Linyphiidae

The Linyphiidae is the worlds second largest spider family encompassing 4552 species in 601 genera. The highest diversity is found in the northern temperate regions. In these regions as well as in the arctic regions spiders of this family dominates the spider fauna. The jumping spiders (Salticidae) is an even larger family but they generally require warmer conditions than the linyphiids and for this reason they are less well represented in the cooler regions. Linyphiids are found worldwide in all terrestrial biotopes and is perhaps the most widely distributed spider family. They range in size from very small to medium (1-8.5 mm body size). Most species are found at ground level but they occupy a very wide array of habitats. The members of the family build a sheet web sometimes dome shaped. The web has no retreat and the spider always hang inverted below the sheet. Larger species in particular sometimes add irregular vertical snares acting both as sheet suspension strands and barrage balloon wires impeding the flight of insects. When insects strike the vertical snares they fall down on the sheet and the spider rush to bite the prey through the sheet web. Many species disperse by air and the phenomenon of ballooning is very noticeable in this family when very dense populations try to balloon at the same time. The spiders climb up high in the vegetation and point the spinners toward the sky. In this position they let out some strands of silk and eventually the wind will lift the spiders up in the air. Often they only manage to fly a short distance but they will keep trying sometimes resulting in a layer of shimmering silk covering the vegetation. Ballooning takes place usually in late summer. Ballooning may result in spiders literally raining from the sky.