Nigma walckenaeri
Nigma walckenaeri (females )
Nigma walckenaeri is a spider from the family of Kräuselspinnen ( Dictynidae ). The species is distinctive by their green coloration in Central Europe.
Features
Nigma walckenaeri reaches a body length of 3.5 to 5 mm, it is the largest species of the family in Central Europe. The front body ( prosoma ) is monochromatic light green to greenish beige in females. It shows a light hair formed by U-shaped drawing, which opens to the front.
The rear body ( opisthosoma ) is mostly monochrome bright light green, but can also carry a whitish or yellow spot drawing. It shows especially on the sides in a narrow bands arranged, white hair. The legs are also solid color green.
In the male, the head region is significantly increased. Furthermore, prosoma and legs yellow-brown.
Distribution and habitat
The thermophile species inhabited a relatively small area in the south-western Palearctic from Britain and Portugal east to Iraq from Germany and south to North Africa. The type is missing in Ireland, Scandinavia and the Baltics. The distribution area includes the temperate to subtropical zone. In Germany the species is limited to heat- favored areas as well as urban areas and missing in the northwest.
The species inhabited in southern sunny forest edges, in Germany it is however to be found almost exclusively in the settlement area. They settled here, especially with ivy or Virginia creeper clad house walls, rarely, large-leaved shrubs such as lilacs.
Way of life
Nigma walckenaeri building a tent-shaped, translucent living tissue on top of larger leaves, the sides are curved upwards. The network is usually located at the leaf base and opens downward. The spider is there very well camouflaged because of their coloring. From the opening catch threads are created on the leaf blade, where also quite large insects such as medium-sized fly caught in a zigzag shape.
Sexually mature animals occur from August to October, on buildings, they can be found even in December. Copulation, the female grasps the chelicerae of the male, which then alternately inserting his pedipalps into the genital opening ( epigynum ) of the female. The lens-shaped egg sac is created hidden in the vegetation.
Endangering
The species is rare in Germany. Overall, a hazard is assumed, however, dispense with a classification in a hazard category. In Brandenburg and Berlin, she is frequently in suitable habitats and is considered safely.