Montana Arachnids (Spiders and Allies) - Part 1 (Spiders)

[hengruh]

I put together some info on insects in Montana a few posts ago, so now I am tackling spiders and other arachnids. As with insects, there is no comprehensive source on Montana spiders, so I had to collate materials from the internet and books. The sources are found at the bottom of this post.

Following are some of the most common types of spiders

Comments

Re: Hobo Spiders and Aggressive House Spiders

[hengruh]

That site is in error unfortunately. it just paraphrases the information on the Hobo Spider entry in Wikipedia and makes a few errors in the process.

The webpage says: "Hobo spiders (Tegenaria Agrestis) were introduced into north-western USA1 from Europe by commercial vessels carrying agricultural products. They were probably introduced during the early 1900 to the port of Seattle, and have since then spread to the states surrounding Washington, which is Oregon, Idaho and Nevada, Montana and Utah."

But it also says:

"Lesser house spider or common house spider
Both named are used to describe Tegenaria Agrestis, a close sibling to the Hobo spider. In contrast to its venomous cousin, the house spider is not venomous. It is found throughout most of the US and Europe. It is very difficult to discriminate between this spider and the hobo spider as their size is approximately the same and they have the same chevron pattern on their abdomens."

So it is saying that the Hobo Spider is Tegenaria agrestis (btw the species name is not supposed to be capitalized) and the Lesser house spider/common house spider is also Tegenaria agrestis...but they are not the same spider, just "close siblings."

So which is it? If they are different species, they cannot have the same scientific name, right? That is the purpose of having scientific names, because common names can be misleading and used for entirely different species.

Check this site out instead: http://bugguide.net/node/view/31446
The Hobo spider (Tegenaria agrestis) is the one with dangerous venom. Its name agrestis is mistakenly thought to mean aggressive, but it means "of the field."

The lesser or common house spider, which some mistake for the hobo spider, is Tegenaria domestica (aka Barn funnel weaver) (http://bugguide.net/node/view/31445). The other relative sometimes mistaken for a hobo spider is the giant house spider (Tegenaria gigantea) (http://bugguide.net/node/view/31449)

I know there are hobo spiders in Ronan, and in Helena. I don't know how far east they have gotten in Montana. I think eastern Montana may be too dry for them, but I guess we'll see :-)

Re: Hobo Spiders and Aggressive House Spiders

[ext_2075893]

Ok i didnt know how to ask a question on here so im using thisi have a spider actually numerous that i dont know what they are a dark brown almost black shiney shaped like a widow but smaller they have white dots on tummy havent seen any hourglass but they hang togeathern i dont like it because its usually on my childrens strollers n outside toys no matter where i put them they appear there again which is widow behavior as communitys can u help me figureout what it is

Re: Hobo Spiders and Aggressive House Spiders

[hengruh]

DO they look like this when they are hanging together? http://en.wikipedia.org/wiki/File:Patas_20100626.jpg

If so, they are: http://en.wikipedia.org/wiki/Opiliones