Larra
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| Fabricius , 1793 |
Larra is a genus of digger wasps (Spheciformes) from the Crabronidae family. 62 species are known worldwide, the main distribution area of which is the tropics. Thereare three species inthe Palearctic , one of which, Larra anathema , is also common in Europe. The genus is considered to be basal within the digger wasps, it shows many original features.
features
The grave wasps of the genus Larra are between 6 and 25 millimeters long. They have a black base color, most species show a red color on the gaster . In the species of the subgenus Cratolarra , which are mainly found in Asia , the legs are at least partially colored red. The legs of the subgenus Larra are colored black. The gaster and the propodeum are shiny, the head and chest are finely or coarsely spotted.
The legs are relatively short, especially in females. Some characteristics can only be used in females to distinguish them from other genera. This includes the legs, especially the shape of the last limbs of the tarsus . The tarsus claws are short and not toothed. The last tarsal link gradually widens towards the end and is not shaped like a scoop with parallel edges as in the closely related species Liris . Seen from the side, this tarsal link is only slightly curved and the underside is not as densely covered with short bristles as in Liris . In Liris , these features that Larra lacked could be adaptations for digging the tubes for the brood cells. The mandibles are not serrated as in other genera, in which the dentition is probably an adaptation for the transport of prey, which is omitted in the genus Larra .
These characteristics are fairly uniform in all species of the genus Larra , but some of them are also found in other genera. The most important differentiating criterion of the genus Larra to other genera, however, is their way of life.
Way of life
The brood is supplied with mole crickets (Gryllotalpidae). For this reason, experiments have been started on biological pest control with these digger wasps, for example to control the mole crickets that have been introduced to Hawaii or Puerto Rico . The females do not build their own nests, but use the duct system of the mole crickets. The crickets are tracked down from the surface, the female then invades their nest. The cricket usually escapes to the surface, where it is finally weakly stabbed and covered with an egg. If the cricket remains in its burrow, it will be taken outside after being stunned by the wasp. In total, a female can lay around 30 very small eggs in the course of her life. This is usually done between the legs on the ventral side of the prey's thorax . The cricket's paralysis usually lasts only a few minutes, after which it buries itself back in its nest. If they accidentally moult shortly after laying their eggs, the brood of digger wasps perish. This kind of brood care is considered very primitive. A larger number of eggs must be laid than with the closely related genus Liris , which builds its own nests and provides each brood cell with several crickets in order to achieve the same breeding success.
Systematics
The type species for the genus Larra is Larra ichneumoniformis Fabricius , 1793, originally described by Rossi , 1790, under the name Sphex anathema . Therefore this species is now called Larra anathema . Larra is the nominate form of the tribe Larrini and the subtribe Larrina within the subfamily Crabroninae . Larra is divided into the subgenus Larra (Cratolarra) , the species of which were previously often assigned to Liris , and Larra (Larra) , with more original characteristics.
supporting documents
Individual evidence
- ↑ Genus Larra ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. in Wojciech J. Pulawski: Catalog Sphecidae: Genera and Species . California Academy of Sciences, version of June 26, 2013 (PDF, English; 191 kB)
- ^ A b c Manfred Blösch: The digger wasps of Germany: way of life, behavior, distribution . 1st edition. Goecke & Evers, 2000, ISBN 3-931374-26-2 , pp. 222 f .
- ↑ Larra. Fauna Europaea, accessed July 23, 2010 .
- ↑ Richard Mitchell Bohart and Arnold S. Menke: Sphecid wasps of the world: a generic revision. University of California Press, 1976, pp. 235 ISBN 978-0-52002-318-5
literature
- Manfred Blösch: The digger wasps in Germany: way of life, behavior, distribution . 1st edition. Goecke & Evers, 2000, ISBN 3-931374-26-2 .
