Black widow spiders are one of the most infamous and feared spiders in North America. The adult female black widow is the one with the venomous bite that can cause severe pain, nausea, headache and other symptoms in humans. Their shiny black body and characteristic red hourglass marking on the underside makes them easy to identify.
However, there are many other spiders that are commonly mistaken for black widows due to their similar appearance Some of these spiders can also deliver a painful bite, while others are completely harmless
In this article, we will look at 8 spiders that are often confused with black widows, how to tell them apart, and whether they pose any danger.
How To Identify a Black Widow Spider
Before looking at lookalike spiders. let’s recap the main ways to identify a black widow
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Adult females have a shiny, rounded black abdomen and legs. They range from 0.39-0.59 inches (10-15 mm) in body length.
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A red or orange hourglass shape on the underside of the abdomen. This may range from bright red to orange-yellow.
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Females often have a red/orange dot on the dorsal side. Juveniles and males have stripes and spots on the back.
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Build irregular, tangled webs near the ground.
8 Black Widow Lookalike Spiders
1. Brown Widow Spider
Frequency in provided URLs: 1
Brown widows can be easily confused with black widows, especially the juveniles of both species. They have a similar dark brown to black coloring and bulbous abdomen shape.
However, brown widows can be identified by:
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Hourglass is orange to yellow, rather than bright red
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Presence of black and white patterns on the sides of the abdomen
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Legs banded with light and dark coloring
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Size is smaller, 0.28-0.43 inches (7-11 mm) in body length
The brown widow is not as venomous as the black widow. Their bites can be painful but are less likely to produce severe reactions.
2. Noble False Widow Spider
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The noble false widow is the largest of the false widow group, with females reaching 0.51-0.59 inches (13-15 mm). Their legs and bodies are more brown than black. The abdomen can range from a pale cream color to dark brown or black, and may lack markings completely.
Unlike black widows, noble false widows do not have the red hourglass on the underside. Their bites are also not medically significant to humans.
3. Cupboard Spider
Frequency in provided URLs: 2
Also known as the false black widow, this spider closely mimics the appearance of the black widow. The female has a similar bulbous black abdomen. However, the color tends to be more reddish-brown or purple-black rather than a glossy black.
They also lack the red hourglass on the underside. If they do bite, it can be painfully but is not as toxic as the black widow.
4. Triangulate Cobweb Spider
Frequency in provided URLs: 1
This spider gets its name from the triangular marking on the abdomen. It has a brown to orange cephalothorax and cream abdomen with purple zig-zag patterns down the middle. With a maximum length of 0.25 inches (6 mm), it’s much smaller than a black widow.
The triangulate spider doesn’t pose any danger to humans. Its bite is not harmful.
5. Rabbit Hutch Spider
Frequency in provided URLs: 2
As the name suggests, this species often inhabits rabbit hutches, but can also be found around homes, in gardens, bushes and under stones. They grow to around 0.3 inches (7mm) and have a brown abdomen with a pale stripe down the center.
An infinity shape symbol can often be seen on the underside. Rabbit hutch spiders rarely bite, and it is considered harmless if they do.
6. White-Spotted False Widow
Frequency in provided URLs: 1
Ranging in color from plum red to pale brown or black, the white-spotted false widow has characteristic white, orange or beige patches on its bulbous abdomen. It builds webs in dark, undisturbed places in the home.
Though not medically significant, they can deliver a painful bite out of self-defense. They lack the red hourglass marking.
7. European Black Widow
Frequency in provided URLs: 1
This close relative of the black widow can be identified by the 13 yellow, orange or red spots on the upper abdomen, rather than the single red hourglass. They can reach up to 0.6 inches (15mm) in body length.
Though rare, their bites can potentially be medically significant, even life-threatening in some cases.
8. Redback Spider
Frequency in provided URLs: 1
Native to Australia, the redback spider is also black with the red stripe on its dorsal side. The hourglass marking on the underside tends to be orange-red. Only the females are venomous. Bites cause intense pain that can persist for hours.
Protect Yourself from Black Widow Bites
Black widows tend to live in dark, cluttered spaces outdoors and occasionally find their way indoors. To limit potential encounters:
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Keep woodpiles and debris cleaned up around the home’s exterior
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Carefully inspect items like patio furniture before moving indoors
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Wear thick gloves and long sleeves when cleaning sheds, garages and basements
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Shake out shoes and clothing left outside before putting them on
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Install insect screens on windows and doors
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Use glue traps or contact insecticides in problem areas
Though many other spiders resemble them, understanding the key ways to ID the black widow along with where they live can go a long way in prevention. Being able to distinguish lookalike species that are harmless can also prevent unnecessary worry.
What Do Widow Spiders Look Like?
Spider younglings are often hard to distinguish from other spider species. Most adult female widow spiders have a glossy-jet black coloration, a red or orange hourglass, or similar such marking on the underside. They are about the size of a ½ dollar coin spin a “sticky,” irregularly shaped web.
To further complicate matters, male widow adults are smaller than typical female adults. Males can have reddish and whitish makings on the top, not the underside of their abdomen, with shapes that include stripes or spots as well as an hourglass.
Black Widow Spider Close Up
Insect experts classify true widows in the genus Latrodectus. True black widow spiders found throughout the United States include the southern black widow (Latrodectus mactans) the northern black widow (Latrodectus variolus) and the western black widow (Latrodectus Hesperus).
Spiders That Look Like Black Widows but Aren’t
Immature brown widows and western black widows look very much alike when they are young. Adult brown widow females have a reddish hourglass marking on the bottom of the abdomen, but are often more of a tan or dark brown color rather than black.
However, this color distinction is not always easy to see. A black widow with an hourglass marking will display the shape prominently, whereas brown widows will have a less distinctive, duller marking. Also, brown widow bites are less painful than the bite of the western black widow.
Adult female red widow spiders are reddish-orange, with reddish colored legs and a black or dark colored abdomen. The top of the abdomen usually has rows of red or orange spots outlined in white or yellow. Females lack a complete hourglass shape on the underside of the abdomen. Instead, they usually have one or two small red marks that look somewhat triangular.
This spider does not have the red hourglass marking and is a glossy chocolate brown colored spider. It shares the same rounded-abdomen body form and web-making traits as the true black widow spiders. However, this spider is slightly smaller than a mature western black widow spider. False black widows can bite if picked up or otherwise touched, but its bite is rare and is not considered a medically important spider.
This spider is somewhat rare in the United States, but is found in California. The adult female has a bulb-shaped abdomen much like the widow spiders. But the abdomen is brown and has cream colored markings similar in shape to a skull. Bites are very rare. Symptoms are minor and discomfort due mostly to the pests large fangs.
Adult domestic house spiders, also known as the barn funnel weaver spider, are reddish-brown and have a pale, freckled abdomen. Their bodies do not have the hourglass marking, vary from gray-brown to dark brown and have two dark colored stripes on the cephalothorax.
The black house spider is a dark colored spider, more bulky and awkward in appearance than widow spiders. Both males and females have dark brown legs and a gray abdomen with light markings on the top of the body. These spiders can bite if disturbed, but are not aggressive. They usually try to escape rather than bite.
The Black Widow Spider: Everything You Need To Know!
FAQ
What spiders are mistaken for black widows?
Noble False Widow Spider (Steatoda nobilis)
The adult female has a bulb-shaped abdomen much like the widow spiders. But the abdomen is brown and has cream colored markings similar in shape to a skull. Bites are very rare. Symptoms are minor and discomfort due mostly to the pests large fangs.
How to identify a false black widow?
False black widows (usually Steatoda grossa) have a round and slightly flattened abdomen with no underside (ventral) markings. An immature individual has white markings on its upper abdomen, usually with a white horseshoe in the front.
How do you tell if a black spider is a black widow?
Hourglass marking: Black widows are identified by red hourglass markings on the underside of their abdomens. This marking is bright red and signals danger to predators and attackers. Color: Black widows are shiny black in color. Size: Most black widow spiders’ bodies are 3 to 10 mm in size.
How can you identify a female black widow spider?
Female black widow spiders are easily identified by the red hourglass on her belly with a shiny black body. In North America, there are a number of black widow species. Males have red and yellow bands and spots on their backs, longer legs, and smaller bodies. Juveniles look like males.
What kind of spider looks like a black widow?
It’s one of five black widow species found throughout North America. This will get your spidey sense tingling: There’s a type of spider that looks like a black widow—but packs a much less potent bite. False widow spiders resemble their infamous cousins, black widow spiders, with spindly legs and globe-shaped bodies.
What is a brown widow spider?
The brown widow spider (Latrodectus geometricus) is related to the black widow but is not as dangerous. It has black and white patterns on the side of its abdomen and an orange to yellow hourglass shape.
What do false Black Widow Spiders look like?
False black widow spiders are dark brown to black in color, typically measuring around 6 to 10 millimeters in body length. They may have lighter markings or patterns on their abdomen.
Are black widow spiders similar to wolf spiders?
Male black widows tend to be smaller and lighter in color than females, so it is easier to confuse them with wolf spiders than it is to confuse the females. That said, if the spider in question is not near a web, there’s a good chance it’s a wolf spider instead of a black widow.
Are black widow spiders venomous?
Female black widow spiders are the most dangerous and are easily identified by the red hourglass on her belly with a shiny black body. Their venom is potent and can cause serious health issues. Males and juveniles, however, are not dangerous and can be differentiated by their red and yellow bands, longer legs, and smaller bodies.