Cross Orb-Weaver Spider

Cross Orb-Weaver Spider   (Araneus diadematus)

Common names; European Garden Spider, Cross Spider, Diadem Spider, Crowned Orb-weaver, Garden Spider, Garden Cross Spider.

Habitat

Found usually next to buildings with exterior lighting, tree branches, tall grass, weeds, fences, walls and bushes. Araneus diadematus is most often sighted outdoors, and during the month of October. Orb weavers construct organized, circular grid webs that are similar in shape to webs depicted in Halloween decorations. More specifically, orb weaver webs are made of radial strands of silk that look like the spokes of a wheel with the spokes connected by numerous concentric circular silk strands.

Food

Orb weavers are typically nocturnal spiders and many species will build or do repair work on their webs at night. They are not hunters or wanderers, they will sit in their web or perhaps move off their web and wait for prey to get tangled in their web. Small insects such as flies, moths, beetles, wasps and mosquitoes are examples of insects that make up the spider’s diet. Some of the larger orb weavers may also trap and eat small frogs and humming birds should they venture into the web. 

Biology

Adult females range in length from 6.5 to 20 millimeters, and the males are 5.5 to 13 millimeters long. The color varies greatly from specimen to specimen. Generally, the smaller and/or younger individuals are darker while the adult females are lighter. The background color is yellow to brown with two longitudinal, wavy or scalloped lines (folium). There are several white or yellow spots within and around the folium. Four elongated spots appear toward the anterior end of the abdomen, creating what appears to be a cross. As with the previous species, the carapace has three dark, longitudinal lines or bands. The adults are found from late summer through autumn. In late September, the females leave their webs and seek out protected locations to deposit between 300 to 900 eggs. The eggs are enclosed within a cocoon of yellow, silken threads, shaped in a hemisphere. Typical egg deposition sites include under the bark of dead trees and in cracks and crevices.

Threat

A recent report of verified spider bites lists this spider as producing a range of symptoms, including pain, swelling, and redness. Systemic reactions included anxiety, nausea, headache, and muscle cramps, but not all individuals had the same reactions. Duration of symptoms/reactions ranged from 2 days to 3 weeks.

Prevention

Some key preventive things a homeowner can do is reduce the population of insects that serve as food for spiders, seal up holes, cracks and gaps in the home’s exterior to prevent entrance by spiders into the home’s living spaces and remove ground litter, such as firewood stacks, that serve as spider harborage.