Spider Photos - Steadota
Spiders of the genus Steadota belong to the spider family
Theridiidae, or the cobweb weavers.
Also known as Combfooted Spiders, this family
includes a number of well known arachnids, including the American
house spider, Achaearanea tepidariorum, and the redback and
widow spiders, Latrodectus spp.. Steatoda spiders are
found throughout the world, in both temperate and tropical climates.
They are small to moderately small (3-9 mm) spiders with oval
abdomens; they may be reddish, brownish or black, with most species
exhibiting a white band at the front of the dorsal abdomen which may
resemble a collar. These spiders construct a strong, irregular web,
somewhat resembling the webs of widow spiders; this web is very
sticky, making it a highly effective snare for hobo spiders which
they are very good at catching. Steadota grossa, the false
black widow spider is the most well known of the Steadota
spiders. Found in cosmopolitan areas around the world, and on both
coasts of the United States, grossa is a larger (9 mm)
Steadota which, as its common name suggests, may resemble a
black widow spider (with no hourglass). Specimens can be reddish to
purplish brown in colour, with pale yellow markings on the dorsal
abdomen, but many specimens are so dark that these pale markings
cannot be distinguished. Steadota grossa is a common and well
known "house spider" in many areas, constructing its webs in and
around buildings, rock walls, and other structures. It has long been
known that the "false black widow" will ensnare, kill and prey upon
actual black widow spiders in its natural habitat.
Many thanks for
allowing us to use the photos sent in. All photos are copyright to their
owners and may not be reproduced without permission.
Please choose a
COMB FOOTED SPIDERS -
23 August, 2006:
Here are some more spider pics from La Mesa,Ca. A lynx spider [looks
like a male] and a couple of these comb-footed species which I wrongly
thought were brown widows. [by the way, thanks for your email reply] I'm
using a cheap 2 meg fujifilm camera so the quality is not so great,but
still... If you can use them please do so. Roy
Reply: The specimen is probably some type of theriid ("comb-footed") spider, possibly
one of the /Steadota/ species. It's not a brown widow.
21 August, 2006:
I have about
three webs attached to different corners of the house each with one of these
in it. I believe they are Brown Widows, can you confirm this? Feel free to
use this photo. Thanks.
Reply: These could be steadota,
false widows that are easily mistaken for brown widows.
10 July, 2006:
Found these in my garage in San Antonio – they are a little unusual
and different than the “normal” Black Widows that I find, although I am
pretty sure they are widows, as – well….apparently while I was cleaning
the garage, I got bit. Pretty classic widow envenomation symptoms. I
found 38 (not including…ummm…probably thousands of spiderlings) before I
had to quit cleaning due to symptoms. I’ll try to get a better picture
when I’m feeling better. The stripes actually look silverish and I
didn’t notice an hourglass – maybe a light brown one? I’ll check and get
some better photos as I know there are more left. Any idea what this is?
Dave B. San Antonio , Texas
More from Dave: Upon further review – even though it made me fairly sick – the spider
IS Steatoda triangulosa (triangulate cobweb spider) According to my
research, it can make you sick (but not like the widows) and, it would
also explain the lack of REAL widows (had them last year – not this
year) as they are a predator of widows. I have TONS of these spiders –
but NO black widows now. Live and learn.
Reply: These could be easily
mistaken for brown widows as I did until I got Cathy's reply from
Dr. John A. Jackman,
Professor and Extension Entomologist,
Department of Entomology: "That is a cobweb spider in the family Theridiidae. The genus on that
one is probably Steatoda. They are common in homes and are considered
harmless to humans.
8 June, 2006:
I know you don't id spiders, but any idea where I could send these to
find out what this is? and of course, if you'd like these on the site,
you are more than welcome to them.
Cathy Webb Garland, TX
Hi Glen, i've been doing a bit of homework on it and may have found out what it is. I
read there was such a thing as a 'false widow' so i typed it into google and
noticed one similar, after following many links i fell upon a picture which
showed a black spider with a red stripe like mine, its name was
'Steatoda Paykulliana' (False Widow Spider was the common name) and
apparently they actually prey upon real Black Widows and would assume Brown
Widows too......shame it died! Not so venomous either.....may be make a nice
safe pet? Check the sites out below for more info, or type steatoda
paykulliana into google. website:
1 February, 2006:
Hi Glen, here's a couple of pictures of the black spider, it had died
overnight by the time these pics were taken so i tried to carefully place it
in a respectable pose with tweezers, it lost 3 legs in my frantic attempt to
capture it alive, I was a bit nervous when i was trying to catch it but I'd
rather it died than me! my camera work isn't brilliant but if any of these
pics are of interest to you for your website you can freely copy and use any
of them at will. When we crushed the egg sacks we missed two, one hatched hundreds of the
little beggars of which i crushed about a hundred then they scattered all over the place ) and the other we put in a jar. Since i last emailed you
I've caught 5 more
brown widows and what looks like it may become a black widow. We have since
lifted up a grate next to where i caught this black spider in the photo and
we found a single egg sack of a smooth nature (not the spiky one) right
where the spider was hiding and have put that in another jar for
surveillance (almost round but ever so slightly egg shaped an cream in
colour). I am very surprised to see widow spiders in Cyprus...no one else believed me
when i said i had some round my house and garden, they said they don't come
from this part of the world it can't be them, and then i checked the net for
photos and found your site which enlightened me to what i was dealing with, so
thank you! you have probably saved me from getting bitten by alerting me to
how venomous they are. I am now treating them with upmost respect. I guess
they are cannabalistic too because one has attacked another and spun a web
round it now and it looked like it was giving it a good bite too. I've thrown
a few live beetles in the tub to keep them occupied too and it seems to be
doing the trick. Two pics one of side view, one of underside view. Look forward to hearing
your verdict! thanks Glen, Paul
Reply: The specimen was some type of
theriid ("comb-footed") spider, possibly
one of the /Steadota/ species (we can't be positive without seeing
an actual specimen). It derives its name from a set of bristles
which are found on the hind pair of legs. These bristles are
used to wrap the spider's prey in silk. This group of spiders
includes the black widow spider but the specimen in your picture is not that species. In general, this particular
species does not pose a
health threat to people or pets. However, just as with bee or wasp
stings (which have a very different venom), people will exhibit
varying degrees of sensitivity to a bite. I don't consider the
use of pesticides as necessary. Preventive spraying for
spiders if difficult because they move around and finding a "target
site" to treat is difficult. Plus, longevity of the chemical in
being effective against spiders depends on many factors. Simply
removing the spider is a simple and effective control. (Entomologist
- State Centre)
11 June, 2006:
Hi, great website. Any idea on what kind of spider this is?
She's got red
diamonds down the back in a patter with black..found her underneath my pool
skimmer. never seen this before.
In sunny Phx, AZ Any help would be great!!!
26 January, 2006:
Hi. Background info: Just before Christmas, whilst doing some
rebuilding to my garage, I removed
a load of old cobwebby timbers from a dusty old storeroom in the old chapel here
in England where I live and found, somewhat to my astonishment, two shiny black
spiders of a type I had never seen before; both had bodies much larger than
their heads, (body size about the size of a chick-pea, and leg span slightly
bigger than a 10 (or 2) pence piece); both had two coloured
triangles on the back of their abdomens, one set an orange cream colour, and the
other set more of a brown/grey; these triangles were not red, nor were they in
an hourglass formation, rather both pointed towards the head, one in front of
the other - (similar in size and position to the hourglass formation, but with the top half swivelled the other way up). One spider was
slightly bigger than the other. I insinctively felt fear and danger,and my head spelt out 'Black Widow'. These shiny specimens seemed to belong
more to a sinister science fiction film or an S&M flick rather than to mygarage. I put on some gloves and caught both with a sheet of paper and a
cup. I looked up what I could find on the internet - the closest match was a Black Widow spider, except for the fact of the markings on the back -
classic Black Widows have a red hourglass. These didn't, although size and body shape were identical. I read a certain amount about the toxicity of
the bite of the Widow, their reclusive nature, their love for warm countries, and was surprised that I found these alive and well in December
in England. Uncertain and a little spooked, I knew I wanted these two away from my house, so I walked a few hundred yards down the road and flung them
from my cup into a hedge on a wet and cold night, thinking they probably wouldn't survive long.
Until two days ago there has been no further sighting.
Whilst repairing my garage door, I found another spider, slightly smaller than I remember the other two being, but again, shiny and black,
dangerous looking, identical to those from before. I have caught it and put it in a cup. It has two coloured arrows on its abdomen facing its head in a
brown/mahogany colour. I have tried to take some good photographs to send, but because the subject is in a white mug, it is dark and so the flash goes
off and reflects off the white glaze, and because I need a reasonably lowresolution to send over the internet, the shots are not great. But they
will give you an idea of what's going on. They are added as an attachment
to this mail.
I need to know what this spider is, if there is any potential danger or not.
I have taken the spider to a local amateur 'expert' who informed me that it
was definitely a 'cave spider', (meta menardi), without really actually
looking at it and subsequent searches on the internet show that this is
obviously not the case. It has a totally different shaped body and
markings, not to mention overall colour. The only photograph I can find
which is a definite match is actually on your website under the title of
'steatoda grossa' - the web address is:
A search on Google for 'steatoda grossa photo' reveals pages containing
photos of numerous spiders which look very different, yet are all still called 'steatoda grossa'. Is this because people are just being inept, or
perhaps because many variations are possible?
The subject is now deceased due to a certain amount of ineptitude on my
part. An attempt at picking it up with a sheet of paper resulted in a
awkward scrape which burst the abdomen sac, which subsequently oozed out
brown goo, the abdomen deflated and the spider died. So no chance of a
better photograph. I'm sure I will find more specimens in time. If there
were three, there's bound to be another somewhere. This was probably a baby
from the two larger ones from before xmas.
I'm used to living in a country where the danger comes from people, not from
little eight-legged beasties that have stepped off of the set from The
Matrix! From what I have read on the 'net the bite from Steatoda Grossa is
similar to although a lot less severe than a bite from the Black Widow, and
should be treated with the same antivenom if possible if an allergic
reaction happens, otherwise just hang in there until the body sorts itself,
usually with a reaction like a bee sting.
What do you guys think this is?
Any thoughts regarding this matter would be most helpful. If you are unable
to identify this spider, but know of a person who might be able to, perhaps
you could pass on some details? That would be most kind.
Another Reply: The Steatoda sent
in on Jan 8th is a borealis sp. See a pic
Reply: It has the same body shape as
the black and brown widow and probably belongs to the same family of comb footed
http://hobospider.org/steatoda.html - glen
8 January, 2006:
Glen, I just discovered your terrific website trying to identify what
this spider might be. It resides in our basement in Portland, Oregon; is about
3/4 inch altogether--abdomen a little under 1/2" with distinctive red color but
no other markings. Doesn't move much--just perches outside this hole in the
concrete until something comes along it would appear. Thanks for any help
you can offer. Chris
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