Hobbies And Interests
Things You'll Need
Instructions
Look for a web. The shape and size of the web will often give you clues about the species of spider you've found. Orb weavers spin large circular webs, while funnel web spiders construct large sheet webs on the ground with a funnel at one end. Others such as the trap door spider live in silk-lined burrows. Black widow spiders spin lacy, tangled webs. Wolf spiders and jumping spiders don't spin webs at all.
Place a clean, glass jar over the spider. Look at the shape of the thorax and abdomen. Use a hand lens or magnifying glass. Orb weavers have an oval shaped thorax and abdomen that resembles an hourglass. Cellar spiders have an abdomen that is longer than the thorax Crab spiders have a wide abdomen compared with the thorax. The common house spider has a large circular abdomen that looks like a bubble. Female spiders will have a larger, thicker and more developed abdomen than males.
Look at the arrangement of the eyes. The eyes are arranged in a set pattern around the head, which aids in field identification. Most spiders have eight simple eyes, while some species have six eyes. Crab spiders have six evenly spaced eyes; the two outermost ones are the largest. Orb weavers appear to have two vertical rows of eyes. Jumping spiders have two large front facing eyes that are larger than the remaining ones. Cellar spiders have eight eyes clumped together at the end of their heads making it difficult to distinguish between individual eyes. Line weaving spiders have two outer eyes on each side that angle toward the two front facing eyes.
Look at the color and markings on the thorax, abdomen and legs. Colors range from dull grays to browns and blacks to bright reds, yellows and greens. The common house spider has a brown thorax and/or abdomen with markings on its abdomen. Jumping spiders are reddish brown in color with no markings. Cellar spiders are light gray with brown markings on the thorax and a longitudinal stripe down the abdomen with horizontal stripes. Orb weavers are either orange or yellow red with other markings.
Take a picture. There are online forums where you can post a picture of the spider and request help in identifying it. You can also contact a nearby museum and ask to talk to the spider expert. Remember, though, it is very difficult to identify a spider by its description alone. It helps to have a picture to look at.