Wood wasps

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Wood wasps
Giant wood wasp (Urocerus gigas), ♀, laying eggs

Giant wood wasp ( Urocerus gigas ), ♀, laying eggs

Systematics
Class : Insects (Insecta)
Order : Hymenoptera (Hymenoptera)
Subordination : Plant Wasps (Symphyta)
Superfamily : Wood wasps (Siricoidea)
Family : Wood wasps
Scientific name
Siricidae
Billberg , 1820
Subfamilies

The wood wasps (Siricidae) are a family of hymenoptera (Hymenoptera) and belong within this to the plant wasps . Together with the sawfly , the wood wasps are primitive representatives of the hymenoptera. The family is distributed worldwide with around 100 species, with the main distribution in forests of the northern temperate latitudes. 21 species are known in Europe, 8 of which are also found in Central Europe. Wood wasps cannot sting.

features

The adults reach a stately size for hymenoptera; the giant wood wasp ( Urocerus gigas ) is the largest hymenoptera in Central Europe with a body length of around 40 millimeters. Males are usually slightly smaller than females, and the two sexes often differ in their coloration ( sexual dimorphism ). The body of the wood wasps is elongated and cylindrical, the first tergite of the abdomen is divided in the middle. In both sexes the abdomen ends in a short point, in the females there is also a very long, fine, but strong ovipositor with paired saw bristles, which is covered by a two-part sheath. However, the ovipositor arises through the forward displacement of the abdominal abdominal segments further forward on the body. The sensors have 12 to 30 sections. The tibiae of the forelegs each have only one spur, the middle pair of legs lacks the preapical spurs.

The larvae are yellowish-white in color and, due to their endophytic way of life, have no eyes. Their mouthparts , however, are adapted to their food, wood, and are strong. Your thoracic legs are short, and your belly legs are absent.

Way of life

The females lay their eggs in the wood of trees by means of their ovipositor. Species of the subfamily Siricinae in the wood of conifers, those of the Tremecinae in the wood of deciduous trees. When laying eggs, the ovipositor is folded out of the sheath and the drill usually penetrates the wood as far as it will go. During this process, the animals are easy prey for predators. Female of the blue spruce wood wasp ( Sirex noctilio ), for example, can lay between 200 and 400 eggs in 80 to 100 egg tubes.

The larvae develop in the wood and gnaw passages, whereby the drill dust is pressed down with the abdomen. The development takes two to four years, but can also be greatly extended under unfavorable conditions. Their corridors can be up to 40 centimeters long. However, they do not feed directly on the wood, but on wood-decomposing fungi, such as the bleeding coniferous layer fungus ( Stereum sanguinolentum ), which are transferred to the wood by the females ( ectosymbiosis ). The oidia of these mushrooms are stored in special glands on the female's abdomen, the so-called mycetangia . The larvae pupate under the bark and do not build a pupa cradle. After hatching, the Imago bores into the open.

Systematics

The wood wasps are divided into two subfamilies, of which selected species are listed:

Economical meaning

A whole range of species occur as pests in forestry and fruit growing. In Australia and South America, species were also introduced through human plant imports. However, seasoned, old wood is not used for laying eggs. The more significant damaging effect, however, arises from the fact that, due to the long development time of the larvae, it can happen that the animals hatch out of already built-up wood, whereby they can gnaw their way through paint, plaster, fabric covers and even tin and lead coatings with their powerful mouthparts.

swell

Individual evidence

  1. ↑ Siricidae. Fauna Europaea, accessed December 10, 2008 .

literature

Web links

Web links

Commons : Wood Wasps  - Collection of images, videos and audio files