Snowball leaf beetle
| Snowball leaf beetle | ||||||||||||
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Snowball leaf beetle |
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| Pyrrhalta viburni | ||||||||||||
| ( Paykull , 1799) |
The snowball leaf beetle ( Pyrrhalta viburni ) is a beetle from the family of leaf beetles (Chrysomelidae).
features
The snowball leaf beetle reaches a length of four to six millimeters and is brown in color. The body is elongated and widest in the rear third. There are dark spots on the middle of the pronotum and its edges, as well as on the shoulder bump and the crown of the head. The underside of the body is yellowish-brown, the upper side is provided with fine, light, close-fitting hairs. The head reaches almost the width of the adjoining pronotum. The pronotum is only slightly punctured, but the elytra are dense.
The larvae reach a length of about ten millimeters. They are yellow-green in color and have numerous warts.
The eggs are about a millimeter in diameter and light brown.
Similar species
Species of the genus Galerucella are similar to the snowball leaf beetle . In the representatives of this genus occurring in Europe, the undersides of the body are darkly colored.
Occurrence
The snowball leaf beetle is native to the western Palearctic . Its distribution area extends in the north to the south of Norway , in central Sweden and in the north of Finland . The snowball leaf beetle is only found locally in the British Isles . The species is not represented in the Mediterranean region . It is believed that it was introduced into North America in 1947 via imported nursery goods.
Way of life
The species lives exclusively on snowball species ( Viburnum ); mainly on common viburnum ( Viburnum opulus ), where the female lays five eggs in small depressions from August onwards, which she has previously gnawed in young viburnum branches. These depressions have a depth of about one millimeter and a diameter of about three millimeters. After the eggs have been laid, the clutch is closed with a secretion and a mixture of pegs and excrement . In total, the female lays around 250 to 500 eggs. They overwinter and the larvae hatch from April to May. The larvae develop for around four to five weeks and eat irregular holes between the leaf veins in the leaves. Pupation takes place in a cradle two to five centimeters below the ground. The beetles can be found from June to September, only one generation is formed. If the beetles are disturbed, they either immediately fall to the ground or fly away.
Occasionally it comes to mass reproductions, in which case the leaves of the food plants are completely skeletonized. The infected shrubs form a second leaf shoot after a short time, but their development is impaired.
swell
Individual evidence
- ↑ a b Jiři Zahradník, Irmgard Jung, Dieter Jung et al .: Käfer Central and Northwestern Europe , Parey Berlin 1985, ISBN 3-490-27118-1
- ↑ Plant protection problems : help with diagnosis. Weihenstefan University of Applied Sciences information service, January 2006 ( memento from February 10, 2013 in the web archive archive.today ).
- ^ National Resources Conservation Service: Plant Guide. (PDF; 107 kB) United States Department of Agriculture, accessed April 23, 2008 .
literature
- Edmund Reitter : Fauna Germanica - The beetles of the German Empire. Volume 4 p. 138, KG Lutz, Stuttgart 1912.
- Edmund Reitter: Fauna Germanica - The beetles of the German Empire. 5 volumes, Stuttgart KG Lutz 1908–1916, digital library volume 134, Directmedia Publishing GmbH, Berlin 2006, ISBN 3-89853-534-7 .
Web links
- Pyrrhalta viburni at Fauna Europaea