Plum web moth
| Plum web moth | ||||||||||||
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Plum moth ( Yponomeuta padella ) |
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| Scientific name | ||||||||||||
| Yponomeuta padella | ||||||||||||
| ( Linnaeus , 1758) |
The plum web moth ( Yponomeuta padella ) is a butterfly ( moth ) from the family of web and bud moths (Yponomeutidae).
features
The moths reach a wingspan of 19 to 22 millimeters. The head and the attachments are white. The thorax is white or grayish white and has five black spots. The scales on the wing joint of the mesothorax each have a black spot. The forewings are pale grayish white or gray and provided with 16 to 19 black spots, which are arranged in four rows. The subcostal line consists of three or four spots in the first half. The second row consists of five spots and runs from the first third of the wing to the outer edge of the wing. Another with four to six spots runs above, another with four to seven spots below the wing fold. The hind wings are gray. The legs are whitish, the front legs are darker on top. The abdomen is gray. Moths whose larvae have eaten on blackthorn ( Prunus spinosa ) tend to be darker in color.
The eggs are rounded and flattened. They are yellow at first, later they turn brown.
The fully grown caterpillars reach a length of 15 to 22 millimeters. The head is black, the prothoracic and anal plates are blackish. The caterpillar body is greenish 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 are seven to eight millimeters long. The head, thorax, wing sheaths, and the last three abdominal segments are pale or yellowish brown. The pairs of bristles on the Kremaster are arranged in an almost straight line, two pairs of bristles are the same length.
Similar species
The plum web moth is part of a species complex whose representatives can only be distinguished from similar species with great difficulty, even in genital examinations . From the apple spider moth ( Yponomeuta malinellus ), the plum spider moth can best be distinguished on the basis of the food plant, but that too is not always reliable. Usually the plum spider moth differs from the apple spider moth by the grayish fringed scales, while the grayish pollination of the forewings distinguishes it from the peacock butterfly moth . In Yponomeuta rorella (Hübner, 1796) the grayish pollination has a slightly different structure. According to Povel 1984, the number of feeler segments can be used to differentiate. So has Y. padella 51 to 57, Y. malinellus 50 to 56, and Y. cagnagella 56-65 sensor members.
distribution
The plum web moth is widespread in Europe, you can find it in all biotopes in which the food plants occur. In the area of the former Soviet Union , it is widespread in the European part in the north to the Saint Petersburg area. In the east, the plum web moth is widespread in Transcaucasia , in southern Kazakhstan and in Central Asia. The species was introduced in North America .
In Northern Ireland , Y. padella first appeared when defoliation was observed on hedges of common hawthorn ( Crataegus monogyna ) and blackthorn ( Prunus spinosa ) in 1972 . Up to this point there was no evidence of Y. padella , although Y. malinellus was local. In parts of the Republic of Ireland , the spread of Y. padella has reached epidemic proportions within 30 years. In a period of 10 years, the species colonized an area of more than 600 km² and continues to spread. Within this area the populations appeared randomly, most hedges were not infested, while in infested areas the populations lasted for many years.
Way of life
The females lay the eggs in scale-like clusters on blackthorn ( Prunus spinosa ), hawthorn ( Crataegus ), plum or cherry ( Prunus ). The eggs are usually laid on the thorns, but they are occasionally found on the trunk. They are covered with a yellowish slime that hardens and forms a waterproof protective layer. On average, a clutch contains 50 eggs, but the number varies considerably.
The majority of the caterpillars hatch within three weeks, some overwinter under the waterproof protective layer created for the eggs. In May they crawl out from under the protective layer and feed on buds or young leaves. In contrast to those of the apple web moth, the larvae of the first larval stage do not live as leaf miners , but immediately sociable in a web. The adult caterpillars pupate together in loose, gray cocoons in a gathering web. The cocoons are distributed irregularly in the caterpillar web.
Flight time
The plum web moth forms a generation a year that flies from June to July (in the British Isles from July to August). The larvae hatch in May. The moths are nocturnal, with the flight phase beginning immediately before dusk. It ends as soon as it is dark. The moths come to light.
pest
The larvae of the plum spider moth feed on a variety of stone fruit varieties and can cause considerable economic damage in horticulture. The fallen leaves can be collected and destroyed to combat it. In Eastern Europe , the parasitoid Ageniaspis fuscicollis Dalman, 1820 ( Hymenoptera : Encyrtidae ) is used for biological control. This parasitoid has no noticeable influence on the population density in Ireland , instead a previously unknown microsporidium was discovered that infects the intestinal cell walls of the host and kills it.
Parasitoids
Various hymenoptera species (Hymenoptera) parasitize the larvae of the plum moth . The most important are Ageniaspis fuscicollis , Elasmus nudus (Nees, 1834), Tetrastichus evonymellae (Bouche, 1834) (Hymenoptera: Eulophidae ). An infection with the bacterium Bacillus subtilis is also mentioned in the literature .
Systematics
In the literature, the plum moth is known by the following synonyms:
- Hyponomeuta diffluellus Heinemann, 1870
- Yponomeuta rhamnellus Gershenson, 1974
- Phalaena (Tinea) padella Linnaeus, 1758
- Hyponomeuta variabilis Zeller, 1844
Individual evidence
- ↑ a b c d e 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
- ↑ GDE Povel: The identification of the European small ermine moths, with special reference to the Yponomeuta padellus-complex (Lepidoptera, Yponomeutidae). Proc. K. ned. Akad. Wet. (C), 87 (2): pp. 149-180
- ↑ a b c EI Ovsyannikova, I. Ya. Grichanow: Yponomeuta malinellus Zeller - Apple Ermine Moth. In: AN Afonin, SL Greene, NI Dzyubenko, AN Frolov (eds.). 2008. Interactive Agricultural Ecological Atlas of Russia and Neighboring Countries. Economic Plants and their Diseases, Pests and Weeds [Online]. online: http://www.agroatlas.ru/en/content/related/Lonicera_edulis/
- ^ A b D. J. Mowat, S. Clawson: Natural control of the Small Ermine Moth Yponomeuta padella (L.). Agriculture, Ecosystems & Environment, 52 (2-3), pp. 92-103, 1995. doi : 10.1016 / 0167-8809 (94) 00547-R
- ^ 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. Frankfurt am Main (publishing house of the International Entomological Association e.V. 1931). Online in the Lepiforum
- ↑ a b Yponomeuta padella (Linnaeus 1758). Fauna Europaea, Version 1.3, April 19, 2007 , accessed on December 21, 2007 .
