Fir extensor foot
| Fir extensor foot | ||||||||||||
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Fir extensor foot ( Calliteara abietis ) ♂ |
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| Calliteara abietis | ||||||||||||
| ( Denis & Schiffermüller , 1775) |
The fir extensor foot ( Calliteara abietis ) is a butterfly (moth) from the subfamily of the bearer moth in the family of Erebidae.
features
The males have a wingspan of about 40 mm and are brown or gray in color. They have clearly combed antennae. The females are usually somewhat larger with wingspans around 50 mm, from more white to light gray basic color and have rather thread-shaped, very weakly combed antennae. In both sexes, the drawing of the forewing upper side consists of strongly jagged, dark transverse lines. The inner transverse line in the basal area and the outer transverse line in the disc area are particularly prominent. The middle field is also traversed by a dark, relatively blurred, dark band. Especially in the males, a light line parallel to the costa stands out due to the darker basic color between this band and the inner transverse line. Occasionally this line is expanded to a lightened basal field. The wavy line in the post-disc area is usually indicated as a light line between the darker basic color. The wing edge is piebald. The formation of the transverse lines and the basic color are variable. Sometimes the transverse lines are broken up into individual sections and not continuous. The basic color can range from almost dark gray or brown to light and almost white. The most striking and most constant feature is the v-shaped kidney blemish, which clearly distinguishes the species from the related beech extensor foot ( Calliteara pudibunda ). This is also usually drawn with less contrast and tends to have very blurred, less jagged transverse lines.
The fully grown caterpillars have a green base color. They have two white vertical stripes on their backs, and another slightly below the light stigmas. These longitudinal stripes are often interrupted in the middle of the segments. The individual sections of the white stripes are outlined in black lengthways. The entire caterpillar is covered with long, but not very thick, black hairs. Similar to the beech extensor foot, the caterpillar has dorsal tufts of hair from the fourth to the seventh segment, which are reddish brown. The tufts of hair are usually whitish on the sides and can also have darker areas in the middle. On the side of the head capsule, two long, black hairbrushes protrude forward and on the last segment the caterpillars carry another yellowish, upwardly protruding hairbrush.
Similar types:
- Beech extensor foot ( Calliteara pudibunda ), ( Linnaeus , 1758)
distribution and habitat
The fir extensor is a type of boreal coniferous forests and reaches the western limit of its range in Central Europe . In Central Europe it mainly inhabits spruce and fir forests in the low mountain ranges .
The westernmost part of the distribution area is in Germany and Denmark . From there, the species occurs eastward in Poland , the Czech Republic , Austria , Hungary , Romania and Slovakia . In the north the Baltic States , Sweden , Norway and Finland are settled. The largest part of the distribution area extends over western Russia , the Urals and Siberia .
Way of life
The flight time begins in most of the distribution area at the beginning of June and ends at the end of July, rarely in August. However, the main flight time is in July. In the northernmost parts of the distribution area, the flight time can be postponed by a few weeks. In rare cases, there may be a partial second generation in September.
The main fodder plant in Central Europe is the Norway spruce ( Picea abies ), more rarely the silver fir ( Abies alba ). In the northeastern part of the distribution area, the Siberian larch ( Larix sibirica ) is mainly used. In addition, the common juniper ( Juniperis communis ) is given as a fodder plant and in parts of Siberia caterpillars have been found on Scots pine ( Pinus sylvestris ). Presumably the caterpillars live on a wider range of conifers. The moths lay the eggs in large groups of around 60 eggs in the treetops on needles, bark and sometimes in cracks in the bark. Females seldom lay their entire egg supply, an average of 180 eggs, at once. The caterpillars overwinter in the 3rd or 4th instar and go to the ground for this. If the temperatures drop below 6 ° C in autumn, the caterpillars look for their wintering spots on the forest floor and do not leave them until the end of April to May. In the treetops, the caterpillars grow quickly in spring, depending on the weather, and are fully grown around the end of May to the beginning of June. The pupation takes place in a loose web of caterpillars silk and braided hair of the stick instead. The cocoon is usually attached to needles or bark.
Harmful effect
Although the extensor tree lives on economically important conifers, it is usually found in its habitats in too low densities to be harmful. From the entire distribution area it is only known in Eastern Siberia that serious damage to the coniferous tree population can occur through mass reproduction. Mass increases have been observed in forest areas in Buryatia , Irkutsk , the Krasnoryarsk region , Transbaikalia , and Sakhalin . These mass increases can extend over more than 100 square kilometers and seem to occur periodically at intervals of about 10 years.
Individual evidence
- ^ A b c d Axel Steiner, Ulrich Ratzel, Morten Top-Jensen, Michael Fibiger: Die Nachtfalter Deutschlands . Bugbook Publishing, 2014, ISBN 978-3-00-043862-2 , pp. 389 .
- ↑ Calliteara abietis in Fauna Europaea. Retrieved September 25, 2018 .
- ↑ a b c d Yu. I. Gninenko, GV Serdyukovb: The Coniferous Tussock Moth (Calliteara abietis, Lepidoptera, Lymantriidae) in Buryatia . In: Entomological Review . tape 90 , no. 8 , 2010, ISSN 0013-8738 , p. 999-1002 , doi : 10.1134 / S001387381008004X .
- ↑ Calliteara abietis in the Lepiforum. Lepiforum, accessed September 25, 2018 .
Web links
- Calliteara abietis at Fauna Europaea. Retrieved September 17, 2013
- Lepiforum