Leggy

Female Opilio canestrinii

For several days in a row a couple of weeks ago, I found this female harvestman (harvestwoman?) sprawled out on a nettle leaf in the garden. Did she stay there the whole time, digesting a particularly big meal? Or had she made sorties and returned to a favoured spot? So many mysteries! She's an Opilio canestrinii, one of Britain's longer-legged harvestman species. The two rows of alternating dark and light bars on her back (see the picture above), her very long dark legs, and her white operculum (the little turret that her eyes sit in) help to identify her. Males are smaller-bodied, and more uniformly red-orange in colour. This is a newly-arrived species in Great Britain. First recorded in the Thames Valley in 1999, it has spread rapidly and is now found across England and Wales. In 2011, it was found in Scotland, and has since been spreading quickly from that initial location. Intriguingly, it wasn't known in Europe until the mid-1900s, when it was found in Italy; since then, its range has expanded to cover most of western Europe. In some places (i.e. the Netherlands), its arrival has led to the extinction of native Opilio species. Let's hope that doesn't happen here!