Ragno vespa - spider wasp

Description:

Classification: Araneomorphae; Family: Araneidae Common Names: wasp spider, zebra spider, spider wasp zebra spider, Argiope fasciata (common names indicate the main morphological characteristic of this spider, having the opistosoma varied).spider Argiope bruennichi is a very flashy looking, both plumage and size. The coloration of the abdomen is unmistakable in its black and yellow horizontal stripes: the picture as well as the intensity of color varies from item to item. The underside is dark brown, with two longitudinal yellow stripes arranged laterally. The cephalothorax is black and has a velvety appearance; legs, bristling black setae and sparse, they are amber with black anulature quite wide. Sexual dimorphism: females reach 2 cm and 5 cm of body and leg-span are significantly larger than males, reaching up to 1.2 cm in body and 3-cm leg span. The latter have a more slender abdomen and are devoid of color "marked", while the white-yellow typical of juveniles.

Habitat:

It is a spider that is well suited to a wide variety of environments. The only necessity is the presence of a more or less wide area where the spider can weave. It is found in many small pits (the cloth weaving from side to side) that bound both uncultivated and cultivated areas and in areas of very arid Mediterranean, near sandy beaches. In wooded areas, its presence near plants of Rubus fruticosus (wild blackberry), near the soil exploited for structural support of the web. or other plants, however, very low near the ground Aggressiveness: poor: if disturbed shall implement a defensive strategy very special staying at the center of the canvas, gives it a very rapid oscillatory motion, for a time that can vary from 15 to 30 seconds. If this tactic of "deterrence" has no effect chooses to escape while being nearby to threat ceased. In case of any bite, the effects of poison are mild, you feel the pain caused by the mechanical action of the chelicerae and un'arrossamento the interested party. The symptoms disappear within a few hours. Rapidity of growth: it is a spider seasonal from the very rapid growth. The young are born in late spring, and mature sexually in late August.

Notes:

ETHOLOGY Dissemination: the whole of Europe, excluding the northern part of Sweden and Norway. Habits: diurnal spider, lives at the center of its web, as opposed to what other araneidi with similar habits. As soon as a prey (mainly Orthoptera, or other flying insects also quite large) is trapped, the Argiope envelops emitting dies from a large amount of silk and, simultaneously, the bites several times. Then the victim is brought to the center of the canvas for food. During the night the spider will rebuild the damaged part of the web. Special features: the web of this spider has a unique zig-zag (stabilimentum said), arranged vertically, just below the center. The presence of this "embroidery", a real puzzle for scholars, many assumptions were made: one of the oldest claims that serve to make the fabric more stable. Other researchers have designed a simple excess material, or that it serves to make less visible the spider waiting for prey. A final hypothesis is that a system to make the web more visible to prevent birds and small mammals can destroy.