— This article by Jerry Cates and Robert Smith, with important inputs from Allen Brady, Paula Cushing, Joey Slowik, and Mandy Howe (Lady Arachnophile), first published on 5 January 2013, was last revised on 13 July 2013. © Bugsinthenews Vol. 14:01(01).
On 3 January 2013 Robert Smith, of Kempner, Texas, wrote:
This spider is about 1-inch long, from tail to head, and 2 inches across with front and rear legs extended. What is it? I have the spider in a terrarium for now in case I want to get more pictures.
Take care, Bob
My first glance at Robert’s photos told me this was going to be an interesting study. It was obviously a wolf spider in the Lycosidae family, based on the easily observable arrangement of the eyes. Richard Bradley, in his recently published book Common Spiders of North America, put it this way:
“Wolf spiders are easy to recognize — they all have an unusual arrangement of their eight eyes… Four of the eyes, the posterior ones, are large, forming a trapezoid at the top of the high carapace. The posterior median eyes are usually the largest and face forward. The posterior lateral eyes are also large and are well behind the PME on the head region, usually facing to the side or even backward… In front of the PME there is a row of four smaller anterior eyes.”
It is also a female, based on the simple pedipalps (the diminutive leg-like structures that stretch outward, in front of the spider’s face) that lack the swollen tarsi that male wolf spiders have. Note also that the abdomen (the spider’s posterior half) is at least as large as the carapace (the prosoma or anterior half of the spider’s body, including the head and thorax), and likely somewhat larger, which is another sign that this is a female. In wolf spider males, the abdomen is noticeably smaller than the carapace.
In several other articles on wolf spiders published on BugsInTheNews, I point out how difficult it has been for me to identify many of these spiders to genus and species. A paltry few, such as the rabid wolf spider, are easily recognized by the unique markings on their dorsal abdomens. Most of the others, however, including the specimen before us here, are not as easy to identify. Part of the problem is my own lack of expertise with the lycosids. As many as 16 genera, comprising more than 238 species of wolf spiders are found in that part of North America that lies north of Mexico, and many of them look a lot alike until their genitalia are examined with a dissecting microscope.
The taxonomical status of the Nearctic species of the wolf spider family (Lycosidae) is presently in a serious state of flux. Things could be worse, though, as much has been revealed about these spiders since Wallace’s revision of the genus Geolycosa in 1942.
In 1962, for example, Allen Brady published a description of the Nearctic genus Sosippus, then followed that up in 1972 with a paper on geographic variation and speciation in the Sosippus floridanus group. In 1979 he published a detailed description of the Nearctic species in the genus Trochosa. In 1983, Charles Dondale and James Redner revised the genus Arctosa for North and Central America, describing or redescribing twelve Nearctic species; later, in 1990, they published a detailed paper on the spiders of Canada and Alaska, many of which — including this one — are also found in a considerable portion of the lower 48 United States. In 1994, Allen Brady and Kelly McKinley published detailed descriptions of five Nearctic species in the genus Rabidosa. In 2004 Beatrice Vogel published a thorough review of 65 Nearctic species in the genus Pardosa, and one Nearctic species in the genus Acantholycosa. In 2007 Allen Brady published a thorough review of the Nearctic spiders in the genus Sosippus, three of whom he had originally described between 1962-1972; that same year Jozef Slowik and Paula Cushing published several papers describing and redescribing several lycosid species, including Camptocosa texana and Hogna coloradensis. In 2009 Slowik and Cushing published a redescription and transfer of the facultative burrowing lycosid Geolycosa grandis to the genus Hogna. Most recently, in 2012, Dr. Brady published a detailed description of the new genus Tigrosa, into which he transferred four species from the genus Hogna, and one from the genus Allocosa.
Notice that, of the eleven papers cited above, six (>50%) were published by Allen Brady, five of them as sole investigator and author. It is sobering to realize how little would be known today about these spiders had Charles Dondale, Allen Brady, Beatrice Vogel, Jozef Slowik, and Paula Cushing — to name but a few of today’s Nearctic lycosid specialists — not toiled so diligently at researching them and publishing their findings. Allen Brady’s work in this field spans more than fifty years, and it is with considerable amazement and gratitude that I respectfully acknowledge the patient manner in which he has listened to, and answered, my questions.
A huge thank you to Robert Smith, the photographer whose images of this spider are displayed in this article. Bob, a retired U.S. Army helicopter pilot with Gulf War combat experience, took great pains to get shots of this spider at practically every angle. Later, he took photos of a field behind his home that is riddled with burrows made by what we presumed to be one or more species of burrowing spider. Later, he diligently collected both males and females of this species, as well as specimens of a trapdoor spider living nearby. Still later, he and his wife located a field in another part of his property which a smaller species of burrowing spider had riddled with burrows, and has begun collecting specimens from that locale for additional studies. This project owes its depth entirely to his attention to detail, the hours he spent scanning the ground for spider burrows throughout his property, his diligent and innovative collection efforts, and his photographic skills. His photos are of such excellent quality that — with the exception of photos taken in my lab in Round Rock — I have published his on-site images exclusively. He took all these photos using a Canon Powershot SX230 HS 12.1 megapixel camera.
In the text provided below the gallery of images that follow I will describe the features that these images portray for this spider.
Please note that all of the photos on this page, as with all the photos on BugsInTheNews.info, may be enlarged for more detailed viewing by simply hovering your cursor over the photo and clicking on it.
This spider, which based on measurements taken from fig. 120 is approximately 22 mm in body length, has a number of distinguishing anatomical features that suggest much concerning its taxonomical identity. My inexperience with the geolycosids, however, led me astray at the start.
For example, the feature that caught my attention at once is the lateral profile of the carapace, depicted well in figures 111 and 121. Specifically, the anterior head appears to be positioned higher than any other portion of the carapace, whereas in most lycosids the highest portion of the carapace is at or near its midmost portion.
The highest portion of this spider’s carapace appears to be between its posterior lateral eyes (PLE), i.e., the eyes furthest back on the head. Such a profile is characteristic of wolf spiders in the genus Geolycosa Montgomery 1904. Charles D. Dondale, in his key to the Lycosidae (Ubick et al., 2005), cites such a profile at the key’s initial couplet, for any lycosid found living in a deep burrow in sandy soil, as sufficient to assign it to the genus Geolycosa. This lycosid female, however, was found wandering about, though under conditions that support the possibility that its burrow may have become inundated by a pouring rainstorm, possibly forcing the spider to abandon her burrow in favor of dry ground. Prudence dictated, however, that I should begin by presuming that this was not a geolycosid and proceed onward in Dondale’s key, to see if its characters correlated with any of the remaining genera.
At couplet 2, I partially eliminated the genus Pirata by virtue of the absence of a V-shaped mark on our specimen’s carapace, and proceeded onward to couplet 3. Here, however, I reached an impasse, as neither of the two choices allowed (A. Tibiae I and II with more than 3 pairs of ventral macrosetae, or B. Tibiae I and II with only 3 pairs of ventral macrosetae) appeared to apply to this specimen. The images in figures 107, 108, and 109 suggested that it had at most one pair of ventral macrosetae on tibiae I and II (though tibiae III and IV are both equipped with three pairs of ventral macrosetae, thus indicating that, if those structures were present on tibiae I and II, I should be able to see them in these photographs).
I supposed it reasonable to persist, then, in my earlier assumption that this was a member of the genus Geolycosa. That led me to Wallace’s revision of that genus which he published in 1942. Though some 20 species of geolycosids are known to be found in North America north of Mexico, only four of them are known — today — to be found in Texas (Dean, 2012). These are listed with their characters below, using — primarily — descriptions provided by Wallace in his 1942 revision of the genus, for females of each species:
- Geolycosa fatifera (Hentz, 1842): sternum, coxae, anterior portion of ventral abdomen (forward of lung slits), pale in color; mid-ventral abdomen (posterior of lung slits) and posterior ventral abdomen to and including spinnerets, jet black; endites and ventral chelicerae darkened; ventral surfaces of leg I and leg II femur, patella, and proximal tibia pale in color, with remainder of tibia and metatarsus darkened;
- Geolycosa latifrons Montgomery, 1904: sternum, coxae, endites, and entire ventral abdomen pale in color; ventral chelicerae darkened to but not including distal extremities and fangs, which are pale in color; all ventral surfaces of leg III and leg IV pale in color; ventral surfaces of leg I and leg II femur, patella, and proximal tibia pale in color, with remainder of tibia and metatarsus of leg I darkened, distal tibia of leg II darkened, but proximal tibia and entire metatarsus of leg II pale;
- Geolycosa missouriensis (Banks, 1895): sternum, coxae, ventral abdomen, pale in color; endites and ventral chelicerae darkened; all ventral surfaces of leg III and leg IV pale in color; ventral surfaces of leg I and leg II femur, patella, and proximal tibia pale in color, with remainder of tibia and metatarsus darkened;
- Geolycosa riograndae Wallace, 1942: sternum and coxae pale (not dark); ventral surface of leg I and leg II patella jet black, while the ventral surfaces of leg III and leg IV patella are pale; proximal ventral portions of leg III and leg IV tibia darkened; entire ventral surfaces of tibia and metatarsus of leg I and leg II darkened; ventral surfaces of entire abdomen, from pedicel to spinnerets, jet black;
Not one of these descriptions matches that of Robert Smith’s specimen, which has a black sternum, darkened coxae (possibly the coxa of leg IV would be more properly described as having a dark surface covered with pale hairs), a ventral abdomen that is light-colored anterior of the lung slits, marked by a prominent jet-black shield with modest lateral wings that extends posteriorly from the lung slits to, but not including, the spinnerets, and laterally in its anterior half beyond the ventrum and up each side to the point that its lateral wings can be seen in photographs of the spider’s lateral habitus (e.g., fig. 112); the ventral patella of all four legs is dark black, a character that Wallace asserts in his revision of the Geolycosa as sufficient to identify a geolycosid as G. riograndae, yet he also points out that the ventral abdomen of G. riograndae is jet black from pedicel to and including the spinnerets, and that the sternum and coxae of that species are pale, quite unlike the specimen before us.
This suggested three possibilities: (1) that this specimen is not a member of the genus Geolycosa, (2) that it represents a previously described geolycosid that has not previously been published as found in Texas, or (3) that it represents a geolycosid species that has not yet been described. Prudence dictated that all of these possibilities be exhausted, and for that reason I also examined the descriptions of all the remaining geolycosid species described by Wallace in his 1942 revision. I may one day post a full set of those descriptions, adapted from the Wallace revision, but suffice it to say at this point that not one of the sixteen species Wallace described matched the specimen depicted here.
We are now 70 years beyond Wallace’s work, and today the genus Geolycosa is recognized to comprise 19 described species that are found in the USA (80 species have been described worldwide). Furthermore, over the years since Wallace published his revision, certain species have been withdrawn and placed in other genera, while others have been moved to this genus from other genera as well.
At that point, I began seeking advice from specialists in the Lycosidae. The first responses to my inquiries strongly questioned the wisdom of placing this spider in the genus Geolycosa. Why? Because those experienced specialists knew, without proceeding further, that it should not be placed in that genus. Their reasoning will become clear in what follows.
I had, unfortunately, asked for advice too early in the project. Too little was known about this spider’s habitat and nothing was known about the burrows it produced in the sandy loam soil of the Kempner, Texas prairie on Bob Smith’s property.
Most geolycosids exhibit a somewhat ho-hum dorsal marking repertoire — whereas this spider’s dorsal markings are robust — and that cast serious doubt on its suitability as a geolycosid candidate, at least for the experts. Despite the difficulties I encountered on trying to key it away from that genus, most of the lycosid specialists who examined photos of this specimen felt that its identity lay elsewhere in the Lycosidae, possibly in the lenta group, whose members display the kind of robust dorsal markings that adorn Bob Smith’s specimen. They are right, of course, but it would take more research on my part before I could arrive at that conclusion.
My reluctance to accept expert advice without checking it thoroughly for validity is, of course, excusable. I speak here as a lifelong skeptic with deep roots in the Missouri Ozarks, where the expression “Show me…” originated. To such as I, healthy skepticism is laudable. It forces one to examine all available alternatives, thereby exacting some degree of proof before accepting a proffered hypothesis. It must also be quite exasperating to those with more experience to encounter skeptics like me, and for having been the source of much exasperation I humbly apologize.
The high anterior carapace on Bob Smith’s female wolf spider was significant, and one reading of Dondale’s key to the Lycosidae interpreted that meaning to be that this had to be a member of the genus Geolycosa. I am still somewhat puzzled at this, but the likely explanation is that keys have limitations; they are made more for those who don’t need them than for those who do. Does that make me — besides a skeptic — also a cynic? Perhaps. But realize this: keys cannot be absolutely exhaustive or they would never get published, so those who prepare them have to assume that the user will bring a lot of specialized knowledge about the subject to the table, knowledge that adds extra, entirely unseen, dimensions to the key’s narrow focus.
The saving grace of the keying process is persistence on the part of the student. Stubborn insistence on arriving at the correct answer, no matter how much research is required to get there, eventually puts the materials in the key in sharp focus. Keys are definitely helpful, but they often take a back seat to grunt labor. Grunt labor, properly expended, leads to the development of specialized knowledge. That, after all, was the real object in the first place.
Once I mentioned to Robert my initial suspicion that this spider was a burrowing wolf spider he informed me that he had been finding large numbers of burrows in a prairie on his property beyond the grassed yard. Generally, as mentioned earlier, geolycosid females are not observed wandering about as was this specimen; the females burrow into the ground a short distance away from their natal burrow and remain there for the remainder of their entire 1-2 year lifespans (Miller & Miller, 1987). It is true that weather conditions in Central Texas during the week prior to this specimen’s discovery included sub-freezing overnight ambient temperatures accompanied by moderate to heavy rainfall, which in combination is known to drive burrowing spiders from their burrows, especially if the burrows become inundated. Those conditions, in fact, were what led me to persist in supposing that this spider was a geolycosid.
But many other spiders burrow into the ground. Tarantulas, for example. And trapdoor spiders. And burrowing wolf spiders, many of which — but by no means all — are in the genus Geolycosa. Some wolf spiders are obligate burrowers, i.e., they build their burrows out of necessity and their females almost never live outside of such structures. Others are facultative burrowers, and may burrow when circumstances either permit or strongly commend such behavior, but those same spiders willingly abstain from burrowing otherwise, without suffering any obvious ill effects.
Wolf spiders in the genus Geolycosa are obligate burrowers. Their females are almost never found outside their burrows, though the males — on reaching sexual maturity — are transformed into inveterate wanderers, spending much if not all of the remainder of their lives searching for females. Many of the wolf spiders in the remaining genera are facultative burrowers, and few if any are true obligate burrowers.
The soils in the vicinity of Kempner are, in general, of sandy loam over decayed limestone, which are well suited for burrowing spiders. This suggests that (1) any facultative burrowing spiders native to the area would find this immediate environment attractive for burrowing, while (2) any obligate burrowing spiders would also do well here.
Bob Smith sent me the following tantalizing message on 6 January:
“Jerry: There is a field on the back 2 acres of my property approx 200 feet by 150 feet that have many of what I believe are spider burrows. The field is not used except for the dogs running around there sometimes and my wife and I going for walks. Otherwise the property is as it was when we bought it and built our house. I always thought they were tarantula burrows because of the ones I have found near our house. Around that field are several more smaller cleared areas that remain the same as when only cattle wandered there. Maybe some of the burrows might be of interest to you. The front one acre also has cleared areas that haven’t been disturbed. I don’t know how you excavate or obtain spiders in the wild but the possibility of finding the spiders here is good.”
I received this news with great interest, and made plans to visit the site on 7 January to locate and photograph the burrows Robert mentioned. On arrival at the site, I took possession of the specimen he had been keeping for me, and later deposited it at my Round Rock laboratory, where it was placed inside a dedicated vivarium provisioned with native soil from the shortgrass prairie at Bob’s home, overlain with remnants of the native ground cover. I noted that although this spider did scoop out a quantity of soil under one of the bunchgrasses — where it rested the way many rabbits rest in shallow depressions they form in the ground — it did not burrow deeply.
The gallery of photographs shown below (all of which, incidentally, were taken by Robert Smith) depict a prairie of hardy, drought-resistant grasses that typically thrive on alkaline soils with poor nutrient profiles. Drought resistant junipers (Cupressaceae: Juniperus spp.) dominate the selection of trees that are native to this area, but a few hardwoods are interspersed as well. In the coming weeks and months I plan to visit this site regularly to map the flora and document the identities of the burrowers that produced the artifacts depicted in these photographs. Note that practically all these burrows are turricolous, i.e., they are provided with crude turrets, in the form of a raised lip composed of native grasses bound together, most likely with silk.
As Carrel points out in his study of two geolycosid species in Florida, the burrows of other arthropods, including spiders from other genera, and even the burrows of many geolycosids, are aturricolous, or bereft of these structures. Some of the burrows in Bob Smith’s shortgrass prairie (e.g., fig. 202) have — instead of a turret — a mound of soil around the burrow mouth, where soil excavated from the burrow had earlier been trucked out of the hole. These possibly mark more recent excavations that will, before long, be decorated with turrets like the burrows nearby, but they may also represent the burrows of other species of spiders. Of those examined closely, the burrows appear to be fairly vertical longitudinally, and nearly symmetrical laterally. Some appear to be plugged (e.g. figs. 214 and 216).
Bob’s Ranch is Home to Multiple Species of Burrowing Spiders:
In the early evening of 7 January, after I had returned to Round Rock, a light rainstorm passed through Kempner. Afterward, in the dark, Bob Smith surveyed the shortgrass prairie depicted in figures 200 and 201, above, using a flashlight. On the way to the prairie, while passing near the swimming pool, he found a male trapdoor spider (a mygalomorph, and likely a member of the Euctenizidae family), which he collected and placed in a plastic container for me to examine later. The prairie fauna, by comparison, appeared quiescent.
In the two days that immediately followed, temperatures throughout Central Texas varied from the mid-30’s to the upper 40’s as, on 8 January, a series of thunderstorms passed through the region, followed by sporadic rain showers on 9 January. On both these days Bob collected four more male trapdoor spiders, one after it entered his home and terrorized his wife who — having previously been warned to be on the lookout for arachnid interlopers — thankfully refrained from smooshing the animal. Two other males were collected from the pool skimmer, after being underwater for an indeterminate amount of time, but possibly for several hours. One of these soon came to life and began pacing incessantly in its plastic bin, in the typical fashion of a male trapdoor spider in search of a female. The other, while initially appearing dead, later revived and exhibited the same behavior as the others.
Early in the morning of 10 January, Bob found a dead male trapdoor spider on the decking around his pool, and soon afterward found a female trapdoor spider in the pool skimmer that, like the two males found the previous day, had been underwater for some time. He placed the female in a collection bin, and it soon revived.
Later that afternoon I dropped by and picked up all these spiders to take them to my lab in Round Rock. While there Bob, his wife, and I surveyed the grassy yard near the pool for trapdoor nests, and found one with its trapdoor halfway open. Bob took photographs of the nest from several angles, in an effort to document the elegance of the burrow’s architecture, and the structure of the trapdoor. A separate article on these spiders is in preparation and will soon be published on BugsInTheNews.
After documenting the trapdoor nest, the three of us looked over two other clearings, then entered a forested area, in the center of which reigned a huge old oak. The circumference of the oak’s trunk was extraordinary, possibly in excess of 15 feet. Gabriella commented on the oak’s obvious age, and we wondered what interesting things this old tree might have witnessed. Bob has found lead musket balls in this area, along with rocks that someone had long ago chipped and sculpted. Who? We may never know. But it was sobering to bask in the evidence of the history of this place.
We then surveyed the shortgrass prairie to see if we could find any of the animals that were inhabiting the burrows we’d photographed on January 7th. It was now dusk, and I had brought a bright LED flashlight with which to peer into the burrows. It soon became obvious that, because we had not yet fully mapped and marked the burrows, our present soiree across the prairie would not bode well for the burrow turrets upon which we might unintentionally tread. Realizing this, we discussed the best means of marking the burrows in the future. An unexpectedly spirited discussion ensued, after which we settled on using golf balls, pressed into the soil. The golf balls would provide each burrow with a permanent marker that projected just enough above the soil to avoid the balls being covered up and lost. The balls would also not project so high as to become a nuisance… or much worse.
Bob and Gabriella, as experienced dog rescuers, care for four mature German Shepherds and two mature Akitas (a large Spitz breed, from the northern mountains of Japan). Five of these six large dogs roam about, and closely inspect, this property throughout the day. Having worked with several dogs in the past that had lost one or both eyes to accidental encounters with sharpened sticks and steel rods, Gabriella has taken great pains to remove all such objects from the property. For that reason, my early suggestion that we use commercial surveyor flags on thin steel rods was not well received. All of us agreed, however, that golf balls will serve with distinction.
Ah, but back to the burrows… We concluded that on my next visit (scheduled for 17 January) I would bring a large bucket of marked golf balls with which to mark the burrows, but that presently we would only examine a few of the burrows with a flashlight to see if their inhabitants could be seen. The first burrow we checked (fig. 300) turned out to be 11.7 mm in diameter. According to the measurements listed for the burrow gallery in figures 203-216, that diameter, plus or minus a millimeter, appears to be a relatively common dimension for the burrows we’ve thus far observed in this particular prairie.
On illuminating this burrow’s interior, I observed the posterior of a spider, several inches down (the mouth of the burrow in figures 301 and 302 is in focus, while the spider — which appears to be near the top — is actually several inches down, rather deep inside the burrow, and is for that reason somewhat out of focus). Looking closer, I noted that the markings of this spider appeared much like those of the specimen depicted in the photos that Bob had sent me on 3 January. While I shined light into the burrow, Bob angled his camera and took several photos. Then I studied the spider a bit longer, to see if more of its body might be brought into view. Momentarily it turned about, so that its head was visible. At this point I could see the orange pubescence of its chelicerae, and their darkened distal margins, as depicted in fig. 118, above. The spider maintained that pose for only a few seconds, then returned to its original head-down posture. It disappeared into the burrow’s depths before Bob could get another photo.
What this means was left for another day. We knew we had much more to do here before the then-foggy picture of things might come into focus. Some of the questions that came to mind were these:
- Was this spider occupying its own burrow, or had it taken over the burrow of another species that it had preyed upon or that had died from other causes, leaving the burrow free for this spider to occupy?
- What species of spider or other animal occupies the other burrows that riddle the surface of this prairie?
- How large is the breeding ground of the dominant species in this location?
Speculation cannot compete with good field work. Fortunately, the prospect for good field studies here was good. Beyond all that, this exercise had already produced an important new friendship, and that alone was priceless. Bob and Gabriella — including Gabriella’s lovely and gracious mother, who lives with them — are extraordinary people, wonderful to work with, passionate about life, and intense lovers of nature. They typify the kind of people everyone should wish themselves fortunate enough to know.
On the evening of 11 January 2013 Bob Smith surveyed several burrows in the shortgrass prairie. He found, in a significant number of them, females of the species of spider addressed in this article. From that evidence alone it now seems reasonable to conclude that these spiders are occupying burrows of their own construction.
Bob did not find spiders of other species, or any other kinds of animals in these burrows. That suggested (incorrectly, as it turns out) that this was the dominant — if not the sole — species in this immediate locale.
Later on that same evening, Bob also managed to find and collect several males of this species. He went out again on the evening of 12 January, hoping to add to this collection, but found no fauna stirring at all. He attributed this result to the fact that temperatures on 11 January were relatively high — in the 60’s — when he was able to collect both males and females, but the temperature had dropped to the low 40’s by the evening of the 12th, when no spiders were to be seen.
Figs. 400-405 are from photos Bob took of the males he collected on 11 January. Note the absence of a sclerotized epigynum in fig. 401, and the enlarged tarsi of the palps, shown in figures 402-403. The male’s carapace is not as dramatically elevated anteriorly as that of the female (fig. 402-403), and in fact gives no indication, by that character, of being a geolycosid. Note, in figs. 401 and 404, that the tibiae and metatarsi of the male’s legs I and II are both covered with fine erect bristles. These bristles are absent in the female (see figs. 107 and 109). The dorsal markings of the carapace and abdomen (fig. 405) are distinctive, as are the markings of the ventrum, including those of the legs (fig. 401). Note that the ventral patella of all four legs is jet black in both the male (fig. 401) and the female (fig. 107, 109).
Both of the males Bob collected on 11 January were found in the open, on the ground, rather than within burrows. These spiders were transferred to the Round Rock lab for microscopic analysis on Sunday, 13 January 2013. One male and one female were weighed to the milligram level on an Ohaus TP200S scale, then prepared for microscopy. Images of the male and female genitalia were taken through the lens of a dissecting microscope. Initial images of those characters were processed on the morning of 14 January 2013 and are published below.
This female, which Bob Smith tagged as female #02 in his collection group, measured 22 mm in body length. Its carapace measured approx. 7 mm in width (complete measurements are in process). The body mass, including the extremities, weighed 1.389 g.
The obscured epigynum of this specimen, as initially observed under magnification, is shown in fig. 500.
After the photo exhibited in fig. 500 was taken, the setae obscuring the anterior half of the sclerotized epigynal structure was removed with forceps. The resulting denuded epigynum is shown in fig. 501.
This structure is generally consistent with what might be termed the “typical” lycosid epigynum, in that it has deep atria, a distinct median septum, and a transverse structure at the posterior extremity of the median septum that, together with the latter, forms an inverted “T”. Though not all lycosid species exhibit epigyna with all of those characters, the vast majority do, and though other families of spiders some of these characters, a survey of the literature suggests that no species outside the Lycosidae family has been found to possess all of them.
A pair of shallow epigynal hoods are positioned at the apical anterior of this specimen’s epigynum. These are separated by a narrow median septum that extends posteriorly to a transverse ledge (described below). Many lycosids have only a single epigynal hood; in others, the depression(s) that in hooded species are partially hidden by a hood are entirely open, without an overlying membrane; others have no depression(s) at the apical anterior of the epigynum.
It differs from typical lycosid epigyna in having the median septum divided into two distinct halves. The anterior half is noticeably narrower than the posterior half, and both halves are separated by the transverse ledge (mentioned above) that divides the epigynum into anterior and posterior portions at its widest extent. This arrangement gives the impression of forming, along this ledge’s posterior edge, on each side of the median septum, a second — essentially mid-most — pair of epigynal hoods. Most likely, the cavities here lead to the female’s seminal receptacles. The internal genitalia of this female has not yet been examined.
The outline of this spider’s epigynum is similar to that of a tri-lobed trèfle, or club, the symbol used on playing cards to denote the card suit by that name (though the apical lobe of the “club” is divided anteriorly by the two shallow hoods). A search of the literature revealed, in Slowik & Cushing, 2007, a strong, but imperfect, similarity with the epigyna described for Hogna coloradensis (Banks 1994).
This male, which Bob Smith had tagged as male #01, measured 16 mm in body length. Its carapace measured approx. 7 mm in width. Its body mass, including extremities, weighed 792 mg.
An anteroventral view of the left palpus is provided in fig. 600, and a retrolateral view of the same palpus is provided in fig. 601.
Detailed descriptions, along with diagrams and detailed measurements of the characters exhibited by the various components of this palpus are in process. A search of the literature revealed, in Slowik & Cushing, 2009, a cursory similarity with some of the characters of the palpus described for Hogna grandis (Banks 1894), specifically in the morphology of the terminal apophysis. The morphology of the median apophysis, on the other hand, bore a greater similarity to that observed in Hogna coloradensis (Banks 1994), as described in Slowik & Cushing, 2007. However, significant differences remain between this specimen and both of the described species cited above.
After contacting Dr. Paula Cushing and Joey Slowik, asking for their help in identifying these spiders, Mr. Slowik suggested it might be Hogna baltimoriana. He based this on the markings displayed on the ventral abdomen, as well as the morphology of the male and female genitalia, as described in 1990 by Dondale and Redner. Unfortunately, I was not privy to that paper at the time, and had no idea how to obtain a copy. Later, on 8 April 2013, Mandy Howe kindly wrote me to collaborate Joey Slowik’s conclusion, and — after a more diligent search of the Internet — I finally found a link to the 1990 paper by Dondale and Redner, observing on page 47 of that document the recorded details of the genitalia noted herein.
Many thanks to all who have assisted with the preparation of this article. This species, though known to be found in far west and northwest Texas, has not previously been observed in central Texas.
- Kingdom Animalia (an-uh-MAYHL-yuh) — first described in 1758 by the Swedish taxonomist Carolus Linnaeus (1707 – 1778), using the Latin word animal = “a living being,” from the Latin word anima = “vital breath”, to refer to multicellular, eukaryotic organisms whose body plans become fixed during development, some of which undergo additional processes of metamorphosis later in their lives; most of which are motile, and thus exhibit spontaneous and independent movements; and all of whom are heterotrophs that feed by ingesting other organisms or their products;
- Phylum Arthropoda (ahr-THROPP-uh-duh) — first described in 1829 by the French zoologist Pierre André Latreille [November 20, 1762 – February 6, 1833], using the two Greek roots αρθρον (AR-thron) = jointed + ποδ (pawd) = foot, in an obvious reference to animals with jointed feet, but in the more narrow context of the invertebrates, which have segmented bodies as well as jointed appendages;
- Subphylum Chelicerata (Kuh-liss-uh-RAH-tah) — first described in 1901 by the German zoologist Richard Heymons [1867 – 1943] using the Greek noun χηλη (KEY-lay) = a claw, talon, or hoof + the Greek noun κερας (Ser-as) = an animal’s horn + the Latin suffix ata — which by convention is suffixed to the names of animal subdivisions — to refer to animals that have specialized appendages before the mouth that they use in feeding, capturing and securing prey and that — in the case of spiders — are further equipped to inject venom and digestive agents into their prey;
- Class Arachnida (uh-RAKH-nuh-duh) — first described in 1812 by the French naturalist and zoologist Jean Léopold Nicolas Frédéric Cuvier [August 23, 1769 – May 13, 1832], usually referred to as Georges Cuvier, using the Greek noun αραχης (uh-RAH-kes) = a spider, in reference to all eight-legged arthropods, including such disparate animals as ticks, mites, scorpions, harvestmen, solpugids, and spiders;
- Order Araneae (uh-RAY-neh-ee) — first described in 1757 by the Swedish entomologist and arachnologist Carl Alexander Clerck [1709 – 22 July 1765], who used the Latin word aranea = a spider or a spider’s web, to refer to eight legged arthropods that spin webs;
- Suborder Opisthothelae (oh-PIS-thoh-THEE-lee) — first described in 1990 by the American arachnologists Richard C. Brusca and Gary J. Brusca, who used the Greek words οπισθεν (oh-PIS-thehn) = behind, at the back, yet to come + θηλη (THEE-lee) = nipple or teat, to distinguish this grouping of spiders from the more primitive spiders in the suborder Mesothelae, in that certain characters (e.g., tergite plates, ganglia in the abdomen, and — in particular, inasmuch as the suborder name is a direct reference thereto — median-positioned spinnerets) of the latter are absent in the former; thus spiders in this suborder have spinnerets positioned at the hindmost portion of the abdomen;
- Infraorder Araneomorphae (Uh-RAY-nee-oh-MOHR-fee) — distinguished from the mygalomorphae by having opposing fangs that open and close perpendicular to the spider body’s longitudinal axis, in a pinching action, whereas spiders in the infraorder mygalomorphae (e.g., tarantulas and trapdoor spiders) have fangs that open and close more nearly in alignment with the spider body’s longitudinal axis.
- Series Entelegynae (inn-TELL-uh-jiy-nee) — araneomorph spiders which, unlike the Haplogynae, have hardened, i.e., sclerotized, female genitalia. Foelix (2011) points out that “entelegyne spiders have more complex reproductive organs (with an epigyne and separate fertilization ducts in the female)…” and that “Male entelegyne genitalia are very diverse…“;
- Superfamily Lycosoidea (lye-koh-SOY-dee-uh) — a superfamily of eight-eyed entelegyne araneomorph spiders comprised of 11 families, 291 genera, and 4,191 species (Platnick 2012a, in the AMNH World Spider Catalog, version 13.5):
- Family Lycosidae (Sundevall, 1833) — 120 genera, 2,393 species (Platnick 2012a; #69 in WSCv13.5; 5 species added since v13.0); commonly known as wolf spiders;
- Family Trechaleidae (Simon, 1890) — 16 genera, 119 species (Platnick 2012a; #70 in WSCv13.5; 1 species added since v13.0); found in Central and South America;
- Family Pisauridae (Simon, 1890) — 48 genera, 331 species (Platnick 2012a; #71 in WSCv13.5; reduced by one genus since v13.0); commonly known as nursery web spiders;
- Family Oxyopidae (Thorell, 1870) — 9 genera, 444 species (Platnick 2012a; #72 in WSCv13.5; 11 species added since v13.0); commonly known as lynx spiders;
- Family Senoculidae (Simon, 1890) — 1 genus, 31 species (Platnick 2012a; #73 in WSCv13.5; unchanged from v13.0); bark-hunter spiders found only in Central and South America;
- Family Stiphidiidae (Dalmas, 1970) — 22 genera, 135 species (Platnick 2012a; #74 in WSCv13.5; unchanged from v13.0); tent-web spiders found in Australia, New Zealand, and Mauritius;
- Family Zorocratidae (Dahl, 1913) — 5 genera, 42 species (Platnick 2012a; #75 in WSCv13.0; unchanged from v13.0); a little known family of hunting spiders;
- Family Psechridae (James, 1989) — 2 genera, 51 species (Platnick 2012a; #76 in WSCv13.5; unchanged from v13.0); lowland funnel-web spiders found only in Southeast Asia;
- Family Zoropsidae (Bertkau, 1882) — 14 genera, 86 species (Platnick 2012a; #77 in WSCv13.5; unchanged from v13.0); commonly known as false wolf spiders, native to Australia and South Africa, with one species (Zoropsis spinimana) introduced into North America, now found in homes in the San Francisco bay area;
- Family Zoridae (F. O. P.-Cambridge, 1893) — 14 genera, 79 species (Platnick 2012a; #78 in WSCv13.5; number of genera and species unchanged from v13.0, but other changes were made to the file); mostly tropical spiders that hunt without webs;
- Family Ctenidae (Keyserling, 1877) — 40 genera, 480 species (Platnick 2012a; #79 in WSCv13.5; 12 species added since v13.0); commonly known as wandering spiders;
- Family Lycosidae (lye-KOH-suh-dee) — first described in 1833 by the Swedish zoologist Carl Jakob Sundevall (1801-1875), who chose the Greek word λύκος (LYE-kos) = wolf, as a reference to the way wolves hunt for and take down their prey, though wolves hunt in packs and the arachnids Sundevall had in mind hunt alone; the spiders in this family are small to large (2.2-35.0 mm) hunting spiders with a distinctive eye arrangement: the anterior eye row (AER) is composed of four small, similarly sized eyes arranged frontally in a line across the front of the carapace just above the clypeus; the posterior eye row (PER) is composed of much larger eyes, such that the posterior median eyes (PME) are arranged frontally, just above the AER, with the posterior lateral eyes (PLE) positioned dorsally, posterior to, generally wider apart than, and forming a quadrangle with, the PME; the egg sac, or cocoon, is carried by the female attached to the spinnerets; when the spiderlings emerge from the egg sac they migrate to the female’s dorsum, where they remain for several days before dispersing; Lycosids come in tan, light brown, to dark charcoal brown background colors, with pale, cream, white, black, yellow or red markings. The carapace and/or abdomen may be boldly or vaguely marked with two or more longitudinal stripes. Legs are long and stout, and are often supplied with dense scopulae; the tarsi have three claws. Vision is used to detect, stalk, and ambush prey in a variety of habitats; this family is comprised, worldwide, of more than 100 genera, of which 16, grouped in four subfamilies and two groups, are known to be represented in North America:
- Subfamily Sosippinae: Genus Sosippus (Simon 1888) — ALE on small tubercles; spiders live on a funnel web;
- Subfamily Venoniinae:
- Genus Pirata (Sundevall 1833) — One species (P. spiniger) has more than 3 pairs of macrosetae on the ventral tibiae of legs I & II; 28 species have a conspicuous v-shaped mark on the anterior carapace; one species (P. bryantae), though having the three pairs of macrosetae on the ventral tibiae of legs I & II, has a totally black carapace, abdomen, and legs I and II;
- Genus Trabeops (Roewer, 1959) —Ventral tibiae I & II with more than 3 pairs of macrosetae;
- Genus Trebacosa (Dondale & Redner, 1981) —
- Subfamily Allocosinae: Genus Allocosa (Banks, 1900) — Generally glabrous carapace;
- Subfamily Pardosinae:
- Genus Acantholycosa (Dahl, 1908) —
- Genus Pardosa (C. L. Koch, 1847) — Ventral tibiae I & II with more than 3 pairs of macrosetae;
- Group Lycosinae-Lycosa:
- Genus Alopecosa (Simon, 1885) —
- Genus Arctosa (C. L. Koch, 1847) — Generally glabrous carapace;
- Genus Lycosa (Latrielle, 1804) —
- Genus Melocosa (Gertsch, 1937) —
- Genus Paratrochosina (Roewer, 1960) —
- Genus Varacosa (Chamberlin & Ivie, 1942) —
- Group Lycosinae-Trochosa:
- Genus Geolycosa (Montgomery, 1904) — Burrowing spiders, lacking dorsal spines on the posterior tibiae in females, but present in males; the cephalothorax viewed laterally is very high in head region, sloping steeply to the pedicel; retromargin of cheliceral fang furrow bears three teeth; females plain grayish to bluish-gray; males with middorsal white stripe on head bordered by black stripe either side, and a black middorsal stripe bordered by white stripe either side on abdomen; females 18-22mm, males 14-16mm;
- Genus Gladicosa Brady, 1987 —
- Genus Hesperocosa (Gertsch & Wallace, 1937) — 1 N.A. species (H. unica); ALE larger than AME;
- Genus Hogna (Simon, 1885) —
- Genus Tigrosa Brady, 2012 — 5 nearctic species, including 4 species transferred from the genus Hogna (Simon, 1885), and 1 species transferred from the genus Allocosa Banks 1900;
- Genus Rabidosa (Roewer, 1960) —
- Genus Schizocosa (Chamberlain, 1904) —
- Genus Trochosa (C. L. Koch, 1847) — AER recurved; paired dark longitudinal streaks in pale area anterior to dorsal groove;
- Ahrens, Lily, and Johanna M. Kraus. 2006. Wolf Spider Movement Along a Pond Edge. J. Arachnology 34:532-539.
- Beccaloni, Jan. 2009. Arachnids. Univ. Calif. Press.
- Brady, Allen R. and Kelly S. McKinley. 1994. Nearctic Species of the Wolf Spider Genus Rabidosa (Araneae: Lycosidae). J. Arachnology 22:138-160.
- Brady, Allen R. 2007. Sosippus Revisited: Review of a Web-building Wolf Spider Genus from the Americas (Araneae, Lycosidae). J. Arachnology 35:54-83.
- Brady, Allen R. 2012. Nearctic species of the new genus Tigrosa (Araneae: Lycosidae). J. Arachnology 40:182-208.
- Carrel, James E. 2003. Ecology of Two Burrowing Wolf Spiders (Araneae: Lycosidae) Syntopic in Florida Scrub: Burrow/Body Size Relationships and Habitat Preferences. J. Kansas Entomological Society 76(1): 16-30.
- Comstock, John Henry. 1912. The spider book: a manual for the study of the spiders and their near relatives. University of Michigan.
- Dean, D. Allen. 2012. Catalog of Texas Spiders. Texas A&M University.
- Dondale, Charles D., and James H. Redner. 1978. Revision of the Nearctic wolf spider genus Schizocosa (Araneida: Lycosidae). The Canadian Entomologist110(2):143-181.
- Dondale, Charles D., and James H. Redner. 1983. Revision of the genus Arctosa C. L. Koch in North and Central America (Araneae:Lycosidae). J. Arachnology 11:1-30.
- Dondale, Charles D., and James H. Redner. 1990. The Insects and Arachnids of Canada, Part 17. Research Branch, Agriculture Canada.
- Dondale, Charles D. 2005. Chap. 37: Lycosidae, in Ubick et al., 2005, Spiders of North America: An Identification Manual. American Arachnological Society.
- Emerton, James H. 1902. The Common Spiders of the United States. Kindle, hardcopy, and paperback editions.
- Foelix, Ranier F. 2011. Biology of Spiders, Third Ed. Oxford Univ. Press.
- Gertsch, Willis J., 1979. American spiders. Von Nostrand Reinhold Company.
- Howell, W. M., and R. L. Jenkins. 2004. Spiders of the Eastern United States: A Photographic Guide. Pearson Edu.
- Jackman, John A. 1999. A Field Guide to Spiders & Scorpions of Texas (Gulf Publishing Field Guide Series). Gulf Press.
- Kaston, B. J. 1978. How to know the spiders (The Pictured key nature series). WCB McGraw Hill.
- Levi, Herbert W., and Lorna Levi. 1987. Spiders and Their Kin (Golden Guide). Golden Press, New York.
- Lubin, Yael, and Trine Bilde. 2007. The Evolution of Sociality in Spiders. Adv. Study of Behav. 37.
- Miller, G. L., and P. R. Miller. 1987. Life cycle and courtship behavior of the burrowing wolf spider Geolycosa turricola (Treat)(Araneae, Lycosidae). J. Arachnology 15:385-394.
- Platnick, Norman I. 2012a. The World Spider Catalog, Version 13.5; FAM. LYCOSIDAE Sundevall, 1833b: 23 [urn:lsid:amnh.org:spiderfam:0100]. American Museum of Natural History.
- Platnick, Norman I. 2012b. The World Spider Catalog, Version 13.5; Currently Valid Spider Genera and Species. American Museum of Natural History.
- Preston-Mafham, Rod. 1996. The Book of Spiders and Scorpions. Barnes & Noble.
- Slowik, Jozef, and Paula E. Cushing. 2007. Redescription of Hogna coloradensis (Banks 1894) from the Southwestern United States (Araneae, Lycosidae). J. Arachnology 35:46-53.
- Slowik, Jozef, and Paula E. Cushing. 2009. Redescription and transfer of Geolycosa grandis (Araneae: Lycosidae) to the genus Hogna. J. Arachnology 37:261-265.
- Suttle, K. Blake. 2003. Short Communication: Burrow Use in a Northern California Population of the Wolf Spider Schizocosa mccooki (Araneae: Lycosidae). J. Arachnology 31:433-436.
- Uetz, George W., Jennifer Bischoff, and Joseph Raver. 1992. Survivorship of Wolf Spiders (Lycosidae) Reared on Different Diets. J. Arachnology 20:207-211.
- Vogel, Beatrice R. 2004. A Review of the Spider Genera PARDOSA and ACANTHOLYCOSA (Araneae, Lycosidae) of the 48 Contiguous United States. J. Arachnology 32:55-108.
- Wallace, H. K. 1942. A revision of the burrowing spider of the genus Geolycosa (Araneae; Lycosidae). Am. Mid. Nat. 27(1):1-61.
- Wickler, Wolfgang.1968. Mimicry in Plants and Animals. World University Library.
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