Spider of the Month -November 2019

This month’s spider of the month is Elize Vega Eveleigh’s Deinopis sp. (ogre-faced spider) that she found at Skukuza rest camp. These spiders are certainly interesting enough to be chosen as the spider of the month, and this brilliant stacked photo just adds to the reason we chose it. Elize used 12 photos to stack this image. She mentions that these spiders are difficult to spot because they do not have a web and look like sticks or dried seed.

The family Deinopidae (net-casting spiders or gladiator spiders) only contains two genera, namely the smaller-eyed Menneus spp., and the larger-eyed Deinopis spp., whose eyes are the largest of any arachnid. The word “Deinopis” originates from the Greek “deinos” (fearful) and “opis” (appearance).

These spiders are nocturnal and use their large posterior median eyes to spot prey in the dark. In fact, they see better in the dark than cats and owls. Since these spiders lack a reflective layer in their eyes, they create a light-sensitive membrane in their eyes when night falls. Since they don’t have irises, this membrane is destroyed when the sun rises.

They spin a little elastic “net” that they then cut loose and hold with their four front legs. In order to know how far they are from the ground, they will often measure the distance with their legs, and will often place fecal spots on the ground to help with aiming.

When they spot their prey, they stretch the net and catch the prey below. They have also been observed catching airborne insects like moths with the net, but they mostly focus on ground prey that are bigger and more nutritious, like crickets.