Money Spider species Erigoninae sp
The Americans call this subfamily of the Sheet-web Spiders Dwarf Spiders. And like this name indicates they are all very small indeed. Very few are up to 6 millimeters long, most are some 1 to 3 millimeters long and a few are even less than 1 millimeter in length. In Britain these spiders are referred to as Money Spiders. All Money Spiders are very similar: most are shiny, black or brownish and without markings on thorax or abdomen. And thus this is a very difficult group when it comes to identification: you really need a very good magnifying glass or sometimes even a small microscope. By some the whole group is considered to be just a subfamily of the Sheet Web Spiders, in which case the name Erigoninae is used. In Western Europe there are hundreds of species.
These spiders can travel great distances. But being so small, how do they do that? The answer is 'ballooning'. When conditions are good, they produce a wire, which is flowing free in the air. When the wire is long enough, the wind will left it, with the spider still dangling on the other end. Later they will drop back to earth. Ballooning spiders can travel well over 100 miles! Small spiderlings of bigger species use the same method to conquer new territories.
