Labyrinth Spider
Metepeira arizonica

Family: Araneidae

Description

The web of this spider is more easily recognizable than its body. The labyrinth spider most commonly constructs its web between the pads of prickly pear cactus. It builds an orb web, behind which is a tangled, disordered web made with some debris woven into the silk. Below the debris is a silken retreat in which the spider hides. The spider is small, about ¼-inch (12 mm) long, with a bulbous abdomen and thin delicate legs. The carapace is brown or grey; the abdomen is dark with a distinct white pattern.

Distribution

This spider is found in Arizona and California.

Ecology

Like many other spiders, the labyrinth spider is a predator that uses the orb portion of its web to ensnare prey. It is a passive hunter that lets the web do the work. Small insects that visit the prickly pear cactus to drink nectar or eat the fruits sometimes inadvertently fly into the labyrinth spider’s web.

Life History

The labyrinth spider is active, with its webs visible in prickly pears, from March through October. During the rainy season the female mates and lays eggs. She builds an egg case around the eggs and hangs it in her web near her retreat where it is camouflaged by other debris in her web. Once the young emerge they are self-sufficient; they disperse by ballooning.