Currently viewing the category: "Cobweb Spiders"
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: Strange Spider?
Location: Upstate New York
July 11, 2017 9:14 pm
Dear Bugman,
My son and I located what we believe to be some sort of spider weaving a web under our porch light. We were quite curious as to what type of spider it might be. I am thinking some type of Orb Weaver? Any help would be greatly appreciated. So sorry for the quality of the photos, the bug was quite small. Thank you.
Signature: Heather

Cobweb Spider

Dear Heather,
We believe we have correctly identified your spider as a Cobweb Spider in the family Theridiidae, and it is a species without a common name,
Rhomphaea fictilium, thanks to this BugGuide image.  According to BugGuide, it is:  “widely scattered in the U.S., but reportedly rare; also throughout most of Canada.”  We located this interesting information on Spiderbytes:  “As well as having wonderfully strange morphology, Rhomphaea have rather unusual habits. Most spiders are generalist predators, and spiders in the family Theridiidae typically build tangle webs that they use to catch crawling insects and other arthropods, including other spiders. Rhomphaea, unlike most of their relatives, specialize on hunting other spiders. They do sometimes build their own rudimentary webs from just a few silk lines, but they also enter the webs of other spiders and use aggressive mimicry to hunt their owners. Rhomphaea will pluck the web and produce vibrations that lure the resident spider out to investigate what they perceive to be prey caught in the web. The web-building hunter then becomes the hunted, tricked into the approaching the dangerous intruder. Rhomphaea fictilium have been reported to prey on other theridiids, orb-weavers (araneids), sheet-weavers (linyphiids) and others.”

Cobweb Spider

Wonderful!  Thank you so very much for your help.  It was fascinating to read about this spider.
Thank you,
Heather

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: Parasteatoda Tepidariorum Spiderlings
Location: Upper Texas Coast
July 4, 2017 11:38 pm
The American house spider (Parasteatoda tepidariorum) that lives in my bedroom recently produced this crop of tiny spiderlings.
Signature: Lachlan

Common House Spider with Spiderlings

Dear Lachlan,
Thanks so much for sending in your image of a Common House Spider and her spiderlings.

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