PIRATE SPIDER RAIDS
A SUFFOLK GARDEN

The Pirate Spiders of the family Mimetidae are so called because, despite their small size, they raid the webs of other spiders. However, these raiders are not out to plunder the larder of the web’s owner, they are after a much bigger prize, the web owner itself. By plucking at the strands of the web, the Pirate Spider lures out the web owner and then rapidly paralyses it with a quick bite. Once subdued the web spider is then sucked dry through a small hole in a leg.
Four species of Pirate Spider, all in the genus Ero, occur in Britain and three of these have been found in Suffolk. They are small (2-3mm) but distinctly patterned spiders with one or two pairs of tubercules protruding from their globular abdomen and a series of long, curved spines on the front two pairs of legs. The two most common species, E. cambridgei and E. furcata, are quite widespread in the county and can be found at any height on the vegetation in almost any habitat. However, they do not occur in large numbers and are often overlooked due to their small size. The third species, E. tuberculata, is usually associated with heathland and only occurs in southern England south of a line from the Severn to the Wash. Even within this region it is considered uncommon and has been given a nationally scarce status. In Suffolk, E. tuberculata has been collected previously from Flatford, Hollesley and Walberswick but not during the last twenty years. In October 2005 a single female specimen of E. tuberculata was found on honeysuckle covering a fence in my Tattingstone garden; not a typical habitat for the species but it is known to occur away from heathland and has previously been reported from gardens. The presence of four tubercules on the abdomen, their arrangement (the rear pair widely separated so it almost appears all four are in a single line) and the contrasting pale colour of the abdomen behind the tubercules combine to characterise E. tuberculata. This species is normally found as an adult in the late summer and autumn and the other pirate spiders can be found from the spring through to the autumn so now is the time to start looking for these brave buccaneers of the spider world (or dangerous cannibals depending on your point of view). Get out your hand lens and start checking for those bumpy abdomens and spiny legs and let me know what you find.