Spiny-backed Orb Weaver Spider, Key West Wanderings, Photos by Bill Klipp

All photos © Bill Klipp, not for Commercial Use of any type, for personal use only.


Gasteracantha cancriformis -- Spiny-backed Orb Weaver Spider

Spiny Orb-Weaver Spiders


The Spiny-backed Orb Weaver is a small harmless crablike spider with six characteristic spines along the back of its abdomen, they can come in a variety of colors. Orb Weavers are very docile, non-aggressive spiders that will flee at the first sign of a threat. They are not dangerous to people & pets, and are actually quite beneficial because they will catch and eat a lot of pest-type insects.

They are known for their nets, the spiral wheel-shaped webs that are so often spotted hanging from garden shrubs or between the branches of trees, meant for catching flying insects during the night hours. The webs often have little balls of silk that should apparently warn larger insects and birds from hitting and destroying the web. They eat many types of small bugs and insects that get caught up on their webs such as moths, flies, and even wasps. When an insect gets caught in the web the spider bite the prey, wrap it in silk, wait for it to die, then begin to eat. As a first step in eating, the spider will literally vomit digestive fluid over the prey then chew the prey with its jaws. The most commonly noticed Orb Weaver is female, since she sits on her web, feeding and eventually waiting for the much smaller males to find her to mate then she often eats the male after mating.
Orb weavers are known to live around the world with over 3,000 species mostly found in tall grass, short grass, shrubs, woodlands, and even in coastal areas. The native range of the Spiny-backed Orb Weaver is throughout the Southern United States, Central America and the Caribbean.