Anostostomatidae
Anostostomatidae is a family of insects in the order Orthoptera, widely distributed in the southern hemisphere.[1] It is named Mimnermidae or Henicidae in some taxonomies, and common names include king crickets in Australia and South Africa, and wētā in New Zealand (although not all wētā are in Anostostomatidae). Prominent members include the Parktown prawn of South Africa, and the giant wētā of New Zealand. General characteristicsSome members of this family can be quite large: Parktown prawn can exceed 6 cm and tree weta can exceed 8 cm in length.[2] Some Australian and Asian anostostomatids have wings (e.g. Exogryllacris, Gryllotaurus, Transaevum), while most lack wings (e.g. Anostostoma, Hypocophoides, Penalva).[3][4] Males of some species have highly modified heads, which they use in male-male conflicts.[5] DietThe wētā of New Zealand, such as Hemideina, are mostly herbivores that feed on leaves, fruit and flowers, but may also scavenge recently killed invertebrates.[2] The ground wētā Anderus maculifrons eats a range of forest invertebrates.[6] The king crickets of Australia include generalised scavengers that consume various dead and decaying matter, specialised feeders (e.g. Exogryllacris feeds on fungal fruiting bodies growing on fallen trees) and predators of other invertebrates.[3] There is a record of an Australian king cricket preying on a funnel-web spider.[7] BehaviourAnostostomatidae are nocturnal. They generally become active soon after sunset.[3] Anostostomatidae communicate with sound, both through the air and as ground waves through soil, wood and sand. Adults of both sexes and also nymphs can produce sound. These crickets hear sound using foretibial tympana or other modifications to the tibiae, tarsi and perhaps prothorax.[5] As one example, Anostostoma can stridulate by rubbing its abdomen against its hind legs. The sides of the base of the abdomen have dense patches of short, sharp pegs, and there are similar pegs on the inner surfaces of the hind femurs. Sound is produced by these pegs rubbing together.[3] Anostostomatidae use various behaviours to defend against predators. Many hide in burrows during the day to avoid diurnal predators. If disturbed by a predator, they may jump away, stridulate, eject putrid-smelling faeces, bite, fly away (done by winged Exogryllacris and Gryllotaurus) or jump into water (done by Transaevum nymphs, which feed on streamsides).[3] Life cycleLike other orthopterans, Anostostomatidae go through the three stages of egg, nymph and adult. Life cycles in this family are often long, with egg development taking up to 18 months, nymphal development taking 1–3 years and involving 7-10 instars, and adults living for a year or more. Adult females may brood eggs and young nymphs in isolated chambers.[5] Taxonomy and evolutionAt least one Cretaceous fossil of an anostostomatid-like cricket is known from Australia but has not been described. The modern distribution of this family in the southern hemisphere has led to speculation that members of this group owe their distribution to the breakup of the ancient supercontinent Gondwana. This may be the case but evidence for the large scale if not total submergence of continental crust in the New Zealand and New Caledonian region in the Oligocene, indicates the possibility that wētā have arrived in these locations since re-emergence of land. The fact that anostostomatid crickets also occur on some Japanese islands supports this possibility.[citation needed] Subfamilies and generaThe Orthoptera Species File[8] lists the following; AnabropsinaeAuth.: Rentz & Weissman, 1973 – Americas, Africa, India, E. Asia, Australasia
AnostostomatinaeAuth.: Saussure, 1859 – Africa (including Madagascar), Australia, New Zealand
CratomelinaeAuth.: Brunner von Wattenwyl, 1888 – South America
DeinacridinaeAuth.: Karny, 1932 – New Zealand
LeiomelinaeAuth.: Gorochov, 2011 – S. America
LezininaeAuth.: Karny, 1932 – N. Africa, Middle East
Auth.: Gorochov, 1988 – Central & S. America, Africa, PNG
Subfamily not assigned
King crickets of South AfricaThe best-known species is the Parktown prawn, not to be confused with the well-known Koringkrieke or armoured ground crickets, which never have been in the family Anostostomatidae. Henicus monstrosus is a nocturnal anostostomatid. The males are unusual in their anatomy; their heads are disproportionately large and bear forward-directed prongs. They have extremely long, curved mandibles that are functional, but seem to play no part in the eating process.[9] Wētā of New ZealandSix genera of New Zealand wētā are part of the family Anostostomatidae:[4]
The cave wētā species belong to a different family, the Rhaphidophoridae. Literature
References
External linksWikispecies has information related to Anostostomatidae. |