The Black Widow Spider – Latrodectus spp. Authored by Elle Mactans
Widow Spider Captive Care
Latrodectus are a genus of true spiders in the family Theridiidae, most commonly known as the widow spider, or button spiders (other names include hourglass spider, rod spider, cherry spider, black wolf, shoebutton spider, and jockey spider). There currently 32 recognized species worldwide, found on every continent except Antarctica, with six species found in North America alone (geometricus, mactans, hesperus, various, and bishopi).
DESCRIPTION & BEHAVIOR:
Adult female widows are known by a usually black or brown body color with a bulbous abdomen, and a red or orange hourglass on the ventral side. The exact pattern of the hourglass varies individually, and is not always necessarily indicative of species. It may appear as one or two smushed rectangles, two red dots, a line or bar, disconnected in the middle, faded or missing bottom half, or may be missing altogether. The abdomen of an adult female can have dorsal patterns, stripes or dots, of varying amounts of red, orange, and/or white. Juveniles and mature males are about half the size of an adult female, and are often more of a light brown color, with very colorful patterns, and a white or orange hourglass. Chances of sexual cannibalism after mating are high among some species of Latrodectus, rightfully earning them their common name “widow spider”.
Widow spiders can be found hanging upside down in their messy-looking webs of very thick, strong silk. Latrodectus are a very hearty genus and can be found virtually anywhere – abandoned cars, toys, or farm equipment sitting outside; sheds; garages; outdoor water heater sheds; wood piles, etc. Also occupying in the same areas and ranges are Steatoda sp., the false widow spider. They look almost identical, minus the hourglass, but their venom is not as potent. With all spiders, temperament does vary by the individual; however Latrodectus seem to be most docile when they are small, gradually becoming more defensive as they grow larger, with females protecting an eggsac obviously displaying the most defensive behavior.
Black widow spiders have come to be greatly feared by most, made out to be aggressive, deadly animals no thanks to the media and the spread of misinformation. In reality, widows are a very shy, almost docile spider, with only a handful of recorded deaths worldwide. The illness or symptoms produced by a bite is called “latrodectism”. All spiders can choose how much, if any, venom is injected during a bite. If no venom was injected, it’s called a “dry bite”, and there are no symptoms. About three-quarters of all “wet bites” from a Latrodectus contain little venom and will cause no more than pain at the site of the bite. Symptoms of a large dose of venom include severe sweating and quickened pulse, muscle pain, headaches, stomach cramps, and nausea/vomiting. Symptoms usually continue for several days. If left untreated, they may persist for up to several weeks or months. Treatment for latrodectism includes pain killers, muscle relaxers, and, in severe cases, antivenin.
Latrodectus are very easy to keep, and like other spiders they do not require much attention or feeding. An adult female can be kept in a 15-30 oz plastic jar with plenty of small air holes poked into the sides. I like to reuse old food containers – the plastic jars from the grocery store that rice comes in are perfect. I provide a very thin layer of dry substrate or soil on the floor of the enclosure to soak up any smells from old prey (unlike tarantulas, I leave the prey in my Latrodectus enclosures; I’ve found that they’ll go back to them every so often for a little snack between monthly feedings). Add a few sticks or a couples small pieces of bark and the enclosure is ready. Humidity levels vary depending on species – I try to mimic the natural environment from which they come (for example, L. bishopi from Florida are kept more humid than L. hesperus from Arizona).
Wild caught females tend to often be gravid, so expect plenty of egg sacs – a female can keep producing sacs from one mating until they either molt or die (I had one female L. mactans produce 11 sacs within a 12-month period before dying). The eggsac itself is small, off-white or yellowish, and it takes about four weeks for spiderlings to emerge (give or take, depending on conditions). At about the 3-week mark, the sac will darken to a light tan color; this indicates that the spiderlings are about ready to emerge. Up to 500 slings (spiderlings) can be expected, but the sacs I’ve worked with have only yielded upwards of 200. There are a few ways to deal with an egg sac if you plan on keeping it and raising the slings. If possible, remove the sac before the slings emerge so you don’t have to work around momma. Any container will do, I go for a 12 oz food container (make sure there are no air holes). Once they emerge, I like to cull the numbers by leaving them together for a couple of weeks. They will cannibalize each other but I also like to provide prekilled prey – a few small roaches or crickets will do – so they grow more quickly (plus it’s pretty cute watching a bunch of baby widows feed communally on a large prey item). Once members are at a manageable level, you’ll need a bunch of small vials or little deli cups set up in a room with good lighting (if you like, you can put a small stick in the container to give them something to web to), a sheet of white paper, and a chopstick or something thin and pointy. Several vials or deli cups need to be set up, as the slings will have, at this point, webbed to the top of their container and will be ready to scatter when the lid is opened – work quickly. Crack or open the lid of the container and use the chopstick (or whatever) to snag a bit of webbing. Several slings will come off at one time, so be prepared to tap them into the vials or cups. Spiderlings can be fed adult cricket legs, roach nymphs, or pinhead crickets on a weekly or bi-weekly basis.
I was not able to find meanings for every known species of Latrodectus, but what I could find is listed below. Many of the names relate to the species-specific dorsal patterns and/or colors.
Latrodectus (greek) means “biting in secret”, in reference to the fact that their bite often goes undetected until symptoms appear.
apicalis: apex, summit
curacaviensis: Curacaví, central Chile
dahli: named after the arachnologist Friedrich Dahl
diaguita: derives from “tiac-y-ta” and means “village inhabitant” in the extinct language Kakan or Cacán of the Calchaqui tribe
erythromelas: unsure of meaning, but the species name is shared with several other animals with red and black coloring
geometricus: “geometric”? Original intended meaning unknown because Koch didn’t bother to write it in his original description
hasselti: back/red back
hesperus: the planet Venus
indistinctus: indistinct, not clearly marked
karrooensis: Karoo/Karroo, South Africa
katipo: the night stinger
mactans: sacrifice, slaughter, or destroy
mirabilis: amazing, wonderful, remarkable
obscurior: dark/secret; vague/obscure
pallidus: pale, ashen
quartus: fourth, or born fourth. Could have been named for the Greek Christian Quartus, from the first century; one of the seventy disciples who converted many to Christianity
rhodesiensis: Rhodes (island), Greece
thoracicus: a breast-plate, on the chest
tredecimguttatus: thirteen spots/speckles (used to be considered a subspecies of L. mactans)
variegatus: variegate – to diversify in external appearance especially with different colors