Blue alder leaf beetle
| Blue alder leaf beetle | ||||||||||||
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Blue alder leaf beetle ( Agelastica alni ) |
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| Agelastica alni | ||||||||||||
| ( Linnaeus , 1758) |
The alder leaf beetle or blue alder leaf beetle ( Agelastica alni ) is a species from the family of leaf beetles (Chrysomelidae). It is the only one of its kind in Europe. Occasionally there is a mass occurrence in the animals in which alders can be completely defoliated.
features
The blue alder leaf beetle is six to seven millimeters long and has a somewhat stocky build. The widest part of the body, which is dense and finely structured in dots on top , lies behind the middle of the wing , the pronotum is narrower than this. It is rounded on the sides and has a hem on the sides, its pane is without impressions. The edge of the wing is clearly visible all around. The body of the animals is blue-black, dark blue, blue-violet or greenish in color. The antennae and legs are black. The head bears a distinctive impression between the antennae. The third part of the antennae is shorter than the fourth. The species can most likely be confused with blue-colored individuals of the ore-colored alder leaf beetle ( Linaeidea aenea ), which can be distinguished, however, in particular by their protruding shoulder ridges on the wing.
Occurrence
The species is widespread in the Palearctic and was introduced into the Nearctic . In Northern Europe the distribution extends as far as central Fennoscandia , in England the species is rare, as is also partly in the Alpine region. The animals colonize alders on the edge of water and in swamp areas. They are very common in general.
Way of life
Adults and larvae feed on alder leaves. The females lay clutches of 60 to 70 eggs on the underside of the leaves. After about two weeks, the black-colored young larvae hatch from them and then live together. Only later do they spread over individual leaves. Young larvae only eat one side of the leaves ( window damage ), older larvae eat holes. Pupation takes place three to five centimeters deep in the ground in a pupa cradle . The new generation of beetles hatch in July and feed on the alder leaves before overwintering in autumn. Only one generation is trained each year.
supporting documents
Individual evidence
- ^ Agelastica alni. Fauna Europaea, accessed August 13, 2009 .
literature
- Karl Wilhelm Harde, Frantisek Severa and Edwin Möhn: The Kosmos Käferführer: The Central European Beetles. Franckh-Kosmos Verlags-GmbH & Co KG, Stuttgart 2000, ISBN 3-440-06959-1 .
- Ekkehard Wachmann , Georg Möller, Reiner Grube: The Fauna Käferführer I - Beetles in and around the forest Fauna-Verlag, Nottuln 2006, ISBN 3-935980-25-6 .
- Jiři Zahradnik, Irmgard Jung, Dieter Jung et al .: Beetles of Central and Northwestern Europe. Parey, Berlin 1985, ISBN 3-490-27118-1 .
