Parktown prawn

Description

The Parktown prawn, African king cricket or tusked king cricket (Libanasidus vittatus) is a species of king cricket endemic to Southern Africa. It is unrelated to prawns, Libanasidus being insects in the order Orthoptera-crickets, locusts and similar insects. The king crickets are not true crickets either: they belong to the family Anostostomatidae, whereas true crickets are in the Gryllidae. The insect gets its English name from the suburb of Parktown in Johannesburg, South Africa, where they are common. It is found throughout Namibia, and in the southern savanna and semi-arid regions of Angola. The Parktown prawn is related to the New Zealand tree wētā, which is also in the family Anostostomatidae. The Parktown prawn is held in low regard by many householders, but gardeners value them for controlling garden snail populations and attracting the hadeda ibis. The animal is omnivorous, with a diet that includes snails, other invertebrates, and vegetable matter. In urban environments, they will readily take food made available by suburban dwellers, including cat food and dog food and their droppings. Libanasidus vittatus was unknown within Johannesburg before the 1960s; the first known specimen was found in Barberton in 1899 by William Forsell Kirby. They only became prevalent after 1960, when Johannesburg began to expand rapidly in size. The reason for the increase in the insect's numbers is unclear, although they have done much better in an urban environment than in the wild, and it has been suggested that some ecological controlling factor is absent in its suburban habitat. The Parktown prawn is one of the larger invertebrates found around Johannesburg homes. A large specimen may grow to be 6 to 7 cm (2.8 in) or more, with long whip-like antennae extending to about the same length. The exoskeleton is orange to light brown, with darker brown or black stripes across the abdomen. The conspicuous markings probably are aposematic in effect. A large specimen can jump more than a metre high. The male insect sports a strong set of tusk-like projections on its mandibles, although the need for them is not fully explained. It is suggested that they may be used in sexual competition between males. The female has a well-developed sword-like ovipositor, through which she may lay between 80 and 200 eggs in damp or wet topsoil during the mating season.