Currently viewing the category: "Black Widow"
What's That Bug? does not endorse extermination

Subject:  Black Widow Spiders
Geographic location of the bug:  Northern New Mexico
Date: 10/04/2017
Time: 12:05 AM EDT
Good evening.
I moved to Santa Fe from Southern Oregon four months ago for work and I have never encountered female black widow spiders like this. We have killed eight large, female specimens in the house over the past two days.  Most of them were on the move in broad daylight, and surprisingly aggressive.  Two of them were actively sharing a web.  I captured one in my bathroom, and confirmed the red hour glass. I’ve never known female widows to act like this, unless defending egg sacks. Is this a sub species native to New Mexico, or some sort of infestation I was previously unaware of?
How you want your letter signed:  Alexa Rense

Black Widow

Dear Alexa,
According to BugGuide:  “The
Latrodectus genus breaks down taxonomically into approximately 31 recognized species, five (5) of which are found in the United States; four (4) species are native, one (1) species (L. geometricus) was introduced.”  According to BugGuide data, it is the Western Black Widow that is found in both Oregon and New Mexico.  While the bite of a Western Black Widow can be dangerous, they are not an aggressive species, though many female spiders will defend eggs and young.  We are lamenting the loss of native Western Black Widows in Los Angeles where they seem to have been entirely replaced in recent years by the invasive Brown Widow.

What's That Bug? does not endorse extermination

Subject: Is this a Black Widow Spider
Location: Johnstown, PA
August 21, 2017 2:53 pm
My name is John and I am the safety director for a company based out of Johnstown, PA. Earlier today, August 21, 2017 I was approached by two mechanics working on a truck with a concern over a spider. Today was the day of the eclipse and was a very nice warm day, temperature mid to upper 80’s. the spider was located in a sealed portion of the truck that under normal circumstances is very dark. there was a repair needed in the area so a hatch was opened up to reveal the webbing and the spider. After multiple people viewed the spider there was an ensuing debate on whether it was a Black Widow or not. Please help.
Signature: John Gregorchik

Black Widow

Dear John,
Because of the red hourglass marking on the ventral surface, we are 100% confident this is a female Black Widow Spider.

What's That Bug? does not endorse extermination

Subject: Is this a Dangerous Spider – Sure looks like it to me
Location: West Los Angeles
July 10, 2017 5:39 pm
Hi Bugman,
As much as I love butterflies, I don’t get along with spiders. Can you please let me know if this one is dangerous?
These are the best pics Icould take, but if you enlarge them the spider is quite visible.
Thanks,
Signature: Jeff Bremer

Brown Widow and Egg Sac

Dear Jeff,
Both the Brown Widow Spider and her egg sac which are pictured in your image are quite recognizable.  According to BugGuide:  “The brown widow is highly variable in color. It may be almost white to almost black. Typically, it is a light to medium brown, with an orange-to-yellow hourglass marking on the underside of the abdomen; the coloration of the hourglass often is a good indication of this species. The leg segments are banded, with one half of each segment lighter in color than the other half. The back often has a row of white spots (rarely orange or light blue), and there are a few white stripes on each side. Darker individuals lack these markings and are difficult to distinguish from black widows. If an eggsac is present, this is the best identifying characteristic. Brown widow eggsacs are tan, spherical, and have many small tufts of silk sticking out from them. They resemble a ‘sandspur.’ The other widows make white, smooth eggsacs that tend to be pear-shaped. ” BugGuide also provides this information:  ” Widow Bites:  NOTE: It is recognized that this particular species of widow is most likely not medically significant (not an immediate medical concern to those who are bitten). The brown widow produces clinical effects similar to that of the black widow but the typical symptoms and signs being milder and tending to be restricted to the bite site and surrounding tissues. (Print Ref 1)  Brown widow spiders usually curl up into a ball, and drop to the ground as a primary defense. It is highly recommended that people leave this spider alone; observe, but don’t touch.  The brown widow is an extremely timid spider which has rarely been reported to bite.”  The Brown Widow is a non-native, introduced species that has gotten quite common in Southern California as well as the entire southern portion of the U.S.

Thanks Daniel,
It’s hard to know when to be worried and when not.
Jeff

What's That Bug? does not endorse extermination

Subject: Found in grapes
Location: Southeast Michigan
June 1, 2017 7:28 pm
My wife was bitten in the finger as she was packing some grapes in a bag. We live in southeast michigan but not sure where the grapes come from
Signature: Bill Lowry

Brown Widow Spider

Dear Bill,
This sure looks like an immature Brown Widow Spider,
Latrodectus geometricus, to us, but viewing through the plastic bag is somewhat distorting.  Here is a BugGuide image for comparison.  The Brown Widow is a recently introduced species According to BugGuide:  “World wide in the tropical zone. It was introduced in Florida and has since been observed moving north through Georgia, and into South Carolina; it has also been officially recorded in California, Alabama, Mississippi, and Texas.”  If the grapes were imported from California, it is entirely possible that a Brown Widow was imported with them.  BugGuide also notes:  “Widow Bites:  NOTE: It is recognized that this particular species of widow is most likely not medically significant (not an immediate medical concern to those who are bitten).  The brown widow produces clinical effects similar to that of the black widow but the typical symptoms and signs being milder and tending to be restricted to the bite site and surrounding tissues.   Brown widow spiders usually curl up into a ball, and drop to the ground as a primary defense. It is highly recommended that people leave this spider alone; observe, but don’t touch.  The brown widow is an extremely timid spider which has rarely been reported to bite.”

What's That Bug? does not endorse extermination

Subject: Australian Redback in Louisiana?
Location: Leesville, Louisiana
May 4, 2017 8:35 pm
I’ve found several of these spiders over the last two years. They have red markings on the back unlike black widows that have a red hour glass on the abdomen. I also noticed some white markings as well. Curious if this could be an Australian Redback???
This one was released back to the woods this evening. May the 4th be with him.
Signature: Thanks, Lee

Immature Black Widow

Dear Lee,
This is an immature female Black Widow Spider.  When she matures, she will lose the red and black markings on the upper surface of the abdomen.  She should still have the red hourglass marking on the ventral surface.  Your confusion regarding the Australian Redback Spider is understandable as they are in the same genus as the Black Widow.  P.S.  Is your town named for you?

What's That Bug? does not endorse extermination

Subject: Spider ID please
Location: Cochise County, Arizona
April 25, 2017 4:55 pm
Hello Bugman,
I found this spider in a space between a door and the screen. It is shiny and I first thought of black widow but it doesn’t have the red hourglass on the abdomen. What it can be? I appreciate your help so that I can open that door again.
Signature: Kana

Immature Western Black Widow

Dear Kana,
This is definitely an immature Widow, probably a Western Black Widow.  Here is a matching image from BugGuide.

Dear Daniel,
Thank you so much for your quick reply. I have never seen a black widow spider and wanted to know where they live (to avoid them). Never imagined they live so close!
Kana
What's That Bug? does not endorse extermination