Species Spotlight: Black Widow Spiders

Written by:  • Edited by: Niki Fears
Updated Oct 5, 2009
• Related Guides: Spider

This article discusses the habitat, diet, reproductive habits, lifespan and venom of the Black Widow Spider.

The Black Widow Spider is actually a group of spiders. This group includes the western black widow spider, the southern black widow spider and the northern black widow spider. This spider can be found throughout most of the United States as well as in parts of Canada and Mexico.

Diet, Reproduction & Behavior

Black Widow
click to enlarge
The Black Widow Spider usually preys on other insects, but they will occasionally prey on other spiders, woodlice, chilopods and diplopods as well. Most of their prey is captured when they become entangled in the webs of the black widow spider and once they are ready to feed on the prey they bite them to inject the venom and then hold them tightly for the approximate ten minutes it takes for the venom to take effect. Once their prey is dead they bring it back to their retreat and then feed on it.

Female Black Widow Spiders typically produce four to nine egg sacs at a time and each sac can contain anywhere from one-hundred to four-hundred individual eggs. Black Widow Spiders reproduce in the summer and the eggs will need to incubate for an average of twenty to thirty days. Typically, only thirty eggs will survive the initial molting and for those that survive it takes an average of six to nine months for the baby spiders to fully mature into adults. On occasion, the female Black Widow Spider will eat the male after they have mated. Female Black Widow Spiders have a lifespan that lasts approximately five years, but the males will typically have a much shorter lifespan.

Despite their small size, Black Widow Spiders possess a very potent venom. It has been said that their venom is more powerful than that of coral snakes and cobra snakes. The venom of a female Black Widow Spider is more harmful than that of the males, but the likelihood of death is relatively small though the side effects can be very unpleasant. The venom from these spiders is more powerful than the venom of most other spiders. Their venom is considered neurotoxic and there are several active components in it such as Latrotoxins and Adenosine.

Think you've been bit by a spider? Find out some spider bite home treatments.

Photo Credit

http://commons.wikimedia.org/wiki/File:Black_widow_ventral_1370.jpg


Comments

Showing all 24 comments
 
Frhgft Nov 30, 2011 4:02 PM
RE: Species Spotlight: Black Widow Spiders
and what
wanda Mar 11, 2011 9:43 PM
food
I inherited a 1.5 year old BW spider in a big jar. I gave it 2 crickets and she ate them but how often does she need to be feed? She is very big. Thanks Wanda
someone Jan 31, 2011 7:51 PM
thanks
umm this peice of righting has really
helped me . so I would like to say thank who ever wrote it .
R. Elizabeth C. Kitchen Jan 5, 2011 12:38 AM
Susan
Be very careful. If there are a lot of them, maybe a pest service would be a good idea. A pest service could remove them for you so that you do not have to worry about being bitten.
Susan Roberts Jan 4, 2011 9:23 PM
Black widow info
Hi, I just cleared out a storage unit which I have had for about 4 years. It has been really cold, around 10 to 20 degrees in the day and at night it drops into the negative numbers. The storage unit was unheated but I don't know if I should be worried about bringing spiders or their eggs into my home in all the boxes. We have black widows in this part of Utah, I rarely ever have seen any indoors. How carefull do I have to be as I empty out my boxes. Thanks.
Jaden Jan 2, 2011 8:37 PM
thanks
I used this for a science report and it helped me alot thanks for posting this article!
Jennifer-Rose Nov 2, 2010 12:32 PM
RE: Species Spotlight: Black Widow Spiders
how much do black widow spiders eat?
Jennifer-Rose Nov 2, 2010 12:31 PM
Black widow spiders
can someone tell me how much black widow spiders eat please.
Jennifer-Rose Oct 19, 2010 2:08 PM
what do black widow spiders eat?
can you please tell me what black widow spiders eat?
angela Sep 6, 2010 9:56 PM
black widow males
does anyone know a buyer of these?
Laurie Patsalides Mar 26, 2010 1:56 PM
Hi Alice
With all due respect, these comments are monitored by a real person who reads and writes in English. That being said, we have a young student audience, so please be mindful of that when posting comments.
Best,
Laurie Patsalides
Managing Editor
Christine H. Stark Mar 26, 2010 1:46 PM
Black Widows
I was fearful when I gave my Fluffy a 'Superworm' because the worm really thrashed around, Fluffy bit and bit and bit as the worm did not slow down from the effects of the venom and he could have been hurt. I read somewhere too that a B W was bit and subquently eaten by a cricket Eventually Fluffy won and had his supper. I think the skin is too hard on the Superworm and the venom couldn't penetrate.So much for superworms.
Jezzie Feb 26, 2010 3:37 PM
thanks
i had to use this for a project and it was helpful, just wanting to say thank you for taking time to post!
Alice Feb 15, 2010 3:12 PM
BLACK WIDOW
I was just curious when my comment would be added to these others. I sent it in about a month ago and I don't believe that I have seen it as of date. If there i a problem I will be glad to straighten it out, otherwise I feel I have quite a bit of information for these kids. Id appreciate it if you could add it to the comments and if you would like I can write another and send it to you as well.
Christine H. Stark Jan 20, 2010 1:21 AM
black widow spiderlings.
Google 'Black Widow Spiderlings 'and you will find lots of interesting stuff including a video of babies coming out of the half inch diameter egg sack. The mama will eventually eat them if they don't escape. The male and the spiderlings are harmless and now I wonder if my 'Fluffy' is a fellah.
chizzel Jan 18, 2010 3:59 PM
care
I found my second one all balled up in a doorway floor.Fed her and she came around, now she has an egg sac for over amonth now.Do I need to seperate the sac from her? The sac is brown and the size of a marble. It was my understanding they were grey and the size of a pea.
gswg Jan 13, 2010 11:44 AM
aliveah
cool
Christine H Stark Jan 9, 2010 12:58 AM
RE: Species Spotlight: Black Widow Spiders
My guy, Fluffy, has a rapacious appetite. I bought small worms from the pet shop and I put them one at a time near his 'pillbox'. He comes right out and eats it straightaway every time. He has doubled in size.
I will get him the bigger ones next time. The weather is too cold for flies so far and it was fun to watch him 'go after' the buzzing pest. By morning, twas a done deal,,, and now he just 'grabs' the worm.
He likes his hideaway and drags the worms within.
I keep him on the kitchen counter and love to watch him do his thing.
I spritz his place with a fine spray of distilled water every day.
He doesn't seem to need a lot of space but I find it convenient for me to have the space to put my hand in and put the worms near within his hideaway. He can move pretty fast when he wants to tho.
I have his picture on Facebook... check it out.
dennis Jan 9, 2010 12:14 AM
notification
i want to be notified
dennis Jan 9, 2010 12:12 AM
black widow female
caught mine about 5 months ago and she is beautiful. fed her flies until weather changed and now get crickets from pet store. she loves them and almost doubled in size after feeding her. i have her in insect large box that i covered wit a screen. hoping that she may produce off-spring. dont doubt it cause had another for bout 3 months in smaller box late summer fed flies til i seen on internet someone feeding theres a lizard, i went straight and caught 2 small lizards put in her cage and she doubled in size over nite and three days latter produced an egg sack. unfortuneately i had put her outside while fixing box for the second one i caught and a heavy rain and super cold front came through and froze her and egg sack. hoping that second one, which im making sure doesnt fall to same fate will produce an egg sack. very interested in this species. she has perfect coloring and is now about the size of a average marble.
Christine H. Stark Dec 20, 2009 11:02 PM
Black Widow Spiders
My guy is becoming bigger and i wonder if it might be a female. I once saw one in my yard and it was gigantic so I figured twas a female. This one ismuch smaller so I figured must be a boy... but who knows...I'm still working on his habitat and when I finish, I hafta figure how to get him into it.
He worked very hard on his web and it is very thick and he doesn't want to go too far from it.
Elias Garcia Sr. Dec 20, 2009 4:59 PM
I Caught one too
i recently came across this site when my son decided he wanted to look up information on black widows i"ve done the same wit my black widow i caught 4 months ago i feed her the same thing i feed fat flies daily i just go out side wit a jar an i sneak up em an caught em she lives in a jar that's about 11 inches high an about 10 inches in diameter an shes a beauty shes real shiny all black an red
Christine H. Stark Dec 19, 2009 11:59 PM
Black Widow spider
About a month ago, I found and captured a widow for whom I made a habitat out of a big plastic jar which is 11" tall with a 2' circumference.
I capture flies for him and make certain there is always plenty for him to eat.

I want to know if you think he needs more space??

Does he need space to roam around?

I plan to put a plastic 'pill' container for him in case he wants to hide or sleep.
I am working on the 3rd prototype to make it easier to clean up his discarded flies by putting the twist off cover on the bottom.

I put another jar atop his jar, but he does not seem to want to leave his web.

I don't know his age but already he molted.

thanks

Alexuis Dec 8, 2009 2:27 PM
RE: Species Spotlight: Black Widow Spiders
bleck widows are very dangerous and
 
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