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Nature and Wild Life

Steatoda triangulosa

I found this little guy under my drawers while I was doing some cleaning around my room. Though it could be easy to mistake this particular spider for a Brown Widow (Latrodectus geometricus ), it is in fact a Triangulate Cobweb Spider (Steatoda triangulosa). I mean, they aren’t even in the same genus though they are from the same family (Theridiidae) of Cobweb spiders like your Widows and so forth. Unlike spiders from the genus Latrodectus, Steatoda spiders are generally harmless though they do share the same neurotoxin as other widows though it seems like it’s very rare for humans to even get a bite from a Cobweb spider (since their fangs are probably too small to even break skin). With that said, I still wouldn’t recommend handling one though some people do it anyways. They are generally found in Eurasia and North America so it’s no surprise that I was able to find one though they are considered an invasive (though naturalized) species since it was probably originally a species from Southern Europe. You’ll usually find them in dark places around your house.

As scary as they might seem, they are actually kind of beneficial to have around your house (despite being an invasive species). Especially considering they prey on anything that is unlucky enough to come across its silk web. This could be anything from small isopods, roaches, other spiders, and even ants. Suffice to say, for an invasive species, they are pretty good at taking care of other invasive species that happen to infest your home.

Now normally, I don’t recommend taking local wildlife into captivity, I made an exception to this particular spider because it’s an invasive species anyways and seems to be in it’s later stage of life anyways (I believe this one is a female since it has the larger abdomen and the males are known to be much smaller ). It seems like true spiders (Araneomorphae) unlike Mygalomorphae (Tarantulas, Funnel Web spiders, Trap door spiders,) tend to live shorter lives in general. Usually around a couple of months up to a year at most. Sometimes a couple of years if they are really lucky. This female that I found happened to have an egg sac in it’s web too. It would be interesting to see if I could raise this spider alongside some of these soon to be spiderlings and maybe potentially release them somewhere where they can do a little bit of pest control around my house. For now, it’s just this female triangulate cobweb spider.

My enclosure is more tall than it is wide. It’s one of those plastic food containers you can get at your local supermarket. I punched some ventilation holes on the top sides of the enclosure and on the lid to provide some ventilation. I made sure the holes weren’t large enough for the spider or her prey to escape though I will have to check to see if they aren’t too big for the spiderlings when they eventually hatch. My enclosure consist of some the same substrate that my tarantula (and eventually my Dubia roaches) has which is a mix of creature soil (cheap substrate you can buy which is a mix of peat moss, soil, sand, and carbon) and coco fiber. Though this species seems to like dark and potentially dry areas, a little bit of humid retaining soil wouldn’t hurt and I had some left over substrate anyways so I figured it might be fine for this little spider. Besides, I kept the substrate level pretty low compared to what I would use for a more terrestrial species. What really matters here is places for webbing and that’s where the whole elevation aspect of the enclosure matters to this species. I used some fake plants to provide areas where the spider can hide under and build webs to catch any prey that will fall onto it. For the most part, I’ve been feeding this spider isopods that I have found roaming around since I noticed there were some dead isopods in this spiders original web under my desk so It made sense that this spider was accustomed to eating them already. I’ve also had some success over the past week feeding flies to this spider by using the enclosure as a fly catcher since the enclosure is small enough to be carried around anyways. Generally, this spider will web up whatever gets trapped in her web and most likely injects venom into the prey and saves it for later whenever the spider gets hungry. At the very least, this spider is going to be fed at least once a week, sometimes every other week depending on the size of the spiders abdomen. You usually don’t want to overfed a spider, especially one that doesn’t really move around that much. It’s also assumed that these spiders get their hydration from the prey they eat so there’s no need to place any water bowls or spray the enclosure. I found this spider under my drawers and that area isn’t really a place I would call humid by any means.

So that’s what I got so far in terms of husbandry for this species. It’ll probably be sometime before these spiderlings will hatch or perhaps the mother will pass away due to old age. It’s hard to say but I’ll continue to do more research into this spider as I observe it.

Update: April 19: Spider Behbehs

So the babies (spiderlings) had finally hatched. You can see there's dozens of them on the mother's web (who's still alive btw). I think my next plan after observing them for a day or two is to make sure there isn't any canibalism going on. While that's a natural part of their life, I want to spare as many spiderlings as I can before letting them go. Usually, they be fine for a few days but it's honestly better to eventually allow them to leave their home web and make their own somewhere else. I might let them go somewhere like a window or specific areas where the chances of catching prey are more likely. Natural pest control or what have you. I might even let the mother go too even though she's got a nice web constructed in my enclosure. In the meantime, there are various prey items such as an Ant I found wandering in my room which I used to feed the mother and she seemed to had devoured it without too much issue. There's also some webbed up isopods sinces that's what the mother was originally eating when I first found her so I might as well include that as a staple diet.

Update: Late April

At the time of this post, I'd had released the mother spider alongisde the spiderlings in an nice shaded spot under the shade of plant located in front of my house. That way, they'll have a higher probability of catching some pest inverts and maybe snatch a few isopods which seem to be numerous with all the rain I've been having. Really glad this husbandry experiment worked out really well.

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