Have you seen a small black spider crawling in your home? It might be a baby black widow spider. In this article, I’ll describe what baby black widow spiders look like and many facts about these rather attractive-looking spiderlings.
What does a black widow baby spider look like? At the start of their maturation period, baby black widow spiders have a metallic mahogany hue with a stripe in the middle and diagonal streaks on the sides. When they emerge from their eggs, they have a white body with tan or mahogany legs.
In this spiderling phase, they are very tiny, no bigger than a pinhead. They have underdeveloped fangs without enough venom. So, they are practically harmless during this time.
The black widow spider has 31 species and belongs to the genus Latrodectus. Five of its main species are in the United States. The adult black widow spider is the most venomous spider in North America but is rarely fatal for humans.
Read on to learn more about black widow baby spiders, their appearance, and other interesting facts about them.
Baby Black Widow Spider Facts
The life cycle of the baby black widow spider starts during the adult widow spiders’ mating season. It occurs from springtime up to early summer. After copulation, the female black widow would kill and eat her mate, which is how they got their name. The reason behind this sexual cannibalism is that the female will have a readily available protein source to fertilize the eggs now developing inside her body.
In the summer months, the female black widow creates several silken egg sacs measuring 12 to 15 millimeters in diameter. The sacs are tightly woven cups with a paper-like texture. They appear white, gray, or tan and can contain 200 up to 900 eggs. You can typically find black widow eggs in dark crevices underneath stones, woodpiles, and other natural debris.
After around 30 days, the eggs hatch and give birth to hundreds of baby black widow spiders. But like their parent, black widow babies are also cannibalistic by nature. They will most likely consume their siblings for sustenance. Only a few hatchlings will survive the 3-month development to adulthood.
Appearance and Maturation of the Baby Black Widow Spider
Within a few days, the baby black widow spiders would leave their web and experience ballooning. They would release silken strands into the air, forming into a balloon that carries them to new locations. Eventually, the spiderlings will learn how to spin their own web to catch their own food. They will then find a suitable shelter to survive the winter until they develop into adulthood when warm weather comes.
The maturation period of the baby black widow spider lasts from the wintertime to the following spring. At first, a black widow baby is white and tan in color. It has a metallic mahogany hue with a stripe in the middle and diagonal streaks on its sides. In this phase, they are very tiny, no bigger than the head of a pin. They are also practically harmless since they have underdeveloped fangs without enough venom.
As they grow older, they go through stages of molting, known as instars. Their outer skeletons gradually develop, and their color and pattern begin to resemble the appearance of adult black widow spiders. The male of the species, however, tends to retain some of their original patterns. However, the females take on the familiar form and dark coloration of the black widow.
Appearance of the Adult Black Widow Spider
Male and female black widow spiders look very different from each other, with females being more representative of their species’ defining characteristics.
Fully-grown female widows are usually around 1.5 inches long. They are either shiny black or dark brown in color. Moreover, they have a red or orange-colored hourglass-shaped mark on the ventral surface (underside) of their abdomen, with a pair of red spots sometimes.
Black widow spiders can range in size from 3 to 10 millimeters (0.12-0.39 inches). Male widows are much smaller than their female counterparts, coming in at about half their size.
They are typically lighter in color, often with red, red and white, or pink markings on their abdomen’s dorsal surface (upper side). The patterns range from spots or bars to a single stripe on their backs. Also, their appearance closely resembles that of the black widow baby spiders.
If the spider looks more brown than black, see our article on baby brown recluse spiders.
Life Span of the Black Widow Spider
The life expectancy of a black widow spider is typically one year. However, some of them can survive for up to three years. Such spiders live the longest in captivity.
Where Do Black Widow Spiders Live?
Black widow spiders are usually found in regions with a temperate climate, such as Africa, Australia, Asia, South America, Southern Europe, and the United States, mainly in the South and West.
Widows prefer to make their homes in dark, dry, and undisturbed places close to the ground. These spiders usually prefer woodpiles, construction openings, trash, dense vegetation, or small holes made by animals. In other words, they nest in dark indoor places like barns, basements, garages, or under desks and furniture.
What/How Do Black Widow Spiders Eat?
Typical of other spider species, the black widow spider feeds on insects, such as beetles, caterpillars, flies, grasshoppers, and mosquitoes. They also feed on other arachnids.
The female black widow hangs upside down from the center of her spider web and shows off the bright markings on her body to catch food. For other potential predators, the markings are a sign that she is poisonous. But if her prey gets attracted to her colors, it ends up getting entangled in her web.
Once caught, the black widow spider incapacitates the prey with her venom and wraps it in silk using her comb feet. She then bites it with her fangs, injecting it with digestive enzymes to liquefy its body.
This process enables her to suck the fluid remains into her mouth. If she senses a threat, the widow quickly escapes by sliding herself down to the ground on a strand of silk.
How Deadly Is the Black Widow Spider’s Venom?
The black widow spider is widely considered the most venomous spider in North America. Reportedly, their venom is 15 times more potent than that of a rattlesnake. To most people, a widow’s bite initially feels like a pinprick, but the onset of pain occurs in a few minutes and eventually spreads to the rest of the body.
The effects of a black widow’s venom depend on the species. But general symptoms include:
- Hyperhidrosis (profuse sweating)
- Muscle spasms
- Muscle pain
Other symptoms may include:
- Severe abdominal and back pain
- Tachycardia (fast heart rate)
- Difficulty breathing caused by paralysis of the diaphragm
The pain usually lasts for 8 to 12 hours, while other effects may last for 3 to 7 days or even up to several weeks.
Despite this, the bite of a black widow is rarely fatal to humans. The bite of a female widow is considered a danger to human health, especially to the very young, the elderly, and the sick. However, most victims don’t sustain any serious damage.
Typically, treatment involves giving black widow antivenom to relieve pain and minimize damage rather than save lives. In the first place, black widows are not very aggressive and rarely bite people. They only do when they are startled or feel threatened.
We’ve described what the baby black widow spider looks like; next, let’s look at the different species of the black widow spider.
Species of the Black Widow Spider
The black widow spider belongs to the Theridiidae family. It is generally referred to as ‘comb-footed spiders’ because of the presence of short, stiff hairs in the last section of their fourth pair of legs. These hairs also resemble a comb’s teeth.
Although Latrodectus spiders are commonly known as black widows, other spiders of this genus are also known as brown widows and red widows. According to ITIS (Integrated Taxonomic Information System), the taxonomy of the black widow spider is as follows:
- Kingdom: Animalia
- Subkingdom: Bilateria
- Infrakingdom: Protostomia
- Superphylum: Ecdysozoa
- Phylum: Arthropoda
- Subphylum: Chelicerata
- Class: Arachnida
- Order: Araneae
- Family: Theridiidae
- Genus: Latrodectus
- Species: 31
Among the different species of black widow spiders, three are indigenous to the United States: the western black widow (Latrodectus hesperus), the southern black widow (Latrodectus mactans), and the northern black widow (Latrodectus variolus).
1. Western Black Widow Spider
Latrodectus hesperus, or the western black widow spider, resides in the western areas of North America. This spider is most commonly near the Canada-US border and less commonly in the Canadian Prairies in Western Canada.
Female western black widow spiders measure 14-16 millimeters (1/2 inches) in body length. They have the typical appearance of the black widow spider, but their hourglass mark is sometimes yellow or, on rare occasions, color white. Males are about half the females’ size and are tan-colored with lighter striping on their abdomen.
Female western widows stimulate through contact with the males’ webs. Each produces sexually specific scents combined with their silk. Both respond through the initiation of mating when they come in contact with each other’s web. The males can breed several times within their relatively brief life span, showing a preference for well-fed mates to avoid getting eaten.
2. Southern Black Widow Spider
The southern black widow (Latrodectus mactans) is native to the southeastern regions of the United States. Their range reaches as far to the north as Ohio and as far to the west as Texas.
Also known as the shoe-button spider, female southern widows have a body length of 8-13 millimeters (0.31-0.51 inches). Egg-carrying (gravid) females also have abdomens with diameters of more than 1.25 centimeters (0.5 inches).
Females usually look like the typical black widow, but many of them also have a red or orange patch above the spinnerets on top of their abdomen. These female southern widow spiders have a life span of up to three years.
Male southern black widows are only 3-6 millimeters (0.12-0.24 inches) in body length. They either appear purple or similar to southern black widow babies, have a grayish to black abdomen with a white stripe across, spotted with orange and yellow. Male southern widows have a life span of around 3 to 4 months.
3. Northern Black Widow Spider
Latrodectus variolus, which is called the northern black widow spider, is typically located in the Middle Atlantic states of the United States. These states include New Jersey, Delaware, and Maryland.
This spider can also travel as far north as Massachusetts during the April-May mating season and can be found in Connecticut during late summer.
On rare occasions, they reside in the southern parts of Ontario and Quebec in Canada and southeastern Michigan.
While they possess the usual physical characteristics of a black widow, female northern black widow spiders have a different hourglass mark on their abdomen’s underside. This mark appears ‘broken’ or split in the middle. Aside from this distinction, they also have a row of red spots along the upper midline of their abdomen.
Other females, particularly the younger ones, have a series of diagonal white stripes on each side of the abdomen. Males and immature spiderlings only have four white stripes on each side of their abdomen.
Black Widow Spiders from Around the World
Latrodectus apicalis, the Galapagos black widow, is native to the Galapagos Islands. Like most black widow spiders, it has a red or orange hourglass marking on its abdomen’s ventral side. From the Lesser Antilles and South America, Latrodectus curacaviensis also has an hourglass mark. But it is distinguished by a black diamond shape and four red triangles in a square.
Some black widow spiders have even more unique markings. Originating in South Australia, Latrodectus hasselti, the Australian black widow (also known as the redback spider), has a red or orange longitudinal stripe on the dorsal surface of its abdomen. It also has a scarlet hourglass-shaped streak on its ventral surface.
Hailing from the Mediterranean region, Latrodectus tredecimguttatus, known as the Mediterranean or European black widow, is characterized by 13 spots situated on the upper surface of its abdomen. They are usually red-colored but also appear yellow or orange.
Conclusion – Black Widow Baby Spider
So, to recap, what do baby black widow spiders look like? At the start of the maturation period, a black widow baby has a white and metallic mahogany hue with a stripe in the middle and diagonal streaks on its sides. In this phase, they are very tiny, no bigger than the head of a pin. They also have underdeveloped fangs and are without enough venom, which means they are practically harmless.
It’s no wonder that the black widow has always been a source of fear among people. It seems that even from birth, baby black widow spiders have been bred to become deadly, brutal, and aggressive predators. But they only do what they have to to survive.
Also, they never really attack humans unless they are provoked. Misunderstood though they may be, it’s still better for us to stay on the side of caution and just look, but don’t touch. Their vibrant and colorful markings are belying their venomous nature.