Turnip Moth
Saateule ( Agrotis segetum )
- 5.1 Notes and references
- 5.2 Literature
Features
The moths are small to medium in size and have a wingspan from 30 to 46 millimeters. The ground color of the forewings is very variable, ranging from light gray to almost black. The drawing of the front wing is extremely variable, ranging from sharply drawn up almost without markings. The badly damaged specimens have a wavy or jagged inner transverse line, a serrated wavy line and a jagged hemline and two kidney-shaped stigma. There are all transitions up to almost visually marked specimens; hardly an individual are the same. To distinguish them from other similar species are for the probe of the male, which are strongly doppelkämmig in the lower half. The hind wings are bright and slightly transparent. In the female they are often edged with gray. On average, the females are darker.
The eggs are greenish to yellowish and weakly longitudinally ribbed.
The caterpillars are shiny gray to light reddish. The back line is edged with light and dark. The brownish side ridge lines are relatively broad. The spiracles are black in color; they are situated in a narrow strip darker side. The belly is bright, the head brownish.
The pupa is pale red. In the acute cremaster sit two short spines.
Geographical distribution and habitat
The Saateule is at home with the exception of northern Scandinavia, northern Russia, the Caucasus region and some European North Sea islands in most of Europe, their distribution extends up to tropical Africa and far into Asia. The exact distribution of the wandering nature is still unclear. It also occurs in South Africa, but there was probably introduced.
The habitat of the mountain and valley meadows Saateule are in the range of woodland, heathland and grassy dwarf shrub heaths and grasslands on the edges of fields and country lanes. Today, the main deposits are mainly in field and vegetable growing areas and in gardens. The species occurs from the lowlands in front up to the highest areas of the Central German Uplands, if it is there also a lot less often. The Saateule is often found in Germany.
Way of life
The Saateule forms in Central Europe usually two generations per year. The moths of the first generation fly from May to July; August-September, the moths of the second generation can be observed. Very late flying butterflies ( October / November) may be representative of a third generation. The moths are nocturnal and are attracted to the light. Visit flowers and can be baited with sugar. The eggs are deposited in small to medium sized groups on leaves.
The caterpillars live extremely polyphagous and feed on roots and leaves of many plant species, among which also crops such as cereals, potatoes, carrots, and salad are. Among the food crops are also spruce (Picea abies) and larch (Larix decidua). The caterpillar overwinters and pupates in April in a hole in the ground.
Development time in the breeding
For breeding at 24 ° Görnitz following shortest development time (in total 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 pupal period is slightly different from 14 to 16 and 15 to 18 days in males and females. Then the shortest duration of a generation with about 2 months shall be used. The average life expectancy of butterflies he gives 10 days, max. with 23 of days. From a females were max. 1514 eggs stored. It is not inserted diapause under farming conditions, but occasionally a developmental inhibition is observed, which probably corresponds to a diapause. Svensson et al. (1998) give z.T. slightly different values: average life span of the moths 16 to 19 days. Just a few hours to a few days after hatching is mated moths. The first eggs were found after only three days after hatching; most females had laid their eggs within seven days. Overall, the females laid an average of 620 - 60 eggs. After approximately five days the hatched Eiraupen. After Bongers & Weismann development Auer is also strongly dependent on the temperature and nutrition. They observed at 30 °, a larval phase of only 21 to 28 days, which increased at 18 ° to 81 days. The lower temperature limit at which the larvae were still developing, stood at just over 11 °.
Harmful effect
The caterpillar is mainly in southern Europe regarded as a pest because it eats inter alia, to the roots of crops ( winter cereals, salad, vegetables, cabbage, beets, potatoes). Previously, there were also outbreaks and thus harmful infestation in Central Europe.