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Wildlife Wednesday – Along Came a Spider As December arrives with the Stygian blackness of its early nightfalls, it seems like the perfect time to meet a creature for Wildlife Wednesday that’s perfectly at home in that environment. On December 4, at 10 a.m., join us at Jesse Jones Park & Nature Center’s Wildlife Center to meet Natasha, our ambassador Southern Black Widow.
Named for Natasha Romanoff of The Avengers movies, Jesse Jones Park’s special Wildlife Wednesday guest -- Natasha -- is a Southern Black Widow (Latrodectus mactans). She IS venomous. The venom is neurotoxic and referred to as a latrotoxin.
The venom can cause pain and other symptoms but is rarely fatal to healthy humans. Deaths in healthy adults from Latrodectus bites are exceedingly rare, with no deaths despite 2,000 bites yearly, and studies within the past several decades have been unable to confirm any fatalities from this or any of the other U.S. species of Latrodectus (e.g. zero fatalities among 23,409 documented Latrodectus bites from 2000 through 2008).
The females are well known for their distinctive black and red coloring and for the fact that they will occasionally eat their mates after reproduction. The body length (excluding legs) of the mature female is 8–13 mm (0.31–0.51 in), and 3–6 mm (0.12–0.24 in) for males. Legs are long in proportion to body. Females are shiny and black in color, with a red marking in the shape of an hourglass on the ventral (under) side of her very rounded abdomen. There is much variation in female size, particularly in egg-carrying (gravid) females. Many female widows also have an orange or red patch just above the spinnerets on the top of the abdomen. Juveniles have a distinctly different appearance from the adults; the abdomen is grayish to black with white stripes running across it and is spotted with yellow and orange. Males are either purple, or closer to the appearance of the juveniles in color.
There are four species of widow spiders in Texas: Latrodectus mactans (Southern Black Widow), Latrodectus variolus (Northern Black Widow), Latrodectus hesperus (Western Black Widow) and Latrodectus geometricus (Brown widow). The Latin name Latrodectus mactans translates into “murderous biting robber.” These species are native to North America.
Black widow spiders typically prey on a variety of insects, with a preference for fire ants if extant, but they also feed on woodlice, diplopods, and chilopods when they are young, and occasionally other arachnids. The spider's web is even strong enough to catch animals as large as mice. When the prey is entangled by the web, Latrodectus mactans quickly comes out of its retreat, wraps the prey securely in its strong web, then bites and envenoms its prey. The venom takes about ten minutes to take effect. In the meantime, the prey is held tightly by the spider. When movements of the prey cease, digestive enzymes are released into the wound. The black widow spider then carries its prey back to its retreat before feeding.
A female black widow spider like Natasha can produce four to nine egg sacs in one summer, each containing about 100–400 eggs. Usually, eggs incubate for 20 to 30 days. It is rare for more than 100 to survive this process. On average, 30 will survive through the first molting due to cannibalism, lack of food, and/or lack of proper shelter. It takes two to four months for black widow spiders to mature enough to breed; however, full maturation typically takes six to nine months. The females can live for up to three years, while a male's lifespan is about three to four months. The female may eat the male after mating.
The widow spiders are among the most recognized spiders on earth; they are the largest of the cobweb weavers, family Theridiidae, and all species are venomous. The web of the black widow spider is a three-dimensional tangled cobweb of exceptionally strong silk. The term widow spider originated from the idea that the females devour the males after, or during, mating. This mate devouring behavior is somewhat a myth; while it may occur in captive situations, where the male cannot escape, it is uncommon in the field. Widow spiders build strong, sloppy webs, in which the females usually remain, hanging upside down most of the time. Like most widow spiders, it prefers dark, cool places to build its web, such as outhouses, window wells, under well covers, and beneath trash.
Female widow spiders are bulbous and shiny in appearance and may have bodies 12-16 mm long. Males are much smaller than the females, with longer legs; they are so different in appearance than females, that they are rarely recognized as widow spiders by the average person; males are not considered a threat to humans, although they do possess venom and can bite. Juvenile widow spiders are usually light colored, and darken to their adult coloration gradually, with each successive molt of their exoskeleton.
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20634 Kenswick Dr, Humble, TX, United States, Texas 77338
