Wolf Spider Mystery

by Eric Neubauer

I’ve been watching a large population of Hogna wolf spiders growing up on my property since winter. I’ve submitted photographs to both iNaturalist and BugGuide, and people there don’t hesitate to confirm them all as Hogna antelucana.

Specimen of hogna wolf spider with the vee shape pinched shut.

Nevertheless, I found I can easily sort them into two groups from a fairly young age on. The markings on this species are quite variable in general, but one reliable difference between the two groups is in a lightly colored vee shape near the back of the head. The vee points toward the back and is open at about a 35 degree angle on one type and is pinched shut on the other.

Specimen with an open vee shape.

There are other small differences, but they are harder to define and less consistent.

At first I thought it might be a case of sexual dimmorphism, but lately I think there may be two different species.

The dark one.

The third example has the open vee, hard to see because the spider is looking up, and is very dark with none of the warmer tones these spiders usually have. It is the only one like that I’ve seen and perhaps lacks the ability to produce an orangish pigment.

It is one of several mysteries to keeping life interesting.

Who’s at the Top of the Food Chain Now?

by Eric Neubauer

You’d think a Rabid Wolf Spider would be king of its domain. By the end of last week many had reached their prime and would be thinking about reproduction, but not this one, which was destined to become food for a spider wasp’s offspring instead.

A wasp attacking a spider
Wolf spider played by Rabidosa rabida. Spider wasp played by Tachypompilus ferrugineus. Note that The forelegs of some Rabid Wolf Spiders blacken as they become adults.

I arrived with my camera as the wasp was dragging the paralyzed spider toward its nest. Unfortunately the early morning light was bad and the wasp was fast, so most of the photos were poorly lit and out of focus. Thus, I have to tell most of my story with words.

This is what I saw. The wasp was dragging the spider along. The wasp dropped the spider several times and appeared to wander around before returning. At first I thought it saw me as a threat and was taking evasive action, but as I watched it reach its destination, I realized how entirely focused it had been on the task at hand.

Rabid wolf spider on limestone with fossils.
Bonus photo of a rabid wolf spider, by Sue Ann Kendall.

Wasps don’t have eyes in the back of their heads, so it couldn’t see where it was going while dragging the spider. Every time it dropped the spider, it had gone back to find the opening of its nest to reorient itself as it returned to the spider. It made no sense to drag the spider a long way and then find out it was in the wrong direction.

After dragging the spider about four feet and a couple of final yanks, the wasp and then the spider disappeared under the house skirting.

Making the Best Out of the Materials You Have Available

… the essence of engineering

by Eric Neubauer

I was hardly a fan of spiders, but circumstances have determined otherwise. The pandemic has kept me almost exclusively at home, and the Texas Blacklands appear to be excellent habitat for wolf spiders (Lycosidae).

In the past, getting identifications down to the species level almost always ended up in frustration, except for Rabidosa rabida. I have identified at least three other genera on my property, and there are likely to be more.

Rabid Wolf Spider Rabidosa rabida. Photo by the author.

This year, I decided to make observations of them as they grew up. My goal was to upload at least a hundred observations to iNaturalist before trying to identify them down to species level. I passed my goal by getting 23 in 43 minutes a few days ago.

This Thin-legged Wolf Spider (Genus Pardosa) is a young one. Photo by the author.

Lycosidae are generally considered nocturnal, but this isn’t entirely true. Daytime hunting is hit or miss, but a combination of high humidity after a rain, temperatures in the high 70s, and cloudy skies apparently combined to bring them out in the middle of the day.

This one is not identified yet. Photo by the author.

There is also a matter of technique. I’ve found that closely cut grass next to high grass is the best place to look and photograph them. You can just walk around slowly and watch for movement, but many will escape into the high grass. If you lead with one foot along the edge of the high grass, this flushes more of them into the low grass where they can be photographed.

There is one particular species that is so well camouflaged it’s impossible to see unless it moves. Right now, they are mostly a half to an inch long including the legs, and they are old enough to identify the genus.

Brush-legged Split Wolf Spider Schizocosa ocreata. Photo by the author.

You may also see holes of various sizes in the ground. At present, many are probably Lycosidae burrows. They can be enticed out with a blade of grass, but I’ve found they disappear back down their burrows too quickly to photograph, making it a two person job whenever that becomes an option again.

My habitat is returning prairie on blackland with paths mown through the high grass. Confirmed genera: Hogna, Pardosa, Rabidosa, and Schizocosa. Other non-Lycosidae genera including Dolomedes are encountered.