Ibaliidae

Ibalia aprilina

The Ibaliidae are a small family of Hymenoptera. They are classified in the Gallwespenartigen ( Cynipoidea ) within the Legimmen. Worldwide, about twenty species have been described in three genera.

Features

It is relatively elongated, medium sized animals with a body length of 10 to about 30 millimeters, whereas the females are larger than males. The body length within a species is always strikingly variable and highly dependent on the processing conditions. Most species are quite rich in contrast drawn with black combined with red or yellow tints, the wings sometimes have spots or bands. In the body form a relatively compact and high, strong and sculpted sklerotisiertes mesosoma ( Hull region ) falls on in conjunction with an oversight in extremely narrow, in lateral view elongated oval abdomen. This form of the abdomen is often described as " knife-shaped ". The long ovipositor of the female is hidden in the rest position in the abdomen. It forms here a complete loop and is enclosed in a membrane bag with ansitz forming muscles. The laying operation, this envelope is pulled together, whereby the tip of the ovipositor protrudes forward. At the top sit for long, threadlike antennae have 13 segments in the male 15, in the female. In the male the third antennal segment is extended and strikingly asymmetrical bent, it carries glands fields that are in the pairing of meaning. A characteristic and striking is always a transverse elevated ridge on the pronotum. This structure they have in common with the family of Liopteridae from which they can be distinguished ( at Liopteridae with deep dimples ) on the sculpture of Pronotumseiten. In addition, the Pronotumkiel in Ibaliidae has a characteristic indentation in the center line. On the hind legs, the legs ( femurs ) are strikingly shortened and no longer than the hips ( coxae ). The first Tarsalglied the hind feet ( tarsi ) is extended striking and twice as long as the other four together. The Flügeladerung corresponds to the usual scheme of Gallwespenartigen, the triangular boundary cell is strikingly elongated in the Ibaliidae. On the abdomen is usually the last segment is the longest.

Way of life

The larvae are parasitoids of all Ibaliidae larvae of wood wasps ( Siricidae ). The female bores with its ovipositor to the egg hidden deep in the woods or the first larval stage of its host and places it on its own egg. The location of the host is carried out by chemical means, for example, wherein the parasitoid the symbiotic fungus, the deposits the wood wasp with her egg in the wood, the smell detects. The drilling follows the bore of the wood wasp the female. The egg has, typical of all Gallwespenartigen, a charakterisches stalks on. This stalk region serves as a temporary home for the egg mixture when the egg is squeezed in the narrow passage of the ovipositor and protracted.

The larva eats within their living further and further monitoring at the host ( koinobionter parasitoid ). The Erstlarve has a striking shape with a tail yarn and thread-like side appendices at the first through twelfth segment. These larvae form was described as " polypodeiform ". The threads take on the growing larva relative to length and go up to the fourth larval stage lost. The larva of the fourth stage leaves the dying host. It has been notably large mandibles, but seems to take no more food. They pupate in the burrow of their hosts deep in the woods and puts it at no dream. The hatched imago must eventually gnaw through to the surface through the wood. It has this particularly strong, serrated mandibles. The development of the egg-laying until hatching takes normally between one and three years. Whether the Imago receives food, is unclear.

System

Within the Cynipoidea the Ibaliidae regarded as a morphologically original family. Yet there is no consensus about their exact position within the superfamily. Either they form a separate line of development, which branches off to the Austrocynipidae from the common trunk and would be a sister group of the remaining Gallwespenartigen, or form, with the Liopteridae a common lineage.

The family is divided into three living ( extant ) species:

• Ibalia, with two subgenera Subgenus Ibalia s.str. Parasitoids of wood wasp larvae in softwoods
• Subgenus Tremibalia. Parasitoids of wood wasp larvae in hardwoods

Dissemination

The genus Ibalia is spread all over the northern hemisphere ( holarctic ). It penetrates far to the south in East Asia before and achieved a kind ( Ibalia calimantanica ) on Borneo in the tropics. The genus Heteribalia lives in temperate East Asia. Hurry Ella catherinae is known only from New Guinea.

In Europe, three species have been reached by all even Central Europe:

• Ibalia leucospoides
• Ibalia rufipes, subspecies drewseni
• Ibalia Jakowlewi.

All species are in Central Europe as rare to very rare.

Economic Importance

Ibaliidae are antagonists of wood wasp larvae, which in part cause economic damage to forest trees and timber, and are therefore considered beneficial. It is significant especially the kind Ibalia leucospoides as predatory parasite of blue spruce wasp ( Sirex Noctilio ) and the giant wood wasp ( Urocerus gigas). The species was artificially introduced and settled where entrained Blue Spruce wood wasps have caused severe economic damage in pine forests, which go far beyond those in the original homeland for biological pest control to Australia, Tasmania, New Zealand, South Africa and South America. The first releases in Tasmania and New Zealand already made in the 1950s. The settlement is considered successful, it carries today to control the Holzwespenart. But she was not decisive in economic terms, this was achieved only later with the establishment of a parasitic nematode.

Swell

• Göran Nordlander, Zhiwei Liu, Fredrik Ronquist (1996 ): Phylogeny and historical biogeography of the family Ibaliidae cynipoid wasp ( Hymenoptera). Systematic Entomology 21 (2): 151-166.
• Frederick Ronquist (1995 ): Phylogeny and early evolution of the Cynipoidea ( Hymenoptera). Systematic Entomology 20: 309-335. doi: 10.1111/j.1365-3113.1995.tb00099.x
• Fredrik Ronquist (1999): Phylogeny, classification and evolution of the Cynipoidea. Zoologica Scripta 28: 139-164. doi: 10.1046/j.1463-6409.1999.00022.x
• Fredrik Ronquist & Göran Nordlander (1989 ): Skeletal morphology of an archaic cynipoid, Ibalia rufipes (Hymenoptera, Entomologica Scandinavica Supplement 33 Ibaliidae.
• Zhiwei Liu, Michael S. Engel, David A. Grimaldi (2007): Phylogeny and Geological History of the Cynipoid Wasps ( Hymenoptera: Cynipoidea ). American Museum Novitates 3583, 1-48.