can deliver a harmless, albeit painful bite. The abdomen is rather soft, but the head, forelimbs, and prothorax are heavily sclerotised. The hind legs are shaped somewhat like the legs of a true cricket, but are more adapted for shoving while digging, rather than leaping, which they do rarely and poorly.
Most species of mole cricket can fly powerfully, if not with agility or frequency. Usually they fly only when moving long distances, such as when changing territory, or when females are searching for singing males. The adults of some species of mole cricket may fly as far as 8 kilometres (5.0 mi) during the mating season. Mole crickets are active most of the year, but spend the winter in hibernation. Last-stage juvenile insects have short wingpads where adult wings develop. Their appearance varies by species, but they are universally very tubular in shape and have short, powerful digging front legs consistent with their burrowing habits. Males have forewings with a scraper that, when rubbed against a file on the other wing, produces a pulse of sound; repeating this action produces a chirp (short sequence) or trill (long sequence). Some loosely resemble grasshoppers or very large ants or dark-colored "termites" when wings are short.
Mole crickets are relatively common, but because they are nocturnal and spend nearly all their lives underground in extensive tunnel systems, they are rarely seen. Mole crickets amplify their song by chirping in a burrow carefully sculpted into the shape of a double exponential horn, which acts as a megaphone. They inhabit agricultural fields, lawns and golf courses. They are present in every continent with the exception of Antarctica.
In some places, mole cricket numbers are declining due to soil erosion and habitat destruction. The nematode Steinernema scapterisci kills Scapteriscus mole crickets by introducing bacteria into their bodies, causing an overwhelming infection.
In human culture
In Zambia, Gryllotalpa africana is held to bring good fortune to anyone who sees it. The mole cricket is locally known in Latin America as "paquinha", "jeguinho", "cachorrinho-d'água", or "cava-chão" (genera Scapteriscus and Neocurtilla) and is said to predict rain when it digs into the ground.
There are several genera of mole cricket, separated into tribes:
- tribus Gryllotalpini
- tribus unknown (fossil taxa)
- Larra bicolor – parasitoid of Scapteriscus
- Walker T. J.; Nickle D. J. "Introduction and Spread of Pest Mole Crickets: Scapteriscus vicinus and S. acletus Reexamined" at Ann. Entomol. Soc. Am. 74: 158-163 (1981)
- Dawkins, The Selfish Gene, pg. 63
- "Genus Scapteriscus". IFAS Entomology. Retrieved 2015-05-10.
- Parkman, J.P.; Hudson, W.G.; Frank, J.H.; Nguyen, K.B.; Smart, G.C. Jr. (1985). "Establishment and persistence of Steinernema scapterisci (Rhabditida: Steinernematidae) in field populations of Scapteriscus spp. mole crickets (Orthoptera: Gryllotalpidae)". AGRIS 28 (2).
- Mbata 1999
- Fowler 1994
- "Mole Crickets Get Rid of These Invasive Pests". University of Florida. Retrieved 14 May 2015.
- De Foliart, Gene R. (1975–2002). "The Human Use of Insects as a Food Resource: A Bibliographic Account in Progress". Retrieved 14 May 2015.
|Wikimedia Commons has media related to Gryllotalpidae.|
|Wikispecies has information related to: Gryllotalpidae|
- Mole Cricket at Australian Museum
- Houston, Terry (2011) Information sheet: Mole Crickets at Western Australian Museum
- Prendergast, Amy (2012) "Solving the Mystery of the Hidden Callers of the Night" at Australian Wildlife Secrets
- Mole Cricket Knowledge Base at University of Florida / Institute of Food and Agricultural Sciences
- On the University of Florida / Institute of Food and Agricultural Sciences Featured Creatures website