Thera vetustata

White fir softwood tensioner ( Thera vetustata )

The white fir softwood tensioner ( Thera vetustata ), formerly known as Thera stragulata and sometimes referred to as Bright spruce forest - blade tensioner or mountain spruce forest - blade tensioner, is a butterfly (moth ) from the family of the tensioner ( Geometridae ).

• 6.1 Notes and references
• 6.2 Literature

Features

Butterfly

The wingspan of the butterfly is 24 to 30 millimeters. The ground color of the forewing is mostly milky white, sometimes white or gray yellow gray. The root zone is colored light brown to black-brown. With the same color, a large spot stresses near the center of the front edge. The intensity and refinement of this spot is variable. In the lower middle or at the rear edge of little black specks are present in some specimens. However, the dark center field area is almost never consistently dark, which differ in the moths of other therapy types. Also dark, the apex region emphasizes. In a thin seam band, interrupted blackish line, which continues to the whitish hind wings runs. This show also weak -scale cross lines.

Caterpillar

Adults caterpillars are green and have whitish lines and stripes, which is why they are protected because of the similarity thus achieved with white pine needles optically well from predators.

Geographical distribution and occurrence

The distribution area of silver fir softwood tensioner extends from Spain to Central Europe to the Balkans. The species is absent in Fennoscandia. In the Alps, it still occurs at an altitude of 1600 meters. The animals prefer to inhabit pine and mixed forests.

Way of life

The nocturnal moths fly in two generations, from late May to mid-July and from mid-August to mid-September. During the day they can be sometimes observed sitting on tree trunks. At night they visit and artificial light sources. The caterpillars feed on the needles of the silver fir (Abies alba). It remains to be studied whether they accept additional fodder crops. The caterpillars overwinter.

Endangering

The white fir softwood tensioner comes in Germany in different numbers before missing in the northern regions and is listed in the Red List of endangered species on the early warning list.

System

The species was earlier than individual form of the variables softwood stretcher ( Thera variata ) is considered, which is why it is often referred to in older records as formatted or aberratio stragulata.

Swell