Wednesday, October 21, 2020

Shiny Wolf Spider

Mark Bower sent me this photograph of a spider carrying babies on her dorsal abdomen. The only spiders that do that to my knowledge were wolf spiders and I couldn't find a black shiny wolf spider in any of our books. I sent the photo off to experts and got this response from David Bruns from MDC at Powder Valley Conservation Nature Center.

"Female wolf spiders are the only spiders I know of that carry their young on their abdomen.  More than 40 species of wolf spider have been documented in Missouri. They are an incredibly important group of spiders because of their abundance, particularly in forests, where they eat countless insects that can damage trees and plants.  They are considered harmless, meaning that they do not have venom that is medically significant to humans."

The photo is of a female Allocosa sublata. This species is recognized by its medium size, (as spiders go), the shiny black carapace, and dark rings that can be discerned on the tibias of the legs. This is an uncommon species in Missouri and the photo is extraordinary since it captured one with spiderlings which remain with the mother for only a few days. The mother does not provide direct care to the young, but provides protection from predators (particularly other wolf spiders) and serves as a mechanism to disperse the young. These will overwinter in the leaf litter as young spiders.

Allocosa sublata - David Bruns

You can compare David Bruns' photograph above with this full description in  Bugguide.

""Carapace dark red brown to black, sometimes iridescent, darker at margins, with few setae. Sternum orange brown. Chelicerae dark red or red brown. Legs dark orange or red brown, sparsely covered with setae; femora and tibiae each with 2 indistinct, dark rings. Abdominal dorsum dull red, densely reticulated with black."