Zeiraphera griseana
Caterpillar on a larch
The gray larch bud moth ( Zeiraphera griseana; Syn: Zeiraphera diniana ) belongs to the family of the winder. He is one of the forest pests, which occurs at all stages of growth of spruce. However, particularly severe damage he causes to the spread in the Alps European larch and changes in the pine - larch forest over on the stone pine, which he also damaged heavily.
- 5.1 Notes and references
- 5.2 Literature
Features
Imago
The Grey larch has long, narrow forewings, which are light gray, light and dark brown mottled usually. However, color variations are observed occasionally, the lighter to almost white forewings have.
The rear wing of the Grey larch bud moth are broader than the forewing. Their color is a brown-gray; the wing tips are rounded pointed. On both pairs of wings, which have a wingspan 18-20 mm, the curlers wearing a pale gray fringe that is missing only on the front edge of the leaf.
Caterpillar and chrysalis
The caterpillars of the gray larch bud moth are initially black. Their body color develops with age to a dirty green back, interrupted by dark green vertical stripes. The legs of the track, however, remain black during this development process. Shortly before pupation the caterpillars again assume a darker color, weobei the formerly green areas change over a brown towards a black. Shortly before pupation the caterpillars have reached a length of 15 to 19 mm.
The doll is about eight millimeters long and brown to red - brown color.
Synonyms
- Zeiraphera diniana Guenée, 1845
Dissemination
In addition to northern Siberia the main distribution area of the gray larch bud moth is the Alps. He is to be found there, especially at altitudes 1600-2100 meters above sea level. Fund reports, there are also at an altitude of 500 meters. Reports of feeding damage are from the Pyrenees, England, Japan and Alaska. Attacks are a great diversity of trees. Apart from the European larch and Scots pine and Norway spruce ( Picea piceus ) is attacked.
Way of life
The night-active moths are observed in the months of July to September. During the day the moths remain with the typical roof-like wrapper for folded wings in the treetops.
Ecology
Together with the Swiss stone pine is the European larch the pine - larch forest, the typical forest type of the upper tree line in extreme high mountain regions. However, there are also numerous mountain forests, which consist of pure larch stands. They relate mainly Hangfußbereich the mountains and on easily accessible radiation- exposed slopes. This current distribution image of pure larch stocks goes back to a large extent on the centuries- long influence of mountain forests by man. Without human intervention, the schattenverträglichere Zirbelkiefer had the light- hungry larch about the natural forest succession gradually displaced. Where mountain areas, however, offered to grazing, man has deliberately knocked the stone pines and spruces. The result in this way are light-flooded forests that were suitable similar to the oak woods used for the acorns of the lowlands for grazing.
The alpine pasture economy is now only of secondary importance; so would win a greater share of the existing trees in the mountain forest through natural forest succession the stone pine again. In fact Zirbelkiefern form in many regions now a second tree layer under the bright canopy of larch. Studies of Friedrich -Karl Holt Meier show that by the Grey larch a new ecosystem has originated from a hitherto existing stability here, which prevents a predominance of stone pine. This is mainly due to the influence of the Grey larch bud moth. The Grey larch shows every few years a proliferation, in which the larches are stripped bare. Stand larch them are no longer available, change the caterpillars of the larch bud moth on the Zirbelkiefernbestand and destroy its needles also. While larch usually do not die by a Lärchenwicklerbefall that Zirbelkiefern suffer very persistent under this attack. Weakened Zirbelkiefern are then susceptible to attack by other pests such as the genuine Kiefernrüssler that Arvenwolllaus or the bark beetle, then die or develop into Kümmerwuchsbäumen.