Euxoa birivia
Euxoa birivia, males ( from Seitz, 1909)
Euxoa birivia, and occasionally unusual even called Lead Grey Erdeule, is a butterfly (moth ) from the family of cutworms ( Noctuidae ).
- 3.1 Development
- 5.1 Notes and references
- 5.2 Literature
Features
The moths have a wingspan of 34-41 millimeters. The front wings are on top of plain leaden gray. Cross lines and blemishes are light gray or slightly yellowish drawn, often indistinct. Ground color and markings vary only slightly. In contrast, the wing shape is surprisingly variable.
The spherical egg measures 0.8 millimeters in diameter. It is colored dirty yellowish white. Its surface is slightly longitudinally ribbed.
The Eiraupe (L1 ) has a slender habitus. It is yellowish white and has several orange wavy bands and longitudinal lines on the back. These are the rear end stronger. Head and neck shield are shiny black. The anal shield and the starting points of the bristles are gray-brown. In the L3 stage, the caterpillar is dirty gray-green. The orange longitudinal lines and bands on their backs are washed out and rather indistinct. Head and neck shield are shiny yellow ocher.
The adult caterpillar (L5 ) is about 40 millimeters long. She is dirty gray and has on the back of indistinct longitudinal white lines. The head is pale beige with a darker wetting. The neck plate is colored translucent light beige brownish, as is the anal shield.
The doll reaches a length of 18 to 20 millimeters. It is colored light yellowish brown, thin skin effect and is translucent. The rings of the abdominal segments are dark brown applied. The cremaster is occupied by two short, straight thorns.
Similar Species
For fresh moths is a confusion due to the lead- gray color with light gray drawing with Euxoa decora, which has a gray base color with darker drawing, hardly possible.
Geographical distribution and habitat
Euxoa birivia colonized the Alps and Pre-Alps regions of France ( including the high regions of Corsica ), Switzerland, Italy, Germany and Austria. The species is represented in the Czech Republic, Slovakia, southern Poland, northern Croatia and Hungary and the Carpathian Mountains in Romania and the Balkan mountains of Serbia and northern Albania. In the east, the distribution area of pulls on the Crimean southern Russia ( Karachay -Cherkessia ), the Caucasus region, Armenia to Central Asia ( Ili region, Kazakhstan, Issyk -Kul, Kyrgyzstan ). In the south it extends from Turkey to Iran. Bernd Schacht are China and Syria, but without literature documents.
The habitat of Euxoa birivia is very special and includes open habitats such as grasslands, rocky steppe, dry streams and rivers with grass cover, each with sandy- loamy soil in more mountainous regions. The few localities in Baden- Württemberg are between 500 and 800 meters above sea level. The site in Karachay-Cherkessia in Southern Russia lies at 1200 meters altitude. The lake of Issyk -kul in Kazakhstan is over 1600 meters altitude.
Way of life
Euxoa birivia is univoltine; that is, it is formed in only one generation. The moths fly from mid-July to late August. The moths fly in search of a suitable site often far and wide, are occasionally observed in deciduous forests, villages and cultivated land, so far away from their original habitat. They fly to the artificial light sources and come to the bait. The eggs are laid in small groups in sandy- loamy soil. These scrapes the female small depressions in the ground; after being laid the eggs are covered with soil. Although these observations are from the breeding, but they should also be true in nature. Very little is known about the food of the caterpillars. It is believed that they live on grass roots. In breeding the little caterpillars grouped ate also endive. After the Breeding observations they are nocturnal and very sensitive to light. In the last larval stage, the animals lived almost exclusively in the ground and came to the surface only at night to eat there or to take parts of plants in their transitions in the ground. Adults caterpillars also adopted dandelion. The species overwinters as a caterpillar probably in the egg. The observations are from the breed and must be supplemented by field observations. Given the wide distribution area, regional differences are conceivable.
Development
In breeding experiments on samples from East Tyrol, the little caterpillars grouped (L1 ) were developed in the finished egg after 14 days. Although temperature and humidity changes, which can trigger the hatching of Eiraupen other Euxoa species that Eiraupen not hatched in the fall. After a shortened winter rest of 150 days, the Eiraupen hatched in the spring. Development from the L1 stage to the L5 stage was only 30 days. The Vorpuppenphase to pupation lasted only 10 days. The pupal period until hatching of the moths lasted 26 days. The total duration of development was 230 days; However, this is the shortened by natural winter dormancy observed. Data are for " room temperature".
Endangering
In Germany Euxoa birivia is in the early warning. In Baden- Württemberg the species is extinct or lost.