Sphodros (purseweb spiders)

[aaarg]

cool spiders. i recall spending plenty of time searching for them many years ago, in vain -- and until july of this year, i had only ever seen a single sphodros web. since july of this year, i've spotted four webs - plus i saw a male sphodros rufipes, and found piece of an exuvia outside of a web. i've attached photos of three webs along with the male and the impressive fang.

i was surprised to see that two of the webs i found were not attached to the base of a tree, but rather low vegetation. kinda just in a clump of 'grass' along the edge of paths. i kinda just assume these are sphodros rufipes, but iNat hasn't provided much insight.
the fourth web, not photographed, i presume belongs to a sphodros niger - which doesn't build its web up, it lays hidden, draped across the ground near the base of a tree. the exuvia was found next to that web.

the spider attacks prey from within that sock-like web, piercing through the web and into the hapless insect that happened to walk across it. the tube attaches to a burrow in which the spider stays, similar to their mygalomorph kin (trapdoor spiders, folding-door spiders, etc).

i had a summer of sphodros, apparently. just the other day there was a male ummidia trapdoor spider outside of my work. i guess the mygals are calling for me...

(btw i live in northern virginia, us, all these sightings are ~35 miles from DC)

ANYWAY, do we have any atypidae experts here? any insight on these intriguing friends?

 

[Biollantefan54]

Very cool, I’ve I my seen them from one park here in NC. Do you have images are the larger habitat? Any water nearby?

 

[aaarg]

none of them were particularly close to water, the nearest stream at least a few hundred feet away.
one was in a loblolly pine stand, the others were in hardwood forest (actually according to the park website, it's 'acidic oak-hickory forest' - it's a lot drier than most of the woods around here)

 

[RezonantVoid]

The web structure in the grass reminds me moreso of some of prowling spider webs I get around me all the way down in Australia. I'm unsure about wild Sphodros behaviour, but my understanding is they always choose more permanent structures to burrow against. If it is indeed the species that chooses grassy areas (bare in mind those chelicerae could also be the remains of a male eaten by a potentially different species living in the web structure), that would quite the cool find

 

[aaarg]

i haven't been able to find anything suggesting that Sphodros builds webs in grass (though at least one source notes S. rufipes seems to have a preference for smaller trees at their study site). i've posted about my purseweb-in-grass observation in multiple communities, but so far this is the only one to get any responses lol

i don't know what other spiders would build such a web.
i think the first web in the OP was new when i found it, less than a week after an adjacent old field was mowed. i was tempted to flag it so it was easier to keep an eye on, but sure enough i lost it in the long grass (and may have since lost it to a park lawnmower).

the web on the tree in the OP is along a path i walk regularly, and i often wonder if i could tease the spider to attack a tuning fork...

 

[aaarg]

another shot of the chelicerae, showing off the cool Atypid endite

i found two crummy photos of the other web i referred to, the one draped across the forest floor. i believe i noticed this one after a few rainy/stormy days washed away some stuff off the forest floor (at first i assumed this web was damaged and torn from the nearby tree, but the burrow is several inches away from the tree...). the spider chunk was found near the top of this web on another day.

 

[Biollantefan54]

i haven't been able to find anything suggesting that Sphodros builds webs in grass (though at least one source notes S. rufipes seems to have a preference for smaller trees at their study site). i've posted about my purseweb-in-grass observation in multiple communities, but so far this is the only one to get any responses lol

i don't know what other spiders would build such a web.
i think the first web in the OP was new when i found it, less than a week after an adjacent old field was mowed. i was tempted to flag it so it was easier to keep an eye on, but sure enough i lost it in the long grass (and may have since lost it to a park lawnmower).

the web on the tree in the OP is along a path i walk regularly, and i often wonder if i could tease the spider to attack a tuning fork...

I’ve tried a method similar to a tuning fork using a pair of long forceps, it didn’t work for me. I did however use the forceps to grab an isopod by its end and “walk” it up the web to lure it out

 

[aaarg]

revisiting this topic after spotting two new Sphodros webs yesterday (one along the edge of a field, the other at the base of a tree - both presumably Sphodros rufipes), and i did find some relevant info in the literature.

from Mckenna-Foster et al 2011, " An unusually dense population of Sphodros rufipes (Mygalomorphae: Atypidae) at the edge of its range on Tuckernuck Island, Massachusetts" (emphasis mine):

Vegetation used for web attachment is unusual on Tuckernuck. At the western plot, 83 percent of the webs were attached to non-woody objects (predominantly Pennsylvania sedge, Carex pensylvanica), and 16 percent were attached to a woody shrub. [...] In the eastern plot, 51% of the webs were attached to non-woody objects (again, predominantly C. pensylvanica), and 41% were attached to a woody shrub (predominantly Gaylussacia baccata). One of these webs was attached to a pitch pine (Piunus rigida) (25 cm diameter at breast height). This is unusual, for pines are not mentioned as web supports in any other study. Another 8% were attached to other objects such as a dead leaf, a dead log, or dead pine needles. The webs were on average 9.9 ± 0.88 cm long and the height from the ground to the top, again, varied greatly (0.5-15 cm).

There is only one previous report of S. rufipes using grass as a web support (Muma & Muma 1945), and most studies describe the spiders using trees. Hardy (2003) reported that S. rufipes in his study area used deciduous trees and avoided coniferous trees. Our findings strongly support a view that S. rufipes will use whatever support is available, even the rare conifer. Deciduous trees (mostly oaks) exist on Tuckernuck and form a centrally located forest, but in cursory surveys we did not find any webs attached to these trees. Large oaks were not present in our survey plots. Spiders did use the small woody shrub Gaylussacia baccata. Coyle & Shear (1981) noted that S. rufipes in Florida referred smaller trees (< 10 cm) to larger ones

and from Reichling et al 2011, "Aggregations of Sphodros rufipes (Araneae: Atypidae) in an urban forest":

The majority (65%) of tree genera occurring in Overton Park were utilized by S. rufipes as purseweb supports (Table 1). A large proportion (20%) of spiders utilized small herbaceous plants as web supports, as depicted in Fig. 1. We also observed Sphodros utilizing miscellaneous ground litter as supports, such as fallen dead leaves and limbs (9%). A few webs (6%) were not supported by any structure; i.e., were aligned horizontally upon the forest floor, as is more characteristic of the Old World Atypus (Gertsch & Platnick 1980), or were partially attached to fallen debris.

the pursewebs i spotted yesterday: