Common House Spider
This one was from under the windowsill on October 23, 2022. I am pretty sure it is a Common (or American) House Spider, Parasteatoda tepidariorum. I don’t think it is mature, though, because it was smaller than the common house spiders that I’ve seen before. In particular, it does not have an enormous bulging abdomen like a female would, or big pedipalps like a male would.
It does have the highly-reflective posterior median eyes that reflect my camera flash like spotlights, similar to the Steatoda spider that I posted a couple of weeks ago on January 1. Here is a closer shot of the eyes:
One of the issues with cobweb weaver spiders like this is that they rest all scrunched up with their legs obscuring their bodies, and when they are unscrunched they are usually moving along pretty briskly. This makes it hard to get good, unobscured, non-blurry shots of their bodies. These were about the best I could do.
Anyway, these spiders are the ones that commonly make fairly messy, random-looking cobwebs in corners, under furniture, and in general out-of-the-way crevices around the house. They are also common outdoors in North America, which is in fact where they are native to. I think they normally lived in places like rocky cliffs, under logs, and in other somewhat-protected places outdoors until they found out that our houses suited them very well also. At this point, they are found in human habitations all around the world, making them one of the cosmopolitan species that came from North America rather than being brought here.
And, as is the case with almost all spiders in the house, they are absolutely not dangerous to humans. If anything, they eat things like gnats and dust mites and cockroach nymphs that get into the house. As long as one doesn’t mind the webs accumulating, they are absolutely nothing to worry about. The adult females can live for a couple of years, and will produce up to four or five egg-cases that look kind of like little balls of brown paper.
Comments are closed.
I sometimes wonder how these guys can compete with the spiders that spin more sophisticated webs. I suppose that a cobweb sort of thing takes less time and energy that a big orb and probably attracts fewer predators.
I think the answer is that they aren’t actually competing, they are hunting different things. The orb-web weavers are trying to catch insects on the wing, like flies and moths. The cobweb weavers are trying to catch things that are trying to hide in corners and crevices, like springtails and roaches. There are others that spin flat webs to catch insects taking off from the surface of the water, like mayflies and mosquitos. And still others make the “sheet and funnel” type webs to catch insects that are strolling along the surface or dropping down from above, like ants and grasshoppers. And then there are the ones that just make hidey-holes so that they can pounce on unwary passers-by. These are all independent niches, not direct competitors.
I should do a posting comparing the various styles of spider webs, and what sorts of prey each one is targeting.
I didn’t think of that. Way cool!