Pardosa lapidicina group's Journal

It seems worth getting ventral views of the lapidicina species group as the presumed sura has a dark sternum with a much pale outer ring. This refers to the exoskeleton colors as the entire sternum is covered with pale hairs. P. valens appears to have black femora ventrally with a small section of yellow near the distal end and a narrow black ring at the distal end. This is true for both sexes. Males above are black above with most of the carapace bare. The abdomen and edges of the carapace are covered with pale hairs. The female is brown above with a typical pattern faintly visible. Because of the more extensive black on the fermora exoskeleton, the most noticeable leg banding is on the tibia and none on the femur. Also, the top of the trochanter is entirely black. P. mercurialis and vadosa are lighter, and I haven't figured out how to tell them apart consistently. They appear to be easy to differentiate from the other Texas species.

The real test of these P. valens field criteria will be to see if spiders in other parts of their range have the same characteristics. Unfortunately, there just aren't enough observations yet, especially those with ventral views.

I recently got back from a 6 day trip which went as far as Presidio and included 42 fruitful stops along the way. The main objective was to see what kind of lapidicina group spiders were out there. The Rio Grande along both Big Bend parks apparently hosts Pardosa sura. This isn't a well documented species in Texas as it was merged into P. sierra from 1959 to 2010. The original type specimens have been lost, so it's hard to tell if the original P. sura is really the same as the 2010 version. I'm basing my ID on it being where sura should be, not being any other species known to be there, and having some unique traits by which it can be recognized. It was the only lapidicina group species I found in the immediate area. It prefers beaches and bars made of river rocks. I found both males and females as well as juveniles. One female was huge suggesting an advanced age. She had a healthy bunch of spiderlings along for the ride. I doubt I've run across one that old before, and it was interesting to see she had acquired some typically male attributes including loss of leg banding, general darkening, and more pale hairs on her body. Unfortunately there are quite a few stands of giant reed along the river which crowd both the spiders and the fishermen into a shrinking area, so there probably aren't as many spiders on the Rio Grande as in the past. I made stops on the Frio and Pedernales Rivers on the way back and found lots of lapidicina group spiders. There appeared to be multiple species present, as well as some of the lesser Pardosa. It will take a while to work through all the photos. When I'm done, I'll upload the iNat observations.

This was something I was meaning to check out for some time. I'd noticed a peri-adult molt in both Hogna and Pardosa mercurialis. Many of the earlier pattern change are lost during this molt and sexual dimorphism becomes more pronounced. I suspected this wasn't coincident with sexual maturity, and here's the proof:

https://www.inaturalist.org/observations/99620141
https://www.inaturalist.org/observations/90292781

Both are egg sac bearing mercurialis. The first one has the earlier pattern. Although faint in this individual, the pattern around the outside of the thorax consists of a pale band with a dark edge and a couple of dark partitions. The band isn't perfectly even and bulges inward in two places. At least P. lapidicina and vadosa are very similar. In the second one, the band has lost the dark edging and the two dark partitions are replaced with dark darts which point inward. Remember that these patterns are from hairs so sharpness can vary.

So, a good series of photos for species like this would include:

1. juvenile forms, multiple, approximate age determined by size
   (sexual maturity occurs between 1 and 2)

2. adolescent form with juvenile-like pattern and limited sexual dimorphism, near adult size
3. adult form of each sex plus other forms like chocolate and black in mercurialis

It may be reasonable to disregard sex in the juvenile and possibly adolescent forms.

About a dozen sets of images would be needed to thoroughly cover the patterns of mercurialis for field identification of a population.

No wonder field identification of wolf spiders scares most people. Even Barnes, 1959, steers clear of the issue with statements like "Structure and coloration are typical." for mercurialis and "Coloration typical, although most specimens are light brown in color. Sternum pale or dusky. Structure typical." for vadosa, a new species he was introducing.

Previously I had found mercurialis on a stony tributary northwest of the lake. That was my very first encounter with the species. A month or two ago someone observed one along Comanche Trail on the south side of the lake. I wanted to confirm that and did. I also found Arctosa littoralis and a Schizocosa avida juvenile there. I first checked out the rocky area next to the dam on the south side of the outflow and a pebbly beach on the lake next to the south end of the dam. I found mercurialis and only mercurialis in both locations, especially the latter. My next step is to tour western Texas looking for the other lapidicina group species, maybe next spring when the days are warmer and longer. Before leaving I'll check other people's observations and satellite views to figure out my route and stops. Maybe then I'll have enough detailed images to work out the species
IDs. Every little clue will be needed.

Judging from iNaturalist observations, the lapidicina group appears to be absent from coastal Texas and much of the other Gulf States. On a recent trip to Tennessee I decided to test the hypothesis. I used Google Maps satellite view to locate likely habitats along my route of US 79, TX 43, I-20, and I-59. Stops were made in TX, MS, and AL. No stops were made in LA since I couldn't find any likely habitat. All stops came up negative. I thought I found one in Vicksburg sitting on a rock. It was a Pardosa, but not in the lapidicina group. I only visited a few locations in Tennessee near Bristol where I stayed for several days. Otherwise I passed through the state too early or late in the day. The South Holston Dam area looked promising, but the most appropriate habitat was devoid of all life and other areas yielded other species.

I've suspected a hole on the combined lapidicina-mercurialis range, so I took a virtual trip on iNat up the Texas coast, around to the Louisiana coast, and up the east side of the Mississippi River. The latter two sections are not well represented on iNaturalist, and the area west of the Mississippi is likely devoid of the lapidicina group for lack of habitat. Nevertheless, there wasn't a single lapidicina group spider to be found south of Memphis. So, there appear to be shore dwellers from Florida into Alabama, and upland dwellers in widely scattered locations from Texas through to Alabama. Since there are few uplands in Louisiana and Mississippi, and no shore dwellers west of the Mississippi there does appear to be a large area where there are no lapidicina group spiders. Vicksburg has a small amount of likely habitat that would be worth checking out, but unfortunately none of it is accessible.

Last Wednesday was warm and humid, so that was the day to go spider hunting. I wasn't going to let Colorado Bend State Park being closed spoil my trip, and I found my first lapidicina group spiders along the road about a mile outside the park gate. Although there was no water or even a dry wash nearby, it looked like runoff probably crossed the road at that point and more importantly perhaps were the stones scattered over largely treeless grazing land. It turned out there was a pretty active colony there. All appeared to be mercurialis. I checked several more spots along the way home including a small creek near the intersection of TX 580 and CR 1457. On the narrow sand beach along the creek I found a single juvenile Arctosa littoralis. I moved on to a large expanse of exposed bedrock about 30' from the water which was littered with loose stones. It turned out there was a pretty active colony of Pardosa mercurialis there as well. In both places I had to do a lot of stone turning before finding at least one of each sex.

I had hoped to find some vadosa in the area which was downstream from those I found near Menard. The San Saba River had high vertical sides going through town. It's possible that would block any downstream migration of vadosa.

Eric

I used my free time to check out a number of locations around the lakes in the DFW area. I used google maps satellite view to select promising spots in advance. I found lapidicina group spiders in every location I was able to access. I found no compelling reason to think any were not P. mercurialis although there was quite a range in appearance. The most exciting one was a male I found on the riprap beside the boat ramp in Riversbend Park on the way home. The park is on Stillhouse Hollow Lake in Bell County. The spider was jet black with a few patches of white hair. The tibiae and especially the meta tarsi and tarsi were orange. See iNat 99617871. Although dark forms appear among most lapidicina group species, I've never seen one this dark let alone get a a good series of images. I'd highly recommend the shores of that lake. There are multiple accessible locations in parks and alongside boat ramps and only a few people around. There were other Pardosa species, Tigrosa, and Arctosa too. P. mercurialis was in the rockiest places. I had to do a lot of rock flipping to find them since they weren't out and about in the early afternoon. In all I had 28 observations to upload.

Based on 3 females, one with egg sac, believed to be Pardosa vadosa based primarily on range. The species are said to be light in color which may be due to the overall covering of pale creamy hairs on these individuals.

Links to my observations:
https://www.inaturalist.org/observations/96288917
https://www.inaturalist.org/observations/96288916
https://www.inaturalist.org/observations/96288910

A probable juvenile from Utah:
https://www.inaturalist.org/observations/13599267

Found in a similar habitat to P. mercurialis which is common farther east in Texas at least as far as the Brazos River and apparently the only lapidicina group species present. As can be seen below, there are enough differences in general appearance, especially ventrally, to conclude that they are different from mercurialis.

Dorsal:
Carapace:
Length/width = 1.15. (same as mercurialis iNat 92392407)
Posterior eyes form trapezoid, base wider than tall (ratio 1.5 same as mercurialis iNat 92392407).
The area in between is black on the exoskeleton. (mercurialis same)
Posterior medial eyes wider than anterior eyes. (mercurialis same)
Posterior eye are more or less bordered with orange. (same as some mercurialis)
Thorax evenly covered with pale, creamy hairs. (same as some mercurialis but color varies in hue)
Border of thorax as mercurialis and lapidicina.
Hairless back of thorax yellowish, darkened especially at lateral black bands. (tends to be more irregular on mercurialis)
Thoracic furrow only visible on exoskeleton. (usually visible on mercurialis)
Abdomen:
Even row of white hairs guarding connection of thorax and abdomen. (tends to be in tufts on mercurialis)
Medial band ovoid, yellowish in front containing 4 brown spots at edge of cardiac area;
the front of this area has a reddish hue on one individual;
remainder of cardiac area light brown edged in dark brown; wine glass shaped;
yellowish tan patches at sides of bowl; pale yellow-cream below bowl;
series of 4 pairs of yellow circles with dark brown centers begin above base and converge
toward back of abdomen; each pair is underlined by a pale yellow-cream chevron;
the base of the cardiac border is directly in front of the 1st chevron.
(on mercurialis ovoid shape not apparent, 4 pairs of circles present but unclear on mercurialis, not yellow;
outline of cardiac area dotted rather than solid))
Chevrons marked with continous lines rather than triplets of pale patches like mercurialis.
Irregular dark brown marks begin at the lower corners of the bowl extend backwards and outwards
ending in barbs which point back at the centers of the first pair of yellow circles.
(dark areas indistinct and shaped differently on mercurialis)
A pair of dark brown patches connect the ends of the 2nd and 3rd chevron. (also present on mercurialis)
These are prominent on the exoskeleton.
Sides of abdomen paler than top.
Legs:
Boldly annulated with 2 less distinct rings mid femur; distal tips of femur, tibia, and tarsus dark;
proximal half of patella slightly darker; 2 bold rings proximal end and mid tibia;
2 rings proximal end and mid tarsus; general appearance of 8 rings.
Dorsal trochanters consistently yellow with thin orange border;
yellow area containing two bullet shaped black patches.
(mercurialis similar but patches are dart shaped and extend to the orange border)
Tarsi burnt orange with black tips. (mercrialis same)

Ventral:
Carapace:
Sternum black with numerous long, pale cream hairs; coxae similar but generally lighter. (mercurialis similar)
Abdomen:
Covered with short pale and occasionally dark hairs.
Area in front of genital furrow covered with pale cream to yellowish hairs.
Remainder has a rosy hue becoming orange then yellow at back; area below spineret very dark brown;
hues extends up to the middle of the abdomen. (hues absent on mercurialis)
(for mercurialis, entire abdomen has white hairs covering a yellow exoskeleton except that in the genital area
the exoskeleton is darker; the rosy to orange hue is absent, and the area around the spinneret is yellow)
Legs:
Mostly gray to black with yellow in between consitent with dorsal rings.
Underside of femora almost entirely dark gray with lighter hairs except for yellow patch with
black border at distal end; very short hairless area at proximal end also yellow.
An additional yellow patch about 2/3rds of the way down the femur I, II, and III but not femur IV;
some of these yellow patches may be from wear.
Underside of metatarsi and tarsi pale orange.
Underside of pedipalps mostly pale yellowish; distal segment is orange with dark tip.
(for mercurialis, underside of femora, trochanters, and coxae, have consistently white hairs covering a yellow
exoskeleton; and in general the underside is paler)
Chelicera:
Very dark brown. (orangish brown on mercurialis)

Note: the female with the egg sac had a lot more dark orange exoskeleton showing. Apparently much of the hair which was
nearly white had been lost. As a result, much of the exoskeleton pattern is visible including the dark brown thoracic furrow.
This made it easier to compare with preserved specimens. P. mercurialis doesn't appear to be affected by hair loss.

The results:
https://www.inaturalist.org/observations/96288916
https://www.inaturalist.org/observations/96288910
https://www.inaturalist.org/observations/96288917
https://www.inaturalist.org/observations/96288909

The trip was successful in that I found 3 females at Tenmile Crossing and got good photos.
The trip was unsuccessful in that I found no males, and every other prospective location was either inaccessible, not quite the right habitat, or void of Pardosa. The last included Llano. Perhaps downstream from town I might have been more successful.
So, these do appear to be a different species from mercurials and similar to one observed on private property nearby. Although you'd never figure it from the scientific description, I'm pretty sure these are Pardosa vadosa, and I will be able to work out a functional description for live female spiders at least.

Why is the grasshopper link here? Pardosa are always found with pygmy grasshoppers. I suspect Algae, Paratettix, and Pardosa are part of a year round food chain. The only difference between the lapidicina group species and other Pardosa seems to be a strong preference for streams, rivers, and lakes over ponds and ditches.

Eric