Spiny Orb Weaver

The spiny orb weaver, also widely known as the spinybacked orbweaver, is one of the most distinctive and easily identified spiders in warm regions of the Americas, thanks to its hardened, crab-shaped abdomen ringed with sharp projecting spines. Despite its formidable appearance, this species is a small web-builder that spends most of its time motionless at the center of a neatly constructed orb web.

Coloration varies considerably between individuals and populations, with abdomens commonly white, yellow, orange, or red, patterned with black spots, against which the spines and legs stand out sharply. This variability, combined with the animal's unusual shell-like body, has earned it the nickname "jewel spider" in some regions.

Widespread across the southern United States, Mexico, Central America, and the Caribbean, spiny orb weavers are common in gardens, citrus groves, and woodland edges, where their webs often catch small flying insects at head height along paths and garden borders.

• Hard, shield-like abdomen shaped like a wide crab shell, typically white, yellow, orange, or red with black spots
• Six prominent spines projecting from the edges of the abdomen, giving a spiky, armored look
• Small body overall, with the abdomen much wider than it is long
• Thin, relatively short legs compared to the broad body
• Distinguished from other spiny orb weavers by the specific spine arrangement and color pattern, though overall shape is unmistakable

This species builds webs in gardens, shrubs, citrus and other fruit trees, and forest edges throughout warm, humid regions including the southern United States (especially Florida and the Gulf Coast), Mexico, Central America, and the Caribbean. Webs are often strung between branches or garden plants at head height, frequently along paths, and can be conspicuous from late summer into fall when females reach full size.

Spiny orb weavers spin a classic wheel-shaped orb web, typically rebuilding or repairing it each day, and remain motionless at the hub waiting to detect vibrations from trapped insects. Diet consists of small flying insects such as gnats, flies, and moths caught in the sticky spiral threads. As with most orb weavers, males are much smaller than females and wander in search of a mate rather than maintaining a permanent web. The species plays a role in natural insect population control within gardens and orchards.

After mating, females produce one or more egg sacs, often attached to a leaf or twig near the web and covered with a fluffy silk layer, containing dozens to over a hundred eggs. Spiderlings hatch and disperse, sometimes ballooning on silk threads to new locations, then grow through several molts over the following months. In warm climates the species may produce more than one generation per year, while eggs or juveniles overwinter in cooler parts of its range.