Oak curlers
| Oak curlers | ||||||||||||
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Oak moth ( Tortrix viridana ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Tortrix viridana | ||||||||||||
| ( Linnaeus , 1758) |
The green oak ( Tortrix viridana ) is a butterfly ( moth ) from the family of Winder (Tortricidae).
description
The moths reach a wingspan of 16 to 24 millimeters. Their forewings are grass green to pale green and typical of the family, tapering at the rear end. A white fringed hem ends at the wing tips. Their hind wings are light gray and also have a white border. The head is yellowish, the chest green and the abdomen gray.
The young caterpillars are colored ocher gray to gray beige and have dark heads. The older animals are gray-green. The larvae go through five stages of growth.
The eggs are round and about 0.7 millimeters wide. They are light yellow at first and later turn brown.
Similar species
- Willow Kahneule ( Earias clorana )
Occurrence
The animals occur in the entire western Palearctic distribution area of the oak ( Quercus spec. ). They live in deciduous and oak forests and in other areas overgrown with oaks. They fly from May to summer.
Way of life
The females lay about 50 to 60 eggs on branches, preferably in the upper half of the tree canopy. You lay two eggs in pairs in a sticky mass. Dust adhering to this mass and algae growing on it are a good camouflage. The larvae only hatch after hibernating in May. They eat their way into buds that are already open because they cannot drill open buds that are closed. The young larvae eat young leaves, only in the third larval stage do they begin to spin leaves in order to eat them from the inside. The caterpillars feed mainly on oak leaves , but also on poplars ( Populus ), birches ( Betula ), maples ( Acer ), hornbeams ( Carpinus ), beeches ( Fagus ), willows ( Salix ), nettles ( Urtica ), blueberries ( Vaccinium ) and other plants. They need three to four weeks before they pupate wrapped in a leaf. After another three to four weeks, the finished moths hatch.
Flight and caterpillar times
The nocturnal and crepuscular moths fly in one generation in the upper areas of the treetops. But you can also find them during the day. Their development can be extended to two years in cold regions, but they can also fly in two generations in warm regions. The moths have a life expectancy of only 5 to 10 days.
Harmful effect
The oak moth is a feared forest pest . In Europe , for example in the large oak stocks of Westphalia and the Rhineland , there are repeated mass reproductions that lead to large parts of the herbaceous plants being devoured. This often happens in the lowlands, in loose forests or on individual, free-standing trees. The trees are severely weakened and can be affected by additional factors such as B. Drought die off. In addition, the growing leaves are often attacked by oak powdery mildew ( Microsphaera alphitoides ). Healthy oaks can even survive an infestation of several years. Some areas are infested differently each year, others only occasionally.
swell
Individual evidence
- ↑ Thomas Kaltenbach, Peter Victor Küppers: Kleinschmetterlinge. Verlag J. Neudamm-Neudamm, Melsungen 1987, ISBN 3-7888-0510-2 .
- ^ Karl Eckstein, Die Kleinschmetterlinge Deutschlands, Stuttgart 1933
literature
- Wolfgang Schwenke (Hrsg.) Among others: The forest pests of Europe. A manual in 5 volumes. Volume 3: Butterflies . Parey, Hamburg and Berlin 1978, ISBN 3-490-11316-0
- Fritz Schwerdtfeger : The forest diseases. Textbook of forest pathology and forest protection. 4th revised edition, Parey, Hamburg and Berlin 1981, ISBN 3-490-09116-7
Web links
- Ian Kimber: Guide to the moths of Great Britain and Ireland (English)
- Tortrix viridana (LINNAEUS, 1758) - Oak moth
- Tortrix viridana oak moth ( Memento from August 8, 2008 in the Internet Archive )
- www.schmetterling-raupe.de
- Tortrix viridana in Fauna Europaea