Identify a Cobweb Spider
Cobweb spiders (Theridiidae) are commonly found in and around your home and the majority of them are harmless. Their webs are messy and resemble the type of Halloween decoration webs you find in stores.
Contents
Steps
- Know what a cobweb spider is. Here are some key characteristics.
- Physical features: Bulbous black body, never more than 1/2“ (12 mm) long.
- Poisonous: No.
- Lives in: in North America, southern Russia, New Zealand, and Europe
- Eats: This spider preys on various kinds insects like pillbugs, ticks, flies, mosquitoes and ants. They will also eat spiders that are poisonous to humans, such as the Identify-a-Hobo-Spider.
Identifying a Cobweb Spider
The Cobweb spider is very dark brown to black and has no easily identifiable markings.
- Look at the abdomen. It is sometimes almost a glossy black and sometimes there are very pale, greenish-brown markings on the abdomen.
- Observe the legs; they will be black and spindly with no visible markings.
Recognizing Cobweb Spider Habitats
This spider is prolific in many regions of the world, especially in North America and Europe. It builds a sticky silk cobweb that looks tangled and erratic.
- Look for messy webs in the corners of your house, cellar, garage or outdoor sheds. The webs are irregular in shape and quite sticky.
- Be aware that this spider is almost always found in dark places, including caves.
Treating a Bite
The Cobweb spider is neither aggressive nor poisonous. Most don’t even have teeth, but in the event you are bitten by a cobweb spider, apply general first-aid.
- Wash the area of the bite with soap and water.
- Apply a paste of baking soda and water to relieve itching or soreness.
Tips
- Cobweb spiders typically live for 1 to 3 years, and are preyed on by wasps and Pirate spiders.
- Because Cobweb spiders are black, they are sometimes mistaken for Identify-a-Black-Widow-Spider, which are also a type of cobweb spider, but common Cobweb spiders do not have the orange-red hourglass pattern on their abdomens that is indicative of a Black Widow spider. (However, note that the hourglass pattern is not always evident.)
Warnings
- This species of spider has very poor eyesight; the Cobweb spider detects vibrations in or near its web. If you should walk into a web, it is possible, but very unlikely, the spider will bite you because most of these spiders have no or very few teeth.
Sources and Citations
- http://www.uky.edu/Ag/CritterFiles/casefile/spiders/cobweb/cobweb.htm
- Herbert and Lorna Levi, Spiders and Their Kin, (New York, NY; St. Martin’s Press 2002)
- Lorus and Margery Milne, Audubon Society Field Guide to North American Insects & Spiders, (New York, NY: Alfred A. Knopf, Inc. 1980)
