Saturday, November 27, 2010

Spider Byte

The blue mud dauber may be a bit of a blackguard in one sense, but in another she is something of a heroine. Two workers at the Louisiana State University Medical Center found that blue mud daubers take reat numbers of black widow spiders. .. They found nearly one hundred black widows in five nests.
        from Wasp Farm by Howard Ensign Evans

Thursday, November 25, 2010

A Spider's Thanksgiving

The Fence Spider is having a good Thanksgiving this year. Usually, when I see her with prey, it's fruit flies. Yesterday, she caught something much bigger with antennae that are hanging out of the knothole. I can't get a really good look, but I think it's a cricket.

Bon Appetit, my dear Agelenidae.

Saturday, November 20, 2010

Steatoda Grossa: False Black Widow (2)

We're running across more and more Steatoda grossa in the house these days. There were the spiderlings in the kitchen, the one in the bathtub, another under the sink, and one under a backpack this morning. The three yellow lines on the abdomen (You can see them in this picture, if you look) are very helpful in identifying them.

I've been catching them--easy to do, just stick a jar over them, wait til they web to the bottom, turn it over, and put the lid on--and taking them outside to release them. They are not particularly venomous to humans, though reportedly their bites do hurt, and they eat black widows. I figure everyone will be happy with them outside. I read in one photographer's blog that putting them in the fridge for a while might slow them down long enough for photographs, and I thought I'd try it and see if I could get some ventral views, but I didn't want to hurt the spider, so I guess I didn't leave it in long enough: He took off as soon as the jar was turned over outside. This is one of two pictures I snapped as he dashed toward the nearest plant and hid himself under the saucer. I'm going to try to see if I can spot him near the rim of the saucer tonight, but I bet I won't. The Steatodas seem to be very light-sensitive and hide when I get near with the light.

Thursday, November 18, 2010

Fence Spider 2

 The Fence Spider is still at home and happy in her knothole. She really spins fairly elaborate sheet webs, spanning ten to twelve inches of the bar there, but they get broken every time anyone opens the door. She's not at all shy and will come out to investigate when I take photos.

Her position is an excellent one for catching fruit flies; I've seen her with up to three in the web. Unfortunately, I've never seen her at web-mending, so I do not know at what point she decides to jettison her prey.  I think she may be in the Agelenopsis family, but I am not entirely sure how to tell the difference between an Agelenopsis and a Hololena. I'm going by the leg stripes, at this point.

In any case, I'm still very impressed by the way she makes use of the existing structure of the fence for her funnel. 

Saturday, November 13, 2010

Spider Byte

"Hypothetical calculations suggest that the spiders living on 1 hectare (2½ acres) of land devour over 47,500 kilograms (104,500 pounds) of prey each year, most of which is insects and other spiders."
          from The World of the Spider by Adrienne Mason

Black Widow Spiderlings

The other day, I went for a walk at Bolsa Chica, and I found this tiny spider living in under a curled up piece of bark. It was a pretty little thing, all marbled brown and white. I could tell it was a Theriid, and was pretty happy with myself for that, but otherwise, I had no idea.

Turns out it's a widow spiderling. Baby black widows really aren't black. Looking at the pictures up here, on bugguide, it looks like male black widows aren't always, either.

And looking at my own pictures, I'm no longer sure whether Milady is a black widow or a brown. This identification business is confusing.
Oh, and someone gave me a link to a site on black widows and the way to tell the difference between widows and steatoda. I'm still figuring it out. Anyway, the site is here. Since it seems all of the Theriids hurt when they bite, and it's generally a good idea anyway, my policy is "look but don't touch," for all spiders.

Friday, November 12, 2010

Steatoda Grossa: False Black Widow

 So, I'm learning that there are things that look like Black Widows but aren't.  They are all in the same family,Theridiidae, and all have the same hunched up body shape, but they are not all widows. They do, by all accounts, have a painful bite, just not up to widow standards.

Anyway, here are a few I've seen around the house and yard. These, I'm pretty sure are steatoda grossa (There are at least 3 kinds called "False black widow," so the scientific name comes in handy here). They're very shy. The widows I photograph just sit around and let me use the flash, the adult grossa outside runs into the plant saucer where he lives (he's bugguide ID'd as a male). The other--the one on the orange and white background--was racing across the bathroom wall, and I never did get a really clear shot.

Then there are the spiderlings: Someone told me they might be widows, but this was corrected: Apparently black widow babies aren't black--in fact, I have a picture of one I'll post tomorrow. Crazy, isn't it?

Spiderlings in the kitchen

Tuesday, November 9, 2010

Silver Argiope at Bolsa Chica

These were all over the prickly pears. Stunning, aren't they? And very alien-looking.

Fortunately for me, there were some in the Bolsa Chica Wetlands building, so I had a quick ID. Also, they are natives to the area, which is always fun (Technically, Brown Widows aren't, but we sure have enough of them around).

Now, I need to learn more about them--like, what do they eat? How long do they live? Where are they when they are not on prickly pear cactus in Bolsa Chica? And so on and so forth.

It's amazingly hard to find lifestyle information on individual spiders. The Widows get a lot of press, but the nice, harmless, bug-eaters that hang around, not so much.

Argentata and very well-wrapped prey.

The Spider by Sabrina Crewe, a book review

Apparently, all spiders are black widows and all spiders have exactly the same life cycle and treat their young exactly the same way. At least, that's the way this children's book approaches things.

If The Spider were titled The Black Widow, or if it mentioned on the first page that it was talking about black widows and only black widows, I might give it a higher rating.  As it is, Crewe doesn't mention until near the end that "Oh, yes, this book is about black widows" and never mentions that other spiders might be different. Verdict? Give it a miss. There are much better books out there.

Monday, November 8, 2010

Spider Byte

"Spider venom comes in many forms. It can often take a long while to discover the full effects of the bite. Naturalists have pondered this for years: there are spiders whose bite can cause the place bitten to rot and to die, sometimes more than a year after it was bitten. As to why spiders do this, the answer is simple. It's because spiders think this is funny, and they don't want you ever to forget them."
          from Anansi Boys by Neil Gaiman

Tuesday, November 2, 2010

Daddy Longlegs Spiders by Jill C. Wheeler

I was attracted to this series because it talks of  individual spider species rather than lumping all spiders together in one, big, undifferentiated mass.  I've read Daddy Longlegs Spiders, Hobo Spiders, and Crab Spiders, all by Jill C. Wheeler, and that remains the series' chief virtue. It is good to see a series of books that recognizes that not all spiders are the same and that realizes that children can cope with this fact.

Otherwise, I'd rate the three as ok. Not great, not awful, ok. The pictures are good and might be useful to a reader of any age who is trying to learn to identify spiders.

I can't tell what age group the text is aimed at. The books are all written in short, declarative sentences which set up a rather monotonous mental rhythm (I would not like to try reading them out loud), but there doesn't seem to be any particular care with the vocabulary; I'd say they have more than their fair share of "long words."

Probably worth checking out in a bag load of library books, but not really worth hunting for unless you've a young spider enthusiast waiting for them.

Monday, November 1, 2010

Spider Byte

During World War II, fine silk threads from black widow spiders in America and from garden spiders in Britain were used for the cross hairs of telescopic gun sights.
        from The Book of the Spider by Paul Hillyard