Apple web moth
| Apple web moth | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Needled specimen of the apple spider moth |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Yponomeuta malinellus | ||||||||||||
| ( Zeller , 1838) |
The apple spider moth ( Yponomeuta malinellus ) is a butterfly ( moth ) from the family of spider and bud moths (Yponomeutidae).
features
The moths reach a wingspan of 16 to 23 millimeters. The head and appendages are white, the thorax is also white and has five black spots. The scales on the wing joint of the mesothorax ( tegulae ) are white, there is a black spot. The forewings are white and have 12 to 16 black dots, which are arranged in three irregular lines. The first fine black points can be found on the wing tip (apex). The middle of the wing is occasionally covered with a light gray. The black spots are arranged as in the plum web moth ( Ypsolopha padella ). The terminal fringed scales and the hind wings are gray. The legs are whitish, the front legs are darker in color on the upper side. The abdomen is gray.
The eggs are elongated oval, flattened and initially yellowish. Later they take on a brownish hue.
The crawler reach in the adult state, a length of 18 to 25 millimeters. The head, prothoracic and anal plates are blackish. The caterpillar body is yellowish gray, a subdorsal line of black dots is on each side of the body with one spot per segment. The spots are not divided. The belly legs are black. Young caterpillars are whitish in color.
The pupae initially have a greenish brown color, later they are pale brown. The head, antennae, mesothorax, metathorax, legs and the back of the last three abdominal segments are dark brown. The Kremaster is similar to that of the plum web moth, but is a bit slimmer. Two rows of bristles are arranged in a straight line, with the middle pair of bristles being slightly shorter than the others.
Similar species
The apple web moth differs from the plum web moth ( Yponomeuta padella ) by the white basic color of the forewings. Furthermore, the grayish fringed scales in Y. padella can be used for differentiation. The differences in genital morphology are rarely sufficient for reliable species identification.
distribution
The apple web moth appears in orchards. In the British Isles it can be found in the north to the Central Lowlands , in Ireland it is rare. In the rest of Europe the species is widespread, in the east the settlement area extends over Asia Minor and Azerbaijan to Manchuria and to Korea and Japan . The species is also represented in the USA .
Way of life
_-_Gespinst_(1).jpg)
The females lay up to 150 eggs in groups of 15 to 60 pieces on two to four year old shoots in the crown of apple trees ( crab apple ( Malus silvestris ), cultivated apple ( Malus domestica )). The egg clutch is located near the buds, it is covered with a yellowish mucus that hardens and forms a waterproof protective layer. This protective layer is initially reddish and later brownish. The egg caterpillars hatch within eight to 15 days and overwinter under the protective layer. In spring they crawl out from under the protective layer; As soon as the mean daytime temperature is around 12 ° C, they penetrate the buds and then mine in red-brown leaf mines in the upper part of the leaf. After the first molt, which takes ten to twelve days, the larvae give up the leaf mines and live on the leaves. This happens during the apple blossom. Web nests are built, which consist of two interconnected leaves. The larvae gnaw the leaf blade, leaving the nerve behind. They later live and eat gregariously in a web that can contain 200 to 300 caterpillars. The larval stage, including the wintering period, is 300 to 320 days, with 37 to 45 days being accounted for by the actual larval development in spring. The adult caterpillars pupate in a thick white silk cocoon when the apple trees shed the excess fruit. The cocoons hang closely together in the web of caterpillars. The pupae rest for eight to 15, sometimes up to 20 days.
The moths have a life expectancy of 20 to 30 days. During the day they are inactive and sit in shady places on the underside of the leaves. The flight phase begins immediately before dusk and ends as soon as it is dark. The moths fly to artificial light sources. Two weeks after hatching, the moths mate; after another five to six days, the females begin to lay eggs.
Flight and caterpillar times
The apple web moth forms a generation a year that flies from June to July (in the British Isles from July to August). The larvae can be found from May to June.
Harmful effect
The apple spider moth is a serious pest in horticulture, especially when there are no natural enemies. In the case of mass reproduction, a tree loses all leaves, fruit plants are thrown off and already formed fruits only reach a small size. Resistance to environmental influences is reduced. Insecticides are used to combat this , but they also endanger populations of harmless butterfly species. This even applies to pesticides based on Bacillus thuringiensis , which are only fatal for caterpillars. Biological control is becoming increasingly important, with natural enemies (see Parasites section) such as Ageniaspis fuscicollis (Hymenoptera: Encyrtidae ) being used.
Parasitoids
Various hymenoptera species parasitize on the larvae of the apple spider moth . Specifically, these are representatives of the parasitic wasps (Ichneumonidae), ore wasps (Chalcidoidea: Eulophidae, Pteromalidae), Encyrtidae , caterpillar flies (Tachinidae), and meat flies (Sarcophagidae). An overview of the species can be found in Gençer 2003 and in the literature cited by it.
Taxonomy
Synonyms
The apple web moth is known in the literature under the following synonyms:
- Hyponomeuta malinellus Zeller, 1838
The type locality of the apple web moth is Głogów in Poland (formerly Glogau or Groß-Glogau).
swell
Individual evidence
- ↑ a b c A. M. Emmet (Ed.): The Moths and Butterflies of Great Britain and Ireland. Volume 3: Yponomeutidae, Roeslerstammiidae, Epermeniidae, Schreckensteiniidae, Coleophoridae, Elachistidae. Harley Books, 1996, ISBN 0-946589-43-7 .
- ↑ a b c E. I. Ovsyannikova, I. Ya. Grichanow: Yponomeuta malinellus Zeller - Apple Ermine Moth. In: AN Afonin, SL Greene, NI Dzyubenko, AN Frolov (eds.): Interactive Agricultural Ecological Atlas of Russia and Neighboring Countries. Economic Plants and their Diseases, Pests and Weeds. 2008. (online)
- ^ KT Schütze: The biology of small butterflies with special consideration of their nutrient plants and times of appearance. Handbook of Microlepidoptera. Caterpillar calendar arranged according to the illustrated German Flora by H. Wagner. Verlag des Internationale Entomologische Verein e. V., Frankfurt am Main 1931. (online in the Lepiforum)
- ↑ Lütfiye Gençer: The Parasitoids of Yponomeuta malinellus Zeller (Lepidoptera: Yponomeutidae) in Sivas. Turk. J. Zool. 27 (2003) 43-46
- ^ Yponomeuta cagnagella (Huebner 1813). Fauna Europaea, Version 1.3, April 19, 2007 , accessed December 30, 2008 .
Web links
- Lepiforum eV taxonomy and photos
- Ian Kimber: Guide to the moths of Great Britain and Ireland (English)
- www.schmetterling-raupe.de