Seed owl
| Seed owl | ||||||||||||
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Common Owl (Agrotis segetum) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Agrotis segetum | ||||||||||||
| ( Denis & Schiffermüller , 1775) |
The turnip moth ( Agrotis segetum ), also cereal turnip moth called, is a butterfly of the family of cutworms (Noctuidae).
features
The moths are small to medium-sized and have a wingspan of 30 to 46 millimeters. The basic color of the forewings is very variable and ranges from a light gray to almost black. The drawing of the forewings is also extremely variable and ranges from sharply drawn to almost no drawing. The heavily drawn specimens have a wavy or jagged inner transverse line, a jagged wavy line and a jagged hem line as well as two kidney-shaped blemishes. There are all transitions up to copies almost without drawings; hardly any individual is the same as another. The antennae of the male, which are strongly double-combed in the lower half, serve to distinguish them from other similar species. The hind wings are light to slightly transparent. In females they are often bordered gray. On average, the females are darker in color.
The eggs are greenish to yellowish and slightly ribbed lengthways.
The caterpillars are glossy gray to slightly reddish. The back line is bordered light and dark. The brownish secondary ridge lines are relatively wide. The stigmas are colored black; they lie in a narrow, darker shoulder. The ventral side is light, the head brownish.
The doll is light red-brown. Two short spikes sit on the pointed cremaster .
Geographical distribution and habitat
With the exception of northern Scandinavia, northern Russia, the European Caucasus and some North Sea islands , the common owl is native to almost all of Europe; its distribution extends into tropical Africa and far into Asia . The exact distribution of the migrant species is still unclear. It is also found in South Africa , but was probably introduced there.
The habitat of the sowing owl are mountain and valley meadows in the area of forest areas, steppe heaths and grassy dwarf shrub heaths, as well as dry grass on fields and dirt roads . Today the main occurrences are mainly in fields and vegetable growing areas and in gardens. The species occurs from the lowlands to the highest areas of the German low mountain range, even if it is much less common there. The seed owl is common in Germany.
Way of life
The seed owl usually forms two generations per year in Central Europe. The first generation moths fly from May to July; the second generation moths can be observed from August to September. Moths that fly very late (October / November) can represent a third generation. The moths are nocturnal and are attracted to light. They visit flowers and can also be baited with sugar. The eggs are deposited on leaves in small to medium-sized groups.
The caterpillars are extremely polyphagous and feed on the roots and leaves of many plant species, including crops such as cereals , potatoes , carrots and lettuce . Spruce ( Picea abies ) and larch ( Larix decidua ) are also among the food plants . The caterpillar overwinters and pupates in a burrow in April.
Development time in breeding
For breeding at 24 ° Görnitz gives the following shortest development time (a total of five larval stages are formed): Embryonic development in the egg 5 days, L1 4 days, L2 4 days, L3 6 days, L4 6 days, L4 (including prepupa) 11 days . The pupil rest is slightly different between 14 and 16 and 15 to 18 days in males and females. Thereafter, the shortest duration of a generation is to be set at around 2 months. He gives the average life expectancy of the moths at 10 days, max. with 23 days on. From one female max. 1514 eggs laid. There is no diapause under breeding conditions, but occasionally a developmental inhibition is observed, which probably corresponds to a diapause. Svensson et al. (1998) give e.g. In some cases slightly different values: average lifespan of the moths 16 to 19 days. Just a few hours to a few days after hatching, the moths mate. The first eggs were found three days after hatching; most of the females had laid their eggs after seven days at the latest. In total, the females laid an average of 620 ± 60 eggs. The egg caterpillars hatched after about five days. According to Bongers & Weismann, the development time is also heavily dependent on temperature and diet. They observed a larval phase of only 21 to 28 days at 30 °, which increased to 81 days at 18 °. The lower temperature limit at which the larvae still developed was slightly above 11 °.
Harmful effect
The caterpillar is seen as a pest , especially in southern Europe , as it also eats the roots of cultivated plants (winter cereals, lettuce, vegetables, cabbage, beets, potatoes). In the past there were also mass reproductions and thus harmful infestations in Central Europe.
swell
Individual evidence
- ↑ Red lists at Science4you
- ↑ Fibiger (1990: pp. 84/5)
- ^ A b Walter Forster , Theodor A. Wohlfahrt : The butterflies of Central Europe. Volume 4: Owls. (Noctuidae). Franckh'sche Verlagshandlung, Stuttgart 1971, ISBN 3-440-03752-5 .
- ↑ Axel Steiner in Ebert (1998: pp. 533-536)
- ^ K. Görnitz: The mass rearing of caterpillars of the winter sow owl (Agrotis segetum Schiff.) For laboratory experiments. Anzeiger für Pestkunde, 24 (5): 65-68, 1951 doi : 10.1007 / BF02283412
- ^ Mats GE Svensson, Elisabeth Marling and Jan Lofqvist: Mating Behavior and Reproductive Potential in the Turnip Moth Agrotis segetum (Lepidoptera: Noctuidae). Journal of Insect Behavior, 11 (3): 343-359, 1998
- ↑ Jürgen Bongers and Ludovit Weismann: The influence of temperature on the nutrition of Agrotis segetum (Lepidoptera). Journal of Insect Physiology, 17: 2051-2059, 1971 doi : 10.1016 / 0022-1910 (71) 90166-1
literature
- Günter Ebert, Axel Steiner: The butterflies of Baden Württemberg Volume 7, Nachtfalter V (Owls (Noctuidae) 3rd part), Ulmer Verlag Stuttgart 1998. ISBN 3-8001-3500-0 .
- Michael Fibiger: Noctuidae Europaeae Volume 1 Noctuinae I. 208 S., Entomological Press, Sorø 1990 ISBN 87-89430-01-8 .
- Manfred Koch : We determine butterflies. Volume 3: Owls. 2nd, expanded edition. Neumann, Leipzig / Radebeul 1972, DNB 760072930 .
