Sosippus mexicanus

Excerpts from Jim Conrad's
Naturalist Newsletter

from the June 7, 2018 Newsletter issued from Rancho Regenesis in the woods ±4kms west of Ek Balam Ruins; elevation ~40m (~130 ft), N~20.876°, W~88.170°; central Yucatán, MÉXICO
FUNNEL WEB WOLF SPIDER ON A FENCEPOST
Beside a rancho cowtrail through the woods, an old, decaying fencepost rose up through bushes and weeds. Atop the fencepost a spider's sheet web -- one of those horizontally deployed webs usually seen near the ground -- had been established among a clutter of stems and leaves. It was curious that a sheet web would be shoulder and not ankle high, and the spider was clearly visible waiting for prey to land on the web, so I took a look. The whole thing can be seen below:

A close-up of the spider, with hind legs firmly planted on the shadowy shelter's walls, so that a quick retreat into the hole can be made if threatened, appears below:

Below you have a better look at the head part, nicely showing some of the spider's eight eyes arranged in three rows, and the dark, sharp leg-bristles:

Trying to get even closer than I did for the last picture, the spider spooked and faster than my eyes could follow disappeared into her hole. It was an unusual place for a sheet web hole, but a very effective one, formed where the fencepost's heart had rotted away, shown below:

We've seen sheet-web-weaving spiders similar to this one, in the genus Agelenopsis. You might enjoy comparing the present one with one seen in Mississippi, at www.backyardnature.net/n/a/grass-sp.htm

*UPDATE: Since 2018, many new identification resources have appeared on the Internet, and now this doesn't look like an Agelenopsis. When the above photos were uploaded to the iNaturalist website, in 2025 user "huttonia" recognized the genus Sosippus, whose species commonly are known as Funnel Web Wolf Spiders. When I reviewed Sosippus species encountered in the Yucatan, our spider appears to match SOSIPPUS MEXICANUS, rarely observed in tropical Mexico's lowlands near the coast. Not much is known about the species.

from the June 29, 2019 Newsletter issued from near Tepakán, north-central Yucatán state; elevation ~9m (~30 ft), N21.053°, W89.052°; MÉXICO
FUNNEL WEB WOLF SPIDER IN A STONE WALL
A big spider has taken up residence in a chink in the stone wall of the hut I live in, as you can see in the center of the picture below:

Most of the time the spider hides within the web tunnel's darkness, but whenever I slap a horsefly biting my legs and the fly is only dazed, I pick it up and thump it toward the tunnel, the spider rushes out, and sinks fangs into it, as shown below:

The spider seems to be the same species profiled above, as you can confirm in the picture below, with the lines and spots on the spider's top side plainly visible:

I'm still undertain of this spider's ID, but at least now it's clear that the species may be common in the northern Yucatan. Also, it's worth noting that both times the species has been observed the web was constructed at about the same height, some 1.5m high (5ft), and neither time was the web in grass