Adventures in Spider Misidentification: Bejewelled by a Shamrock

Fuzzy Cat-faced or Jewel Spider

Amazingly, not everyone likes spiders, but less surprisingly, those that fear spiders tend to react more strongly to the bigger ones than to the smaller ones. In Edmonton, one type of bigger spider that can startle both arachnophiles and arachnophobes is the orbweaver (Araneidae, Araneus spp.). Adult females can be large (bodies 1-2 cm long), stocky, and tend to be brightly coloured or boldly patterned and can be quite attractive, if confusingly variable. Arane is Latin for spider, so I think we can assume these spiders have been capturing peoples’ attention for a long time.

Cat-face apparent with a little imagination

For years, I assumed that all the large Araneus in my garden were the common Jewel Spider (Araneus gemmoides) aka Cat-faced Spider and even once posted one particularly nice picture as such. Alas, it turns out there are at least 8 species of Araneus in Alberta. Our putative Jewel Spider picture was not that, but of the Shamrock Orbweaver Araneus trifolium, another variable species.

Araneus trifolium Shamrock Orbweaver 

 No worries, we actually do have Cat-faced Spiders too and can now tell them from Shamrock Spiders. I suspect the 'shamrock' comes from the four pale spots with dark inner spots (which probably represent dorso-ventral muscle attachments) on the back of the abdomen. In any case, St Patrick's Day weekend seems an appropriate time to repost the picture with the correct name.

Shamrock takes a bit more imagination

So, the Home Bug Garden can boast of at least two species of Araneus, but are there more? Well, my friend John tells me there are about 30 species of Araneidae in Alberta and these are distributed across at least five genera other than Araneus. So, I think we can assume that the Adventures in Spider Misidentification series will have a long run.

Possible Furrow Orbweaver Larinioides sp.

So, here's a small, but interesting orb weaver that seems to be common in town and in the bush. I'm guessing that it is a Larinioides cornutus a Furrow Orbweaver (previously assigned to the genus Nuctenea). These spiders are reputed to overwinter as adults, at least in warmer parts of the world, so perhaps it is worth looking for them now.  

Larinioides cornutus anyone?