Larra bicolor
| Larra bicolor | |
|---|---|
 |
|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Hymenoptera |
| Family: |
Crabronidae Latreille, 1802 |
| Genus: |
Larra Fabricius, 1793 |
| Binomial name | |
|
Larra bicolor (Fabricius, 1804) |
|
Larra bicolor is a parasitoid wasp native to South America. It was introduced into Florida as a biological pest control of invasive mole crickets.
Adult females of this species are about 22 mm long, with the males somewhat smaller. The head and thorax are black, with silver markings on the head; the abdomen is red. The wings are variable in color, of a dusky hue.
These wasps feed on nectar as adults, with the shrubby false buttonweed (Spermacoce verticillata) preferred. Females hunt mole crickets in the genus Scapteriscus, stinging them on the underside to paralyze them for several minutes. A single egg is deposited between the first and second pairs of legs. The wasp then flies off, and the cricket returns to its burrow. Nymphs as well as adult crickets are attacked, as long as they are large enough.
Upon hatching, the larva feeds upon its host, eventually killing it. It pupates within 12 to 30 days (depending on temperature), forming a cocoon in the remains of the cricket by gluing sand grains together. The pupal phase may be as short as 50 days, but the pupa may enter diapause in the winter, delaying emergence for months. Adults are solitary and do not form nests or colonies.
Other than the winter diapause mentioned above, there is no seasonal component to wasp activity. Several generations of wasps may occur in a year, one of the facets that allows these wasps to out-reproduce their hosts, an important attribute for a successful biological control agent.
Non-native mole crickets arrived in Puerto Rico, at least as early as the 18th century, probably by flight, and as early as 1899 in the southeastern United States, probably as contaminants of ship ballast. They became serious pests, damaging crops and pasture- and turfgrasses. Although the related L. analis attacks the native northern mole cricket, it does not attack non-native species. In an early example of biological pest control, L. bicolor was introduced into Puerto Rico in 1938, where it became successfully established. This suggested the possibility of its use on the mainland; however, failed attempts and the development of chlordane pesticide in the 1940s brought an end to these efforts.
...
Wikipedia