Thorn spider
(Gasteracantha species)


Belongs to the family Gasteracanthinae. Also known as the jewel spider or the spiny spider. Female thorn spiders are 10 mm and males are 3 mm. They're white or yellow, with black spots and 6 spines on the edge of the abdomen. They have a hard, flat body. The legs are short and stout. 
These spiders often occur in colonies with multiple overlapping webs. Perhaps the colors and patterns of their dorsal surface mimic the color of food, such as flowers. It is also possible that the dorsal surface of the thorn spider is highly reflective in the ultraviolet part of the spectrum. Many flies and mosquitoes are attracted to bright light, and the kind of light rich in ultraviolet spectra, because these indicate the presence of field clearings adjacent to dense forests. Thorn spiders set their webs at an angle and that they sit on the underside of their webs with their backs to the ground. This suggests, that sun and nearby vegetation offer camouflage for the web. Daytime web-building and hunting, along with the web placement and orientation, is consistent with behavior that attracts prey traveling from darker areas to lighter ones.

These spiders lives in woodland edges, shrubby gardens, only in tropical or sub-tropical regions. They are harmless for people.