Thursday, September 22, 2011

Spiders in the Mist

Spider Web
My partner caught this picture of a dew-y spider web as the fog lifted Wednesday morning, 9/21/11.  The web's shape indicates its spinner is one of the approximately 2500 species of spiders in the family Araneidae who create the characteristic circular web seen here.  From the Ohio State University Fact Sheet:
Orb weaver spiders construct the familiar circular, flat, elaborate web in which flying insects are trapped. Each species of orb weaver typically constructs a web with a distinctive design. Webs usually occur outdoors. These spiders have poor vision and locate their prey by feeling the vibration and tension of the threads in their web. They use silk to wrap the victim.

Many species of orb weaver spiders are large (approximately 1 inch), but others are quite small (approximately 0.1 inch). Some have oddly shaped abdomens (pointed spurs, conical tubercles, etc.). Some are very brightly colored. One common spider, known as the yellow garden spider (Argiope aurantia), has silver hairs on the back of the cephalothorax and a large abdomen marked in black and bright yellow or orange. This spider is about 1 inch long and hangs head down in the center of the web, which is found in brambles, bushes, tall grasses, etc. in open sunny places.

Despite their formidable appearance, orb weaver spiders are not considered dangerous. Some species can bite if handled.
The University of Illinois adds, "The orb weaver produces an oil in its mouth and spreads this oil on the body, preventing it from sticking to its own web. They paralyze their prey with venom and then crush it with their pedipalps (a set of mouthparts.) Once the prey is crushed, the liquids in its body are consumed. Spiders mate by males spinning small webs that they place sperm in, and then transfer the webs to the female."

Previous encounters with these beneficial arthropods can be found here and here.


  1. Why are there so many spiders around this year? I can hardly walk out of my house without walking into a spider web.

  2. I'm not aware of any local spider census taking, or studies, that could verify one way or the other that there are more spiders around this year, over previous years. One spider expert, however, has this to say:

    "It's also at that time (late summer) that people ask me "why are there so many more spiders this year than usual," something I've heard every year for the past 30 years!"

    More here:

    It's certainly possible that there are more spiders around this year, but absent objective data, there is no way to tell. You may also just be noticing something that was missed in years' past. 2011 environmental conditions (a long, hot, dry spell mid summer in our area) would, in general, act against increased spider populations, but favor butterflies, moths, and grasshoppers, as best as I understand it.