I used to work at Fireborn Studios, a pottery studio in the Southside of Pittsburgh. Part of my job was packing and shipping pottery to wholesale accounts. The packing area was in the basement, a typical cobwebby, dusty, albeit dry basement with no windows. I would occasionally….okay, OFTEN get distracted by the bugs that would appear when I was moving materials around. One day, I noticed a small, brown spider moving slowly and delicately across the floor. Even from where I was standing, I could see that it had an unusually large head, nearly as high and round as its abdomen. I caught it and took it home to ID and was very excited to discover I had caught a female spitting spider!
Spitting spiders are in the spider family Scytodidae. There are 7 known species found north of Mexico. This particular spitting spider was Scytodes thoracica, a common, widespread spider that has been introduced world wide. S. thoracica may be the only spitting spider found in Western PA. The other species are found in more tropical regions of the US. What’s cool about spitting spiders is that they spit a mixture of venom and glue from their fangs to pin wandering prey. Their heads are large, and domed shaped to accommodate their specialized venom/glue glands. While most spiders have 8 eyes, spitting spiders have 6. They usually have a spotted pattern, are slow in movement, and have thin, smooth legs (not spiny). And they are harmless!
S. thoracica is a small spider, ~5mm from head to end of abdomen, so they’re most likely gluing small insects and other small spiders. I absolutely loved observing this spider! Watching it glue its prey was fascinating! I fed her small crickets. This spider does not make a capture web. They hunt. The spitting spider would approach the cricket ever so cautiously with its thin, front legs tapping forward. Once it would get a few centimeters away, the spider’s body would jerk and suddenly the cricket would be stuck! It happened so quickly, I couldn’t even see it. At most I could make out clear zig- zags of silk-glue if I angled the lighting right. The glue covered the area of a dime. Once the cricket was pinned, the spider would approach and feed.
I eventually found a male spider in the packing area and they successfully mated. I released the male back into the basement to ensure that MORE spitting spiders could be found if I needed one (the owners of the pottery studio were totally cool with it). Not long after mating, the female laid eggs which were loosely bound by a few strands of silk. It looks like spitting spiders carry their egg sacs with their fangs, but according to W.S Bristowe in his book, The World of Spiders, the egg sac is held with the palps backed up with a thread of silk attached to the spinnerets. They can still eat while they carry the egg sac.
Unfortunately, the eggs never hatched. She discarded the sac one day and they turned into a yellow, infertile clump. I was bummed out that I wasn’t able to witness the life cycle. The mama spider wouldn’t eat after that, I’m not sure why. I offered her fruit flies and she seemed to ignore them. I offered a freshly killed cricket and she wouldn’t accept. Months went by and I didn’t see her eat. Finally, she died.
About 2 years later, in preparation for a spider presentation at the Outdoor Classroom south of Pittsburgh, I contacted the pottery studio owners to see if I could crawl around their basement to specifically find a spitting spider. I believe it took under an hour, but I did find a female (I gotta wonder if I knew her dad)! It was so cool to have a live specimen while I talked about spitting spiders to the audience. Spitting spiders can live a bit longer than the average spider at two to three years so I had that one for awhile. She is now preserved in alcohol, RIP.
I’ve never seen spitting spiders anywhere else except in my old, brick house in the South Hills. I lived in that house for 10 years and knew every spider that crossed the threshold. One day, a spiting spider and a cobweb spider (AKA house spider) were having a standoff in the entryway. The spitting spider was cruisin along on the ground and had triggered the web of the cobweb spider. The cobweb weaver responded by rushing towards the vibration only to be spit at! The cobweb spider would struggle and then the spitting spider would start to approach but would get tangled in the cobweb and then the cobweb weaver would respond. It went back n forth until I finally separated them. I let the spitting spider go in the house because I was hoping where there’s one…! I would have my very own spitting spider population in the house! Alas, that was the one and only time I ever did see a spitting spider in that house. I’ve since moved.
I did visit the pottery studio about a year ago (to actually make some pottery!) and couldn’t help but check the basement while I was there. I did see a spitting spider molt, but I did not find a live spider. Fast forward to this past April. I was visiting family in Beverly Hills, Florida. Their house is in a suburban neighborhood with a lot of pines and oaks. Of COURSE I went spider hunting with high hopes of finding the rock star spiders of my bucket list (bolas spider, ogre-faced spider, trap door). No such luck, but I DID find a spitting spider in the woods! I was digging away at a rotting tree stump and just caught a glimpse of thin, delicate legs. I would carefully pull more humus away just to see the spider hide itself deeper. I eventually caught it and was surprised at how large (~8mm) and dark it was! This specimen was NOT the Scytodes thoracica I was used to seeing in Pittsburgh! In fact, I’m not sure what I have. I did a little research and it could be Scytodes fusca, but I’m not even 75% sure.
About a month later, the Florida spitting spider produced an egg sac and seemed to carry it forever (month and a half?). The eggs were viable and the spiderlings hatched. There were at least 45 babies all huddled together in a cloud at the corner of the container. About 2 weeks later, I separated some, but not all of them, into small vials.
They are eating and growing! I hope to have at least one to carry on as a pet for presentations. These spiders are common, but elusive. They usually hunt by walking around, although the Florida spiders have built meshy webs. If you happen to see one, consider yourself lucky! Look for the high-domed head and those long, delicate legs. They are completely harmless to humans, so get up close and put an ant in its path; see what happens!
Interesting. I’d never heard of spitting spiders before. There is apparently at least one species (Scytodes thoracica) which lives in the area I live, S.France, and furthermore, I recognise the critter—judging by the photographs I’ve found on the web. I’ve seen some outside in the garden where I used to live, where there were certainly plenty of insect munchies. (And hedgehogs. Not quite hedgehog grand central station, but they always seemed to be about.) In any case, I had no idea that spider spat.
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