Spiny-backed Orb Weaver Spider

Description:

Females are 5–9 millimetres (0.20–0.35 in) long and 10–13 mm (0.39–0.51 in) wide. The six abdominal spine-like projections on the abdomen are characteristic. The carapace, legs and underside are black with white spots under the abdomen. Variations occur in the colour of the upperside of the abdomen with black spots on white to yellow ground colour and red spines or yellow instead of white. Spines are sometimes black. Like in many other spiders, males are much smaller (2 to 3 mm long) and longer than wide. They are similar to the females in colour but have a gray abdomen with white spots and the spines are reduced to four or five stubby projections.

Habitat:

Tropical dry forest of NW Costa Rica 7 weeks into the 6 month dry season.