Brown Widow - beginner seeking advice!

[Cbella]

Hello!

I am a total noob with arachnids and currently have a brown widow in a (excuse layman terminology) ‘good-sized plastic terrarium’. She seems very happy in there, we have had her for a few months now. I just cannot find much information out there about keeping them as pets, it’s all been quite trial and error. She has just laid a second egg sac in the tank, yet hasn’t been exposed to another male brown widow while we have had her. Would there be babies in there? Or is it hollow? I had introduced another spider (false wolf) to the environment (now realizing my mistake!) and she immediately went after it and killed it. I know I must sound like a total moron but, it’s not possible she mated with that spider is it? Interbreeding?!

Excuse the waffling information, literally ANY and ALL information anyone has on these amazing spiders would be hugely appreciated.

Many many thanks if u made it this far!

 

[Albireo Wulfbooper]

No, it's not possible for a wolf spider to impregnate a widow spider. If the female mated before you captured her, and hasn't moulted since, she could have been storing sperm. Some spiders also can make egg sacs that aren't fertilized but I don't know if Latrodectus species are among them.

 

[chanda]

Brown widows are super easy to keep in captivity. All they need is something they can attach their webbing to - and food. When I've kept them, I just stick one in a large deli cup with a ventilated lid (just pinholes), throw in some dry twigs as attachment points for webbing, and drop in a cricket for her to eat roughly once a week or so.

As for those egg sacs... Did you catch her as an adult? Or has she molted in your care? If you caught her as an adult, there is a very good chance that she has already mated and those egg sacs could be fertile. Female spiders retain sperm in special structures called spermathecae, them use it to fertilize their egg sacs weeks or months later. They can lay multiple fertile egg sacs from a single mating. I've had black widows lay up to seven or eight fertile sacs in captivity, without a male in sight. If, on the other hand, she has molted in your care, then the eggs will not be fertile. When an insect or spider molts, it sheds not only the exterior cuticle (the "skin") but also the linings of a number of internal structures, including tracheae, the sucking stomach, - and the spermatheca. Any retained sperm are discarded during the molting process.

She definitely did not mate with that false widow spider. While closely related spiders (within the same genus) can sometimes interbreed, a false wolf spider can't mate with a brown widow. Spiders have a weird and complicated way of mating. Instead of mating through direct copulation (where penis is inserted into vagina to deliver sperm) they have to go through a lot of other steps. First, the male spider produces sperm and deposits it on a sperm web, then he takes up the sperm into his palpal bulbs (the swollen "boxing gloves" at the end of his pedipalps) where it is stored until he meets a receptive lady spider. When that happens, after an appropriate courtship ritual (and assuming she doesn't just eat him first), he will insert one of his palpal bulbs into her epigyne, allowing him to deposit sperm into her spermatheca - where she will store it until she's ready to produce eggs, at which point she will use the retained sperm to fertilize her eggs. The shapes and structures of the palpal bulbs and the epigynes of spiders vary considerably from one species to another, so only the palpal bulb of the same species (or sometimes a close relative) will fit into the epigyne of the female - like a key fitting into a lock - allowing the male to deposit sperm into the spermatheca.

Most spiders will lay egg sacs, whether they have mated or not - but if the spider has not mated (or has molted since mating) then the egg sacs will not produce offspring.

One word of caution - if those egg sacs are fertile, once they hatch you will end up with dozens (or hundreds) of baby spiders, and their natural instinct is to disperse. They are incredibly tiny and can fit through all but the tiniest ventilation holes, so unless you want your house to be full of brown widow spiders, you need to either make sure there are no gaps, cracks, or holes they can escape through - or remove the egg sacs. (When I raise black or brown widows, I usually use a pair of long tweezers to pull the egg sacs as they are laid. You can then either destroy the egg sac - or put it safely outside, where the spiders can disperse somewhere other than in your house.)

 

[UraniumEater21]

If you have had it for a few months, you are probably doing a good job of keeping the spider alive. Just feed it a cricket about the size of its abdomen a week or so and you'll do fine.

 

[Cbella]

Wow! Thank you all so so much! I have been trawling the internet for weeks And found nothing so informative! Truly, thank you for taking the time to help

I found her as an adult and am pretty sure she hasn’t shed but I may have missed this. How often do they shed?

The tank is far larger than she needs and I had wanted to introduce other spiders, I had cellar spiders and false wolf spiders but they didn’t fare so well (R.I.P. ) so is it best to leave her alone in there?

also, watering, I copy what a lot of tarantula keepers do on YouTube but I think she likes her water from spray like rain directly on her. When pouring water into her ‘dish’, she goes nuts and runs right towards the stream of water, maybe she thinks it’s prey?

I live in Cyprus, Europe, and haven’t managed to get any crickets for her but go on ‘bug hunts’ to find her food. I have given her a variety of crawling or flying food. Is there anything I should avoid? Any other care information would be super appreciated! I have wood chips and coconut chips as the substrate with wood sticks and rocks but she likes to hide in the top corner of the lid.

any idea how long they live? I have a 5 year old son who will be devastated when she dies (unless I can replace her without him noticing!)

Again, thank you for reading the rambling!

 

[UraniumEater21]

If it is an adult it probably won't molt anymore.

Don't put other spiders in there. They will fight.

Most areaneomorphae, like your brown widow, only live for about 1-2 years.

I hope this answers some of your questions.

 

[chanda]

I found her as an adult and am pretty sure she hasn’t shed but I may have missed this. How often do they shed?

The tank is far larger than she needs and I had wanted to introduce other spiders, I had cellar spiders and false wolf spiders but they didn’t fare so well (R.I.P. ) so is it best to leave her alone in there?

also, watering, I copy what a lot of tarantula keepers do on YouTube but I think she likes her water from spray like rain directly on her. When pouring water into her ‘dish’, she goes nuts and runs right towards the stream of water, maybe she thinks it’s prey?

I live in Cyprus, Europe, and haven’t managed to get any crickets for her but go on ‘bug hunts’ to find her food. I have given her a variety of crawling or flying food. Is there anything I should avoid? Any other care information would be super appreciated! I have wood chips and coconut chips as the substrate with wood sticks and rocks but she likes to hide in the top corner of the lid.

any idea how long they live? I have a 5 year old son who will be devastated when she dies (unless I can replace her without him noticing!)

If she is an adult, she should be done shedding. Long-lived spiders (like tarantulas) will continue molting long past maturity, but shorter-lived spiders like widows typically only molt until they reach maturity. With a good-sized spider, it's hard to miss when they molt because it will suddenly look like you've got a second (but dead) spider hanging in the web, and the actual spider will have increased - sometimes dramatically - in size.

While I can appreciate your desire to maximize your cage space and have other creatures to observe, keep in mind that pretty much anything you put in there is going to be regarded as food by your widow. They are not social spiders, and when you find them in the wild, they do not nest in close proximity to one another. If good spots are in short supply, they may tolerate living relatively close to one another - but at any moment, could decide that the next door neighbor looks pretty tasty.

Honestly, when I have widows, I hardly ever water them at all. They do not have water dishes, but might occasionally get a very light misting on their web. They do not need supplemental water because they meet their moisture requirements from their prey - though given the opportunity, they will sometimes drink from water droplets. They generally do not like water sprayed directly on them - it's better to just lightly mist an unoccupied portion of the web.

It's safest to raise or purchase feeder insects for her, rather than catching your own, if possible, just because with wild-caught insects you never know whether they might have been exposed to pesticides or other chemicals. Pesticides are not always immediately lethal, so just because the bug is running around does not mean it has not been exposed. Sometimes a bug might consume a sub-lethal dose that over time (and repeated exposure) could accumulate to fatal levels. Other pesticides are intentionally slow-acting, so the bugs (like ants) can take them back to the colony, so the entire colony is killed, not just the individual ant. Some pesticides contain growth regulators that act by impairing the ability of an insect to develop, molt, and reproduce. I don't know what effect these would have on a spider, since they are targeted toward pest insects like cockroaches and fleas - but I wouldn't take the risk with my own pets.

My own experience with both Latrodectus and Loxosceles has also been that they prefer hiding at the top of the lid, which is why I use "feeding ports" (basically, a hole cut in the lid, with a sponge stuffed into the hole) so I can drop in feeder crickets without having to remove the entire lid. This helps to prevent escapes - and prevents the spider accidentally getting a leg pinched in the lid and damaged or broken off when re-closing the container.

As for life span, it's usually only around one to two years from hatching to death. If your spider is already mature and laying eggs, she's well on her way. Her remaining lifespan is likely less than a year - and could even be as short as a few months. While you could try to fool your son with a replacement spider, kids can be surprisingly observant. He might not be fooled by the replacement - unless you can slip in one that has recently molted, and try to pass any differences in size or appearance off as being due to the molt. It might be better to simply explain that spiders don't live as long as people, so he is prepared for her death when it comes - and if you have a new spider (or even some of her offspring) that would help to cushion the blow. Perhaps the two of you could sit down and watch or read Charlotte's Web together and talk about the natural life cycle of spiders and other animals.

I teach children about bugs and spiders, and while they are always sad when one dies, I've found that kids as young as five or six are generally able to accept the loss and move on - particularly when it's due to natural aging. They do sometimes get a little more upset when it's premature - like when the caterpillar they've been raising turns out to be infected with a virus or parasitic fly larvae, and fails to pupate or dies in the chrysalis. But even then, they get over it pretty quickly.

 

[Cbella]

A thousand thank yous to you guys for all this help!

Chanda, the tip on reading Charlotte’s Web is absolutely genius

 

[pannaking22]

You've kept yours alive longer than I've kept any of mine lol. I have no problem with any of the other widows, but for some reason I can't keep geos alive. Weirdest thing.

 

[Cbella]

I wish I could say I knew why! Beginners luck!