The funnel-web spider is similar in appearance to the wolf spider, but it is smaller and more delicate, with a body length of about ¼ inch. They live worldwide. They build webs in grass or leaf litter, on stones or in the corners of buildings.
To catch prey, it builds a sheet-like web with a distinct funnel shape leading to a retreat where the spider hides in the back. The sheet of the web acts as a catch basin for insects that blunder onto it, becoming stuck in the sticky silk. The spider, sensing the vibrations in the web, goes out to retrieve its meal. If the prey item is small enough, the spider will cut it out of the web and bring it down into its retreat to feed on.
Because these webs are often built in grasses, a common name for these arachnids is “grass spider.” Funnel-web spiders are active from March through October.
There are approximately 180 species of orb weavers in the world, coming in a variety of colors, shapes and sizes. Common traits include a rounded abdomen and orange-to-brown or yellow-black coloring. Legs of an orb weaver are generally very long, giving it a menacing look. Their overall body size can range from 6 mm for males and up to 10 – 20 mm for the females.
Habitats can range from grass to corners of homes or under protected porches. The spider sits in the middle of its web, head facing downwards, waiting for prey to come upon their net. If the spider is not found in the middle of the web, it is usually nearby monitoring the web by way of a “signal” line still attached to the spider. The moment a prey gets entangled in the sticky web, the spider can come out to finish the job. The web consists of radial strands, like spokes of a wheel, and concentric circles. Webs may be quite large, spanning several feet in width.
It is reported that orb weavers will re-spin a new web every night. Their proficiency at nighttime hunting makes them the ultimate garden bug security system.
So, instead of reaching for those environmentally harmful insecticides this spring, let a few itsy-bitsy spiders help you keep the insect population down.
Sources: Arizona-Sonora Desert Museum; insects.about.com