#scytodes

[platycryptus]

Spitting spider (Scytodes alayoi) guarding her small clutch of eggs under a palm frond

(Florida, 1/24/25)

[onenicebugperday]

@usoppisking​ submitted: Hey! My friend found this little cute friend in her house here in Buenos Aires. It's definitely from the pholcidae species but I can't found it's name 🥲 hope you know! And hope you're having a nice week!

Hi! It is not Pholcidae, actually! It’s a spitting spider. Most likely Scytodes univittata, I think.

[bugsicles]

Spooky Season Special: The Spitting Spider

In honor of the month of October, a post about one of the creepiest crawlies I've crossed paths with thus far

First off is a spider with a giant pumpkin head and jack-o-lantern face: the spitting spider (Family: Scytodidae).

This unique spider goes about catching prey in an unusual way - instead of constructing a web spun with silk from the spinnerets on its abdomen and waiting for a catch, it roams for its favorite food - other spiders - and once within firing range it shoots a gluey, silky net from its mouth to pin the prospective meal to the ground. It then proceeds to envenomate the restrained victim and wrap it with spinneret silk in more typical spider fashion. Their web-like spit projections, enlarged heads, and unusual eye arrangement distinguish these prowling night-time hunters. And given that they enjoy indoor living and are common in the U.S., there's a pretty good chance that one is haunting your household as we speak.

Figure 18.1, Suter & Stratton (2013)

In a way these spiders have re-invented silk, for while they produce conventional spider's silk in their abdomen, they also figured out how to make a functionally similar substance in their mouths. The friend in the photographs above has such a rotund 'head' precisely because of its saliva-generating needs. The cephalothorax houses the enlarged spit glands, which feed through the chelicerae (the two mustache-like appendages in front of the mouth), at the end of which sit the fangs (see below). Some of these glands produce venom, and some produce the fibrous net material and sticky substance that is squirted from the fangs when attacking prey (or attempting to dissuade a predator with a web pie to the face). Whether the net is laced with venom seems to be up for debate in the literature. Streams from the 2 fangs make an alternating zig-zag pattern, and this woven mesh contracts after it is fired, often pinning the quarry's legs to its body, in addition to binding the creature to the floor.

Chelicerae (a) and fangs (b) of a spitting spider (Figure 18.4, Suter and Stratton 2013).

It takes the spitting spider ~20 milliseconds to generate ~2 feet of silky string, oscillating its fangs at ~1000 wiggles per second to weave its net in midair. And it looks as cool as you would hope it would - videos from the first author of a great book chapter I found, from which much of this information is sourced, can be found here. The chapter, "Predation by Spitting Spiders: Elaborate Venom Gland, Intricate Delivery System" by Robert Suter & Gail Stratton, is very accessible and contains lots more awesome information about these spiders (read here).

Videos by Robert Suter

According to the authors, muscle-driven oscillations greater than ~500 cycles per second are rare in nature, given the time it takes for muscles to relax between contractions. So it seems unlikely that the spider is able to wiggle its chelicerae so fast on its own. Higher frequencies are possible when things other than muscles are driving the cycles, and in this case the authors suspect that the fang-silk system is behaving the way a water hose does when turned up all the way with its end free to lash around. The silk-glue is forced out of the fangs so fast that they jiggle in response, with a frequency determined by their mass and the elasticity of the connective tissue of the chelicerae. The relatively small fangs of this spider may be that way since they allow quicker oscillations for a more tightly woven mesh trap (though the authors note some conflicting evidence, including the fact that the larger fangs of some species in the group do not appear to wiggle more slowly than others). Regardless, this is all I'm going to think about when I use a hose now.

I had never heard of spitting spiders before coming across this individual in my home the other night, and I suspect the same is true for most people, which is surprising given how common and rad they are. There doesn't seem to be any end to the fascinating goings-on right under foot!

Sources:

Suter, Robert & Stratton, Gail. (2013). Predation by Spitting Spiders: Elaborate Venom Gland, Intricate Delivery System. 10.1007/978-3-642-33989-9_18. https://www.researchgate.net/publication/268069024_Predation_by_Spitting_Spiders_Elaborate_Venom_Gland_Intricate_Delivery_System

Spider. Encyclopaedia Britannica. https://www.britannica.com/animal/spider-arachnid

bugsicles is a blog about the bugs I find in my backyard in southern New Mexico. I don't use any special equipment beyond a cheap jeweler's loupe and a phone camera, and occasionally an amateur microscope.

[drhoz]

#1555 - Scytodes thoracica - Spitting Spider

A fairly frequently ID request - this particular individual was photographed by Garin Taylor, who’d managed to ID it himself but his photos show the six eyes and unusual shape so nicely that I couldn’t resist.

The species is so easily spread by human activity that it’s not entirely sure where it originated. It’s found in Europe, North Africa, Turkey, temperate Asia to China, Korea, Japan, and now introduced to North America, Argentina, India, Australia, New Zealand. 

The most noteworthy aspect of the spider is what gives it it’s common name - silk glands connected to the venom glands in it’s cephalothorax. After sneaking up on prey and testing the range with a foreleg, the spider sprays venomous silk from it’s fangs in a zig-zag pattern, in 1/700th of a second. 

The mother makes a nursery web for her emerged spiderlings, and carries her eggs under her belly in a net of silk.

[onenicebugperday]

@misanthropiczombie submitted: Found a nice shower friendo today. I've got a strict personal space rule, however, so he went to bottle prison and was let go outside a short whole ago. Think you can ID from this photo? [Redact please] [removed] area.

He'd probably reach the edges of a half dollar coin with all he leggies stretched out, and his abdomen was somewhere between the head of a pin and a qtip. This is very zoomed in so he looks much bigger than he is.

Very rude of them to visit your shower without asking permission. Still, a very cute and leggy friend! They’re a spitting spider in the genus Scytodes, but don’t worry, they don’t spit at people, only at potential prey.

Also, you submitted this as an ask and I cannot remove locations from asks, so I’ve re-posted it. In the future, please send photos using the submit page rather than the ask page. Thank you!

[dinophotography]

[archisb-blog]

Emblem #scytodes #spider #spiders #pelegrina #camo #camouflage #camoflauge #arthropods #arachnida #samsung #samsungs9plus #shotsoftheday #shotonsamsung #shotonsamsungs9plus (at Vile Parle East) https://www.instagram.com/p/CEZAR4pj1aL/?igshid=4y26teodezbp

[drhoz]

I’d have preferred a less exploitative, over-sensationalised video, but there were surprisingly  few options