Eriophora fuliginea
Eriophora fuliginea

Eriophora fuliginea

Photo by Rosannette Quesada-Hidalgo

Eriophora fuliginea is a beautiful orb-weaving spider that belongs to the family Araneae. It is brown with a noticeable coat of thick short hairs. However, individuals vary in coloration: some have a straight white line on the dorsal part of the abdomen, some a set of small white spots or a big white spot like the one in the picture, and some have no white at all. The undersides of the femurs are usually bright red, but they can also be yellow. Males and females are similar in coloration, with males being somewhat smaller than females.

These spiders are nocturnal. During the day, they can usually be found in the vegetation in a resting position, in which they press their legs against their body, keeping the bright color on their undersides hidden presumably to remain camouflaged. They can also be found inside a retreat they build by fastening leaves together with silk. Daily, usually just after sunset, the spider builds a large vertical orb web to intercept flying insects. The lines in the webs are very strong and the webs can span about 80 cm, and they sometimes catch larger animals. There is even one report in Panama of an individual of this species feeding on a small bat trapped in its orb! Every day before dawn, these spiders will eat their web and hide in the vegetation or inside their retreat for the day. The retreat is frequently located at the end of one of the upper frames of the orb web, and they can use the same one for several days.

Even though these spiders are fast and voracious predators, they are thought to be harmless to humans, and their venom is not considered to be of medical importance. This species is found only in the Americas, from Guatemala to Brazil.