The July Spider of the Month (SOTM) is this velvet spider (Eresidae), photographed by Cecile Roux in Kasteelberg, Western Cape.
I’m not sure if this is a tree velvet spider (Gandanameno sp.) or a ground velvet spider (Dresserus sp.). Since Cecile found it under the bark of a log, it’s probably the former. It’s usually easier to distinguish the two from adult males, since Dresserus males have horn-like tubercles on the front of the carapace.
These spiders are fairly slow. They are often found under rocks and logs, under bark on trees, in rock crevices, etc., where they spin a mesh web and hide in a retreat nearby. The webs are signal webs, whose purpose is to signal to the spider that prey is nearby, instead of trapping the prey in the silk.
Their bodies are covered in very fine, velvety setae, giving rise to their common name. I don’t know the Latin/Greek origin of the words Gandanameno or Dresserus, and the family name Eresidae is likely named after the Greek island of Eresus (not sure why). There are 23 Dresserus species in the world, 11 of which occur in South Africa, and five Gandanameno species, three of which have been recorded in South Africa. The habitat and behaviour of the velvet spiders differ vastly between genera. Some, like the buck spoor spiders (Seothyra spp.) live under sand in a burrow and spin a signal web that resembles a buck spoor, while some Stegodyphus species live in a community nest comprising almost entirely females. Of 182 people who voted, this photo received 105 (58%) votes. It is only three votes more than the runner-up (Rion Lerm’s Portia schultzi). This is Cecile’s third SOTM. Congratulations, and please keep posting!