Kingdom Animalia Suborder Ensifera Phylum Arthropoda Rank Species | Class Insecta Family Gryllotalpidae Genus Scapteriscus Order Orthoptera | |
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Similar Scapteriscus, Scapteriscus borellii, Orthoptera, Neocurtilla hexadactyla, Larra bicolor | ||
Scapteriscus vicinus bicho topo
Scapteriscus vicinus, the tawny mole cricket, is a species of insect in the mole cricket family, Gryllotalpidae. It is native to South America and also occurs in the southern United States where it was introduced accidentally around 1900.
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Description
Scapteriscus vicinus is a medium-sized mole cricket. Members of this genus are characterized by having two sharp claws and a blade-like process with a sharp edge on their forelegs. Other mole crickets have three or four claws. Its colour is yellowish-brown with a dark prothorax. It can be told from the rather similar Scapteriscus borellii by the fact that the two claws are almost touching at the base, whereas in S. borellii, they are widely separated. The song of S.vicinius, produced only by the males, is a loud trill with a pulse rate of 130 per second.
Distribution and habitat
Scapteriscus vicinus is native to South America. Since arriving in the United States, it has increased its range, which now extends from North Carolina to Louisiana and the whole of Florida. Though thought of primarily as a pest of turf and grassland, it also damages many crop plants including tomatoes, strawberries, vegetables, peanuts, sugar cane, tobacco and ornamental plants.
Ecology
Scapteriscus vicinus burrows in sandy soil creating galleries, usually in the upper 25 cm (10 in), the depth depending on the temperature and soil moisture content. In Florida the adults are active in spring and again in autumn, completing a single life cycle during the summer months and overwintering as a large nymph. S. vicinus is herbivorous and feeds on the roots and young shoots of plants, and also causes damage to plants through its burrowing activities. Breeding takes place in spring and autumn, with the male calling soon after sunset to attract a female. After copulation the female lays between 25 and 60 eggs in an underground chamber, the entrance to which is then blocked with soil. The eggs hatch some three weeks later. The nymphs take several months to develop fully, passing through eight to ten moults.
In an attempt to reduce the damage done by Scapteriscus mole crickets in Florida, biological pest control has been attempted using natural enemies introduced from South America. Larra bicolor is a parasitoid wasp which deposits larvae on adult mole crickets. The fly Ormia depleta acts in a similar manner, laying eggs on them; in both cases, the developing larvae devour the tissues of the host. The mole cricket nematode (Steinernema scapterisci) liberates a bacterium which causes sepsis and death to its host mole cricket.