Pyrrhalta viburni
Snowball leaf beetle
The snowball leaf beetle ( Pyrrhalta viburni ) is a beetle of the family of leaf beetles ( Chrysomelidae ).
- 4.1 Notes and references
- 4.2 Literature
Features
The snowball leaf beetle reaches a length of four to six millimeters and is brown in color. The body is elongated and in the rear third widest. Dark spots are located on the middle of the pronotum and its edges, as well as on the shoulder bump and the vertex. The body underside is yellowish brown, the upper side is provided with fine, bright, adjacent hairs. The head reaches nearly the width of the adjoining pronotum. The pronotum is dotted only low, wing-coverts, however, tightly.
The larvae reach a length of approximately ten millimeters. They are colored yellow-green and carry numerous warts.
The eggs have a diameter of about one millimeter and are light brown.
Similar Species
Similar to the snowball leaf beetles are species of the genus Galerucella. The representatives of this genus occurring in Europe, the body undersides are dark colored.
Occurrence
The snowball leaf beetle is native to the Western Palearctic. You can observe this in the north to the south of Norway, in the middle of Sweden and the north of Finland. In the British Isles the snowball leaf beetle is only found locally. In the Mediterranean region, the species is not represented. It is believed that it was introduced in 1947 in North America via imported nursery stock.
Way of life
The species lives exclusively to snowball species ( Viburnum ); mainly to the ordinary (Viburnum opulus ), where the females from August put five eggs in small depressions which it has previously been gnawing in young snowball branches. These recesses have a depth of about one millimeter and a diameter of about three millimeters. The nest is closed after oviposition with a secretion and a mixture of Genagsel and excrement. Overall, the female lays about 250 to 500 eggs. They overwinter and the larvae hatch from April to May The larvae develop for about four to five weeks and eat irregular holes between the leaf veins in the leaves. Pupation takes place in a Puppenwiege two to five inches below the ground. The beetles can be found from June to September, there is only one generation formed. If the beetle is disturbed, then they can be either immediately fall to the ground or fly away.
Occasionally, outbreaks, in which case the leaves of the food plants are completely skeletonized. The infested shrubs form a second foliation after a short time, but are impaired in their development.