My first experience with Prionus lure

Our quick stop in Hardtner, Kansas to see “Beetle Bill” Smith at the beginning of our Great Plains Collecting Trip had already produced one unexpected success—the long-sought-after Buprestis confluenta. However, our trip didn’t really begin in earnest until noon the next day when field mate Jeff Huether and I stopped in the middle of a vast, dry grassland north of Las Animas in southeastern Colorado. Even at this point we hadn’t gotten to the first of our planned localities a little further south where we were hoping to find longhorned beetles in the genus Prionus, the main objective of the trip, using recently developed pheromone lures. Jeff had, however, collected an interesting blister beetle at this spot on an earlier trip and wanted to take another look since we were in the area. I looked out across the desolate landscape and wondered what on Earth I could find here that would be even remotely interesting to me.

Shortgrass prairie, 10.5 mi N of Las Animas, Colorado.

Shortgrass prairie, 10.5 mi N of Las Animas, Colorado.

I was convinced there was no point for me to look around, but I wanted to let Jeff have some time to look for his blister beetle, so I milled around the vicinity of the car to look for any flowers that might be in bloom and hoped to maybe see a tiger beetle or two. As is often the case, plants were a little lusher and more diverse along the roadsides due to rain shedding by the road, so I decided to walk down the roadside and see what I might find. I hadn’t gone too far when I saw a big, brown beetle crawling along the edge of the road. My first thought while approaching it was ground beetle, but I quickly decided it was not that. Only when I crouched down and looked at the beetle, crawling with some urgency but making no attempt to fly, did I realize that it was a female Prionus (later identified as P. integer LeConte, 1851 in the subgenus Homaesthesis). I had, in fact, only once before ever seen a female Prionus, that being the ginormous species P. heroicus in southeastern Arizona almost 30 years ago. Incredible! We hadn’t even gotten to the first spot where we planned to look for Prionus, and I’d already found one. And a female, no less!

Prionus integer female

Prionus (Homaesthesis) integer LeConte, 1851 (female).

Jeff was out of ear-shot, so I resumed my walk along the roadside to look for more. Not long afterwards I found a male carcass laying on the ground, and then shortly afterwards I found another one. One of the carcasses was in pretty good condition still, giving me optimism that I would find a live one as well. Frustratingly, however, I saw nothing more during the next hour as I continued slowly down the road to a distance of nearly one mile from the car and then along the other side all the way back. During the time that I was searching, I noticed strange burrows in the ground. They were only along the roadsides and were especially numerous in the area where I had found the female and two male carcasses. The diggings looked fresh, so I tried excavating a few. They were no more than two inches deep, and I found nothing in any of the dozen or so burrows that I excavated. Nevertheless, I was convinced that the burrows were somehow associated with the Prionus beetles that I had found (even though I had never heard of burrows associated with adult Prionus beetles, nor have I been able to find anything in the literature since)—the size of the burrow matched that of the beetles perfectly, and the presence of fresh diggings meant something had made them recently. If the Prionus beetles didn’t make them, then what did?

Prionus integer burrow

Prionus integer adult burrow.

All the time as I was searching, I wondered if Jeff knew about the beetles occurring here. However, when we finally met up again near the car and I showed him what I had found, I could see by the surprised look on his face that this was not the case. I also showed him the burrows that I’d found, and we both agreed they had to be connected to the beetles. I decided to try using a shovel instead of my knife to excavate more burrows, thinking that maybe I wasn’t excavating deep enough, so we got the shovel out of the truck, walked to the area where I had seen the live female, sunk the shovel deep into the ground next to one of the burrows, and pried up a chuck of the soil containing the burrow in its entirety. As we broke apart the soil there it was—another female!

Prionus integer female

A female Prionus integer dug from her burrow (shovel in lower right).

We excavated more burrows in the vicinity, preferentially choosing those with the freshest-looking diggings, and while most were empty we did find several more females. We were beginning to think that only the females created the burrows, but eventually a male was dug from its burrow as well. By now it was clear that we needed to make the first schedule change of the trip (before even reaching the first planned locality!) and decided to set out lure-baited traps and check them later in the evening before resuming our plans the next day. We expected the beetles to become active during dusk, so we went into town to eat dinner and check out a nearby locality before returning to the site. While we were gone heavy rains moved through  the area, and we weren’t sure if or how this would affect beetle activity and their possible attraction to the traps. However, as we approached the site (slipping and sliding on the muddy 2-track), we could actually see beetles crawling on the road from afar. What we found when we got out of the car was nothing short of mind-blowing—beetles were everywhere, crawling on the road, crawling through the grass, and overflowing in the flooded traps! The vast majority, as expected, were males—distinguishable by their smaller size and distinctly flabellate antennae—but we also found a fair number of the much more rarely collected females—most of them either mating or digging burrows.

Prionus integer mating pair

A male Prionus integer attempts to mate with a female.

It was tempting to focus on just collecting individuals, as we had clearly encountered an ephemeral emergence event. However, it was soon apparent that the number of individuals milling around and flying into the area was far greater than what we could possibly put in our bottles. As I gradually realized this, my focus shifted from collecting to observing—especially the females involved in mating and digging burrows. Most of the females that I saw digging burrows had their abdomens protruding from the burrow as they used their front legs to dig soil from the burrow, but eventually I noticed a burrow that had a female sitting completely within the burrow with her head just below and facing towards the burrow opening.

Prionus integer female

A Prionus integer female sits in her burrow.

I crouched down and watched the female closely (through the camera lens) and noticed a regular, almost rhythmic movement by the beetle as she sat in the burrow. I imagined perhaps the female was in the act of oviposition, although I now think it unlikely that this is the case (it doesn’t make sense for a female to make the energetic expenditure to dig a burrow large enough to contain the adult body when a simple probe of the ovipositor into the soil surface would accomplish the same thing. It also occurred to me that the female was emitting pheromone to attract males, but this begs the same question: why call for mates while enclosed within a burrow when doing so from the surface would be just as (and possibly more) effective. At any rate, the chance to observe mating and other behaviors made the encounter far more informative than if our focused had remained strictly on collecting the abundance that we had encountered.

Prionus integer female

Prionus integer female moving rhythmically in her burrow, but why?

Barr & Penrose (1969) give the only biological notes I am aware of for this species, noting that the larvae have been associated with the roots of sagebrush (Artemisia tridentata) and yellow rabbitbrush (Chrysothamnus viscidiflorus) and on two occasions finding larvae damaging newly planted beans or cutting underground stems of potato plants in southern Idaho. In both cases the fields had been recently cleared for cultivation, suggesting opportunistic feeding by larvae that were already present in the soil and feeding on native hosts when the land was cleared. At any rate, the site where we found the species was completely devoid of any rangeland shrubs, suggesting that herbaceous plants also may serve as suitable hosts for the species. We did observe small bunch grasses that were abundant in the area where both the beetles and their burrows were most numerous—in fact (although perhaps coincidentally), the burrows seemed most often to have been dug at the base of these grasses (see 3rd and 6th photos).

The sinking sun in the west and receding storm clouds in the east created conditions ripe for rainbows—a fitting exclamation point to our first (and completely unexpected) Prionus success of the trip. As the cloak of dusk descended, we packed up our gear and headed into town full of optimism about what other Prionus experiences lay ahead in the coming days.

Rainbow over shortgrass prairie

A rainbow hangs over the shortgrass prairie.

REFERENCE:

Barr, W. F. & R. L. Penrose. 1969. Notes on the distribution and bionomics of some Idaho Cerambycidae (Coleoptera). Great Basin Naturalist 29:88–95 [Biodiversity Heritage Library].

© Ted C. MacRae 2014

Amorpha borer on goldenrod

Megacyllene decora (amorpha borer) | Stoddard Co., Missouri

Megacyllene decora (amorpha borer) | Stoddard Co., Missouri

One of my favorite longhorned beetle species is the amorpha borer, Megacyllene decora. Like its close relative, the locust borer—M. robiniae, this large, beautiful, black and yellow beetle is a classic harbinger of fall by virtue of its late-season adult activity period and affinity to flowers of goldenrod (Solidago) and snakeroot (Eupatorium). Compared to the locust borer, however, it is larger, chunkier, and more boldly marked, and despite the commonness of goldenrod flowers it is far less commonly encountered than the locust borer due to the more restricted habitat preferences of the larval host plant (false indigo—Amorpha fruticosa).

Megacyllene decora
The beetle in these photos is one of two that I found in late September at a site in the lowlands of southeastern Missouri. I’ve not seen the beetle at this site before, but I knew it must occur here because of the stands of false indigo that I noted during an earlier visit to the site. Considering the large number of plants present, two beetles is much less than I would have expected to see (in fact, both beetles were found in a single patch of goldenrod). I have previously featured this species (see A classic fall ‘bycid) from a site about 50 miles east of this one. At that site also only a few beetles were seen despite an abundance of larval host plants (but the adults occurring on snakeroot flowers instead of goldenrod). Only twice have I seen this species in numbers that I would consider plentiful (both times in western Missouri).

Megacyllene decora
Amorpha borers and locust borers are part of a larger complex of black and yellow insects that visit goldenrod flowers in the fall. These include a variety of bees, wasps, and other beetles (e.g., the delta flower scarab, Trigonopeltastes delta—family Scarabaeidae), but perhaps the most abundant is the goldenrod soldier beetle, Chauliognathus pensylvanicus—family Cantharidae (also called the Pennsylvania leatherwing). One can presume that any or all of these species serve as models for the longhorned beetles—bees and wasps are obviously protected from most predators by their ability to sting, and the bodies of soldier beetles are chemically protected by cantharidin, a highly toxic terpenoid that causes blistering and irritation of mucous membranes at low doses and can be fatal at higher doses. As the mimics, amorpha borers and locust borers could be expected to be less abundant than the models. However, considering how difficult-to-see these beetles can be when sitting on goldenrod flowers, their black-and-yellow coloration seems as though it could just as easily serve a cryptic function. It is even possible that mimicry and crypsis both have contributed to evolution of these beetle’s coloration.

Ted C. MacRae 2014

2014 Great Plains Collecting Trip iReport

During the past year or so I’ve followed up my longer (one week or more) insect collecting trips with a synoptic “iReport”—so named because they are illustrated exclusively with iPhone photographs. It may come as a surprise to some, but iPhones actually take pretty good pictures (especially if you pay attention to their strengths and weaknesses), and their small, compact size makes it easy to take lots of photos while trying to use time in the field wisely. I find the iPhone to be a great tool for documenting the general flavor of a trip and for taking quick photos of subjects before getting out the big rig. I will, of course, feature photographs taken with the ‘real’ camera in future posts.

For this trip, I teamed up with Jeff Huether for the third time since 2012. Our quarry for this trip was longhorned beetles (family Cerambycidae) in the genus Prionus. Larvae of these beetles are subterranean, with some species feeding on roots of woody plants and others on roots of grasses and other herbaceous plants. Among the latter are an array of species occurring in the Great Plains, many of which have been very uncommonly collected. However, in recent years lures have been produced that are impregnated with prionic acid—the principal component of sex pheromones emitted by females in the genus. Originally produced for use in commercial orchards (which are sometimes attacked by P. laticollis in the east and P. californicus in the west), these lures are proving themselves to be useful for us taxonomist-types who wish to augment the limited amount of available material of other, non-economic species in the genus. While Prionus was our main goal, rest assured that I did not pass on the opportunity to find and photograph other beetles of interest.

I began the trip by driving from St. Louis to Wichita, Kansas to meet up with Jeff, who had flown there from his home in upstate New York. Our plan was to visit sites in southeastern Colorado and northeastern New Mexico, where several of the Prionus spp. that we were looking for were known to occur. Before doing this, however, we stopped in Hardtner, Kansas to see “Beetle Bill” Smith and tour his amazing natural history tribute, Bill and Janet’s Nature Museum.

"Beetle" Bill Smith, founder of Bill & Janet's Nature Museum, Hardtner, Kansas.

“Beetle Bill” Smith, founder of Bill & Janet’s Nature Museum, Hardtner, Kansas.

After the tour (and a delicious lunch at his house of fried crappie prepared by his wife Janet), we headed west of town and then south just across the state line into Oklahoma to a spot where Bill had found a blister beetle (family Meloidae) that Jeff was interested in finding. During lunch I mentioned a jewel beetle (family Buprestidae) that I had looked for in the area several times, but which had so far eluded me—Buprestis confluenta. Emerald green with a dense splattering of bright yellow flecks on the elytra, it is one of North America’s most striking jewel beetles and is known to breed in the trunks of dead cottonwoods (Populus deltoides). Bill mentioned that he had collected this species at the very spot where we were going, and when we arrived I was enticed by the sight of a cottonwood grove containing several large, dead standing trunks—perfect for B. confluenta.

Buprestis spp. love large, dead, barkless cottonwood trunks.

Buprestis spp. love large, dead, barkless cottonwood trunks.

I searched for more than one hour without seeing the species, though I did find a few individuals of the related (and equally striking) B. rufipes on the trunks of the large, dead trees. Once that amount of time passes I’m no longer really expecting to see what I’m looking for, but suddenly there it was in all of its unmistakable glory! It would be the only individual seen despite another hour of searching, but it still felt good for the first beetle of the trip to be one I’d been looking for more than 30 years!

Buprestis (Knulliobuprestis) confluenta, on large, dead Populus deltoides trunk | Woods Col., Oklahoma| USA: Oklahoma

Buprestis confluenta, on the trunk of a large, dead cottonwood (Populus deltoides) | Woods Col., Oklahoma| USA: Oklahoma

I usually wait until near the end of a collecting trip to take the requisite selfie, but on this trip I was sporting new headgear and anxious to document its maiden voyage. My previous headgear of choice, a vintage Mambosok (impossible to get now), finally disintegrated after 20 years of field use, and on the way out-of-town I picked up a genuine Buff® do-rag. I know many collectors prefer a brim, but I don’t like they way brims limit my field of vision or get in the way when I’m using a camera. Besides, I’m usually looking down on the ground or on vegetation, so sun on my face is not a big issue. And do I be stylin’ or wut?

A "selfie" makes the trip official.

A “selfie” makes the trip official.

We made it to our first locality in southeast Colorado by noon the next day—the vast, dry grasslands north of Las Animas. Jeff had collected a blister beetle of interest here on an earlier trip, but as I looked out across the desolate landscape I wondered what on Earth I could find here that would be even remotely interesting to me.

Shortgrass prairie habitat for Prionus integer.

Shortgrass prairie habitat for Prionus integer.

Letting Jeff have some time to look for his blister beetle, I started down the roadside and after a short time found a live female Prionus sp. (later determined to represent P. integer). The only female Prionus I had ever collected before was P. heroicus, a giant species out in Arizona, and that was almost 30 years ago, so I wasn’t immediately sure what it was. Eventually I decided it must be Prionus, and a quick stop to kick the dirt while Jeff looked for his beetle turned into an intense search for more Prionus that surely were there. I did find two male carcasses shortly thereafter, and then nothing more was seen for the next hour or so.

Prionus integer male | Bent Co., Colorado

Prionus integer male (found dead) | Bent Co., Colorado

During the time that I was searching, however, I started noticing strange burrows in the ground. I excavated a few—they were shallow but contained nothing. Nevertheless, they matched the size of the beetles perfectly—surely there was a connection?

Prionus integer adult burrow.

Prionus integer adult burrow.

I wondered if Jeff knew about the beetles occurring here, but when I showed him what I had found the surprised look on his face told me this was not the case. I showed him the burrows, and we both agreed they had to be connected. I got the shovel out of the truck and walked back to the area where I had seen the live female, then sunk the shovel deep into the ground next to one of the burrows and pried up a chuck of the soil containing the burrow in its entirety. As we broke apart the soil another female was revealed, and we immediately decided to set out some traps baited with prionic acid lures. We expected the beetles to become active during dusk, so we went into town to get something to eat and then check out another nearby locality before returning to the site at dusk. While we were gone it rained heavily at the site, so we weren’t sure if or how this would affect beetle activity and their possible attraction to the traps. However, as we approached the site (slipping and sliding on the muddy 2-track), we could actually see beetles crawling on the road from afar. What we found when we got out of the car was nothing short of mind-blowing—the beetles were everywhere, crawling on the road, crawling through the grass, and overflowing in the flooded traps! The vast majority were males, as expected, but we also found a fair number of the much more rarely collected females. This was significant, as the chance to observe mating and oviposition behavior made the encounter far more informative than if we had only found and collected the much more numerous males.

Prionus integer mating pair.

Prionus integer mating pair.

The following day we headed south into northeastern New Mexico to look at some shortgrass prairie sites near Gladstone (Union Co.) where two species of Prionus had been collected in recent years: P. fissicornis (the lone member of the subgenus Antennalia) and P. emarginatus (one of eight species in the poorly known subgenus Homaesthesis, found primarily in the Great Plains and Rocky Mountains). Fresh off of our experience the previous day, we were on the lookout for any suspicious looking “burrows” as we checked the roadsides at several spots in the area but found nothing, and while a few blister beetles piqued the interest of Jeff at one site, the complete absence of woody vegetation or flowering plants in general in the stark grassland landscape made the chances of me finding any other woodboring beetles remote. Eventually I became distracted by the lizards that darted through the vegetation around us, including this lesser earless lizard (Holbrookia maculata) and a collared lizard (better photos of both forthcoming).

Holbrookia maculata (lesser earless lizard) | Union Co., New Mexico.

Holbrookia maculata (lesser earless lizard) | Union Co., New Mexico.

Despite no clues to suggest that Prionus beetles were active in the area, we set out some traps at two sites with soil exposures that seemed similar to those seen the day before. As Jeff set the last pair of traps in place, my distraction with saurian subjects continued with a dusty hognose snake (Heterodon nasicus gloydi). While photographing the animal I looked down to my side, and what did I see but a male Prionus fissicornis crawling through the vegetation! I called out to Jeff, and for the next half an hour or so we scoured the surrounding area in a failed attempt to find more. We would not be back until the next morning to check the traps, so our curiosity about how abundant the beetles might be would have to wait another 18 hours. We cast an eye towards the north and watched late afternoon thunderstorms roll across the expansive landscape and decided to check out the habitat in nearby Mills Rim.

Thunderstorms over shortgrass prairie.

Thunderstorms over shortgrass prairie.

The rocky terrain with oak/pine/juniper woodlands at Mills Rim was a dramatic contrast to the gently rolling grasslands of the surrounding areas. We came here mostly out of curiosity, without any specific goal, but almost immediately after getting out of the car a huge Prionus male flew up to us—almost surely attracted by the scent of the lures we were carrying. Within a few minutes another male flew in, and then another. Because of their huge size and occurrence within oak woodland habitat, we concluded they must represent P. heroicus, more commonly encountered in the “Sky Islands” of southeastern Arizona. We stuck around to collect a few more, but as dusk approached we returned to the surrounding grasslands to set out some lures to see if we could attract other Prionus species. The frontal system that had waved across the landscape during the afternoon had left in its wake textured layers of clouds, producing spectacular colors as the sun sank inexorably below the horizon.

Sunset over shortgrass prairie.

Sunset over shortgrass prairie.

This attempt to collect grassland Prionus beetles would not be successful, and as dusk progressed we became distracted collecting cactus beetles (Moneilema sp., family Cerambycidae) from prickly pear cactus plants (Opuntia sp.) before darkness ended our day’s efforts. This did not mean, however, that all of our efforts were done—there are still night active insects, and in the Great Plains what better nocturnal insect to look for than North America’s largest tiger beetle, the Great Plains giant tiger beetle (Amblycheila cylindriformis, family Cicindelidae—or subfamily Cicindelinae—or supertribe Cicindelitae, depending on who you talk to)?! We kept our eyes on the headlamp illuminated 2-track as we drove back to the highway and then turned down another road that led into promising looking habitat. Within a half-mile of the highway we saw one, so I got out to pick it up and then started walking. I walked another half-mile or so on the road but didn’t see anything except a few Eleodes darkling beetles (family Tenebrionidae), then turned around and walked the habitat alongside the road on the way back. As I walked, tiny little rodents—looking like a cross between a mouse and a vole—flashed in and out of my headlight beam as they hopped and scurried through the vegetation in front of me. Most fled frantically in response to my attempted approach, but one, for some reason, froze long enough under my lamp to allow me this one photo. When I posted the photo on my Facebook page, opinions on its identity ranged from kangaroo rat (Dipodomys sp.) silky pocket mouse (Perognathus flavus) to jumping mouse (Zapus sp.). Beats me.

silky pocket mouse? Zapus sp., jumping mouse? | Union Co., New Mexico.

Kangaroo rat? Silky pocket mouse? Jumping mouse? | Union Co., New Mexico.

Almost as if by command, it rained during the early evening hours where we had set the traps, and the following morning we were rewarded with traps brimming with Prionus fissicornis males. Not only were the traps full, but males were still running around in the vicinity, and we even found a few females, one of which was in the act of ovipositing into the soil at the base of a plant.

Prionic acid-bated traps w/ Prionus fissicornis males.

Prionic acid-bated traps w/ Prionus fissicornis males.

Prionic acid-bated traps w/ Prionus fissicornis males.

Prionic acid-bated traps w/ Prionus fissicornis males.

Prionus fissicornis male | Harding Co., New Mexico.

Prionus fissicornis male | Harding Co., New Mexico.

Prionus fissicornis oviposition hole.

Prionus fissicornis oviposition hole.

Eventually P. fissicornis activity subsided, and we decided to go back to the area around Mills Rim to see what beetles we might find in the woodland habitats. We also still were not sure about the Prionus beetles we had collected there the previous day and whether they truly represented P. heroicus. The scrubby oaks and conifers screamed “Beat me!”, and doing so proved extraordinarily productive, with at least a half-dozen species of jewel beetles collected—including a nice series of a rather large Chrysobothris sp. from the oaks that I do not recognize and a single specimen of the uncommonly collected Phaenops piniedulis off of the pines.

Oak/juniper woodland at Mills Canyon, habitat for Prionus heroicus.

Oak/juniper woodland at Mills Canyon, habitat for Prionus heroicus.

Not only is the scenery at Mills Rim Campground beyond spectacular, it also boasts some of the most adoringly cute reptiles known to man—such as this delightfully spiky horned lizard (I prefer the more colloquial name “horny toad”!). I’m probably going to regret not having photographed this fine specimen with the big camera.

Phrynosoma cornutum (Texas horned lizard) | Harding Co., New Mexico.

Phrynosoma cornutum (Texas horned lizard) | Harding Co., New Mexico.

Fresh diggings beside a rock always invite a peek inside. You never know who might be peeking out.

Who's home?

Who’s home?

Peek-a-boo!

Peek-a-boo!

The trip having reached the halfway point, we debated whether to continue further south to the sand dunes of southern New Mexico (with its consequential solid two-day drive back to Wichita) or turn back north and have the ability to collect our way back. We chose the latter, primarily because we had not yet had a chance to explore the area around Vogel Canyon south of Las Animas, Colorado. We had actually planned to visit this area on the day we encountered P. integer in the shortgrass prairie north of town, and a quick visit before going back to check the traps that evening showed that the area had apparently experienced good rains as shown by the cholla cactus (Cylindropuntia imbricata) in full bloom.

Cylindropuntia imbricata | Otero Co., Colorado.

Cylindropuntia imbricata | Otero Co., Colorado.

Whenever I see cholla plants I can’t help myself—I have to look for cactus beetles (Moneilema spp.). It had rained even more since our previous visit a few days ago, and accordingly insects were much more abundant. Several Moneilema adults were seen on the cholla, one of which I spent a good bit of time photographing. The iPhone photo below is just a preview of the photos I got with the big camera (which also included some very impressive-sized cicadas—both singing males and ovipositing females). The cactus spines impaled in the camera’s flash control unit serve as a fitting testament to the hazards of photographing cactus insects!

Moneilema sp. on Cylindropuntia imbracata } Otero Co., Colorado.

Moneilema sp. on Cylindropuntia imbracata } Otero Co., Colorado.

The hazards of photographing cactus beetles.

The hazards of photographing cactus beetles.

Later in the afternoon we hiked down into the canyon itself, and while insects were active we didn’t find much out of the ordinary. We did observe some petroglyphs on the sandstone walls of the canyon dating from the 1200s to the 1700s—all, sadly, defaced by vandals. Despite the rather uninspiring collecting, we stayed in the area for two reasons: 1) Jeff wanted to setup blacklights at the canyon head in hopes of collecting a blister beetle that had been caught there on an earlier trip, and 2) I had noted numerous Amblycheila larval burrows in the area (and even fished out a very large larva from one of them) and wanted to search the area at night to see if I could find adults. Jeff was not successful in his goal, and for a time I thought I would also not succeed in mine until we closed up shop and started driving the road out of the canyon. By then it was after 11 p.m. and we managed to find about a half-dozen A. cylindriformis adults. This was now the third time that I’ve found adults of this species, and interestingly all three times I’ve not seen any beetles despite intense searching until after 11 p.m and up until around midnight.

Lithographs on canyon wall | Mills Canyon, Colorado.

Lithographs on canyon wall | Mills Canyon, Colorado.

The next morning we found ourselves with two days left in the trip but several hundred miles west of Wichita, where I needed to drop Jeff off for his flight back home before I continued on home to St. Louis. I had hoped we could make it to the Glass Mountains just east of the Oklahoma panhandle to see what Prionus species might be living in the shortgrass prairies there (and also to show Jeff this remarkable place where I’ve found several new state records over the past few years). As we headed in that direction, I realized our path would take us near Black Mesa at the western tip of the Oklahoma pandhandle, and having been skunked on my first visit to the area last year due to dry conditions but nevertheless intrigued by its very un-Oklahoma terrain and habitat I suggested we stop by the area and have a look around before continuing on to the Glass Mountains. We arrived in the area mid-afternoon and headed straight for a rock outcropping colonized by scrub oak (Quercus sp.) and pinyon pine (Pinus sp.)—very unusual for western Oklahoma—that I had found during my previous trip.

The author looks pensively out over the Black Mesa landscape.

The area around Black Mesa couldn’t be more unlike the perception that most people have of Oklahoma.

I wanted to beat the oaks for buprestids—surely there would be a state record or two just sitting there waiting for me to find them, but as I started walking from the car towards the oaks the approach of a loud buzz caught my attention. I turned around to see—would you believe—a large Prionus beetle circling the air around me and was fortunate to net it despite its fast and agile flight. I hurried back to the car to show Jeff what I had found; we looked at each other and said, “Let’s collect here for a while.” The beetle had apparently been attracted to the lures in the car, so we got them out, set them up with some traps, and went about beating the oaks and watching for beetles to fly to the lure. Sadly, no  jewel beetles were collected on the oaks, although I did find evidence of their larval workings in some dead branches (which were promptly collected for rearing). Every once in a while, however, a Prionus beetle would fly in, apparently attracted to the lure but, curiously, never flying directly to it and falling into the trap. Many times they would land nearby and crawl through the vegetation as if searching but never actually find the trap. However, just as often they would approach the trap in flight and not land, but rather continue circling around in the air for a short time and before suddenly turning and flying away (forcing me to watch forlornly as they disappeared in the distance). Based on their very large size, blackish coloration and broad pronotum, we surmised (and later confirmed) these must also be P. heroicus, despite thinking (and later confirming) that the species was not known as far east as Oklahoma. Not only had we found a new state record, but we had also recorded a significant eastern range extension for the species. And to think that we only came to Black Mesa because I wanted to beat the oaks!

Prionus heroicus male

Prionus heroicus male

Bite from Prionus heroicus male.

Proof that Prionus heroicus males can bite hard enough to draw blood!

We each collected a nice series of the beetles, and despite never witnessing the beetles actually going to the traps a few more were found in the traps the next morning after spending the night in a local bed & breakfast. I also found a dove’s nest with two eggs hidden in the vegetation, and as we were arranging for our room at the bed & breakfast a fellow drove up and dropped off a freshly quarried dinosaur footprint (the sandstone, mudstone, and shale deposits around Black Mesa are the same dinosaur fossil bearing deposits made more famous at places like Utah’s Dinosaur National Monument).

Dove's nest w/ eggs.

Dove’s nest w/ eggs.

Dinosaur fossil footprint

Freshly quarried dinosaur fossil footprint

By the way, if you ever visit the area, the Hitching Post at Black Mesa is a great place to stay. A longhorn skull on the barn above an authentic 1882 stagecoach give a hint at the ambiance, and breakfast was almost as good as what my wife Lynne can do (almost! 🙂 ).

Longhorn skull on barn at our Bead and Breakfast.

Longhorn skull on barn at our Bead and Breakfast.

132-year-old stagecoach - model!

132-year-old stagecoach – model!

After breakfast we contemplated the long drive that lay between us and our arrival in Wichita that evening—our longer than expected stay in the area had virtually eliminated the possibility to collect in the Glass Mountains. Nevertheless, there was one more thing that I wanted to see before we left—the dinosaur footprints laying in a trackway along Carrizo Creek north of the mesa. I only knew they were in the area based on a note on a map, but as there were no signs our attempt to find them the previous day was not successful. Armed with detailed directions from the B&B owners, however, we decided to give it one more shot. Again, even after we found the site I didn’t see them immediately, I suppose because I was expecting to see distinct depressions in dry, solid rock. Only after the reflections of light from an alternating series of small puddles—each measuring a good 10–12″ in diameter—did I realize we had found them. Recent rains had left the normally dry creek bed filled with mud, with the footprints themselves still filled with water.

Dinosaur tracks | vic. Black Mesa, Oklahoma.

Dinosaur tracks | vic. Black Mesa, Oklahoma.

It is not surprising that I would be so excited to find the tracks, but what did surprise me was the effect they had on me. Seeing the actual signs of near mythical beasts that lived an incomprehensible 100 million years ago invites contemplation and reminds us that our time here on Earth has, indeed, been short!

Dinosaur tracks | vic. Black Mesa, Oklahoma.

Dinosaur tracks | vic. Black Mesa, Oklahoma.

By this time, we had no choice but to succumb to the long drive ahead. We did manage to carve out a short stop at the very first locality of the trip in an effort to find more Buprestis confluens (finding only a few more B. rufipes), but otherwise the day was spent adhering to our goal of reaching Wichita before nightfall. Jeff was home and sipping tea before lunchtime the next day, while I endured one more solid day of driving before making it back to St. Louis in time for dinner with the family. At that point, the trip already could have been considered a success, but how successful it ultimately ends up being depends on what beetles emerge during the next season or two from these batches of infested wood that I collected at the various spots we visited.

Wood collected for rearing wood-boring beetles.

Wood collected for rearing wood-boring beetles.

If you like this Collecting Trip iReport, you might also like the iReports that I posted for my 2013 Oklahoma and 2013 Great Basin collecting trips as well.

© Ted C. MacRae 2014

Big, black (and red), and beautiful!

While I may have already declared Plinthocoelium suaveolens (bumelia borer) as North America’s most beautiful longhorned beetle, any short list of top candidates for this title must also include the species Crossidius coralinus. Like most other members of this strictly North American genus, these gorgeous beetles emerge as adults during late August and September to feed on the profusion of yellow blooms put forth by their larval host plants, Ericameria nauseosa (gray rabbitbrush). Across the Great Basin and adjacent areas, the relatively large size, spectacularly long antennae, and stunning value contrast between red/black or orange/black beetles, yellow flowers, and blue skies combine to make the sight of C. coralinus a highlight on any fall insect collecting trip. If beauty alone isn’t enough, the species also exhibits an unusual level of polytopism across its range. Red in some areas (e.g., C. c. temprans), orange in others (e.g., C. c. monoensis), bigger or smaller, and varying degrees of development of the black areas that cover the basal edge and apical portion of the elytra, the species segregates into several described subspecies and many more unnamed but locally distinct populations. This post features photos of individuals from several populations that field-mate Jeff Huether and I encountered during last August’s Great Basin collecting trip.

Crossidius coralinus coralinus

Crossidius coralinus ssp. coralinus (male) | Montezuma Co., Colorado

Crossidius coralinus coralinus

Crossidius coralinus ssp. coralinus (female) | Montezuma Co., Colorado

One of the most impressive populations I’ve encountered is illustrated by the male and female individuals shown in the above photos, which were seen near the city of Cortez in southwestern Colorado. Linsley & Chemsak (1961) assigned specimens from this area to the nominate subspecies, characterizing them as “moderate-sized”; however, some of the individuals that we encountered at this site were truly gargantuan (exceeding 20 mm in length). Note how extensive the black areas are in these individuals, especially the female.

Crossidius coralinus jocosus (male) | Costilla Co., Colorado

Crossidius coralinus ssp. jocosus (female?) | Costilla Co., Colorado

Crossidius coralinus jocosus (female) | Costilla Co., Colorado

Crossidius coralinus ssp. jocosus (female) | Costilla Co., Colorado

On the other side of the state near Fort Garland (southeastern Colorado) we encountered a population that Linsley & Chemsak (1961) considered representative of the subspecies C. c. jocosus. In contrast to the larger size and extensive black markings of the nominotypical population we found near Cortez, individuals in this population were considerably smaller in size and exhibited less extensively developed black areas of the elytra. Their small size also made them a little harder to notice—perhaps that is the reason we found so few individuals (~7 total at several sites along Hwy 160). We did note also, however, that the gray rabbitbrush flowers seemed to be well past their prime, so perhaps an earlier appearance of the rains upon which plant flowering and beetle emergence rely had us on the tail end of their activity period.

Crossidius coralinus coralinus

Crossidius coralinus ssp.? (male) | San Juan Co., Utah

Crossidius coralinus coralinus

Crossidius coralinus ssp.? (female) | San Juan Co., Utah

Linsley & Chemsak (1961) noted several populations across middle and southern Utah, but the only one to which they assigned a name was C. c. coccineus in Washington Co. (southwestern Utah). While we didn’t visit Washington Co. on this trip, we did look for these beetles at several sites north of Monticello in San Juan Co. (southeastern part of the state). Geography would place this population close to nominotypical populations, and while the beetles in this population resembled them in size they clearly differed in the greatly reduced black areas of the elytra. Note the male especially, with the black area reduced to little more than a sutural stripe in the apical half of the elytra. Linsley & Chemsak (1961) related specimens collected just a few miles further south from ours to an unnamed population in adjacent Wayne Co. (near Hanksville), both of which seem to be close to C. c. coccineus due to their robust size and the reduced black elytral markings of the male.

Crossidius coralinus ssp. (female) | Nye Co., Nevada

Crossidius coralinus ssp.? (female) | Nye Co., Nevada

Crossidius coralinus is found commonly along the western edge of the Great Basin in the form of C. c. temprans. However, Linsley & Chemsak (1961) presented very few records of the species further east in Nevada. We stopped at several spots in central Nevada while traveling along Hwy 6, but despite an abundance of gray rabbitbrush stands in peak bloom we found but a single male and a single female, the latter shown in the above photograph. Geographically this female should be assignable to C. c. temprans, but the black area of the elytra is not nearly so expanded as is typical for that subspecies. The only record from central Nevada in Linsley & Chemsak (1961) is a single male from White Pine Co. (a little further to the east), but they related that specimen to an unnamed population near Marysvale in Piute Co., Utah of smaller size and with the black area of the elytra distinctly expanded in both sexes.

The author photographing insects on flower head of Ericameria nauseosus.

The author photographs insects on gray rabbitbrush in San Juan Co., Utah.

There are those who say “Subspecies, schmubspecies!” I concede they may be right for a large number of named subspecies, possibly including C. coralinus, and while the basin and range topology of the Great Basin and discontinuous distribution of host plants within that geography provide ideal conditions for the development of distinctive, geographically based populations, I suspect C. coralinus has sufficient mobility to allow gene flow across its range (with the possible exception of populations in California’s Central and Owens Valleys). Moreover, the inability of Linsley & Chemsak (1961) to segregate the central Great Basin populations into discrete taxonomic units suggests that the subspecies concept may not be applicable. Nevertheless, it cannot be denied that distinctive, localized populations of this species do exist. Moreover, I hesitate to dismiss subspecies in problematic taxa such as C. coralinus, because doing so makes it easier to ignore variability and presume (possibly incorrectly) no geographic component. Variability is interesting and should be thoroughly evaluated to determine its basis regardless of its basis. Geographically based variability is especially interesting because it suggests the existence of distinct genetic traits that contribute to the genetic diversity of species. Such traits are valuable to protect, and the use of subspecies provides a convenient shorthand for referring to the populations that contain them in both taxonomic and conservation contexts.

REFERENCE:

Linsley, E. G. & J. A. Chemsak. 1961. A distributional and taxonomic study of the genus Crossidius (Coleoptera, Cerambycidae). Miscellaneous Publications of the Entomological Society of America 3(2):25–64 + 3 color plates.

© Ted C. MacRae 2014

When is a stag beetle not a stag beetle?

A: When it’s a longhorned beetle!

Parandra (Tavandra) polita

Parandra (Tavandra) polita | Alexander Co., Illinois

Last week I traveled to northwestern Tennessee to visit research plots, and on the way back I took the opportunity to stop by Fort Defiance Park near Cairo, Illinois. Fort Defiance represents the southernmost tip of Illinois, lying at the confluence of the Ohio and Mississippi Rivers, and on previous visits I had thought that the wet bottomland forest remnants present there looked like promising habitat for the ant-like tiger beetle (Cylindera cursitans). The type locality of a synonym (Cicindela alata) is in northern Illinois, but the type specimens are considered to have been introduced and, to my knowledge, no bona fide records of the species are known from the southern part of the state. I have taken the species nearby on the Missouri side of the Mississippi River (MacRae et al. 2011), so I thought the chances were good of finding it here as well. And find it I did—in good numbers! Success already in hand, I decided to stick around for nightfall and set up some blacklights to see what other beetles might be attracted from the surrounding forests.

Parandra (Tavandra) polita

The color and shape of the body and prominent jaws give the appearance of a small stag beetle.

Sadly, not much of interest was coming to the lights. Temperatures and humidity were good, but a waxing moon with clear skies didn’t help. Worse, the sheets were inundated with caddisflies—always a predictable consequence when blacklighting near large rivers but especially annoying because of their habit of flying into your face (and up nostrils, down shirts, in ears…) when checking the sheet for other insects. A few longhorned beetles did show up, as did some male and female reddish-brown stag beetles (Lucanus capreolus), and later a single coppery tiger beetle (Ellipsoptera cuprascens) also made an appearance. By 10 pm, however, I had decided enough was enough and went to one of the sheets to begin taking it down. As I did, I noticed a reddish-brown, large-mandibled beetle sitting on the sheet that, for all intents and purposes, looked like a small stag beetle. I wasn’t fooled, however, as I knew exactly what this beetle was—I had previously seen this species in the form of two individuals at a blacklight in southern Missouri very near to my current location (although it was 28 years ago!). It was Parandra polita, an usual longhorned beetle belonging to the archaic subfamily Parandrinae, and those specimens (MacRae 1994) plus another collected more recently a few miles north—also at a blacklight in wet bottomland forest along the Mississippi River (McDowell & MacRae 2009)—to date represent the only known occurrences of this uncommon species in Missouri.

Parandra (Tavandra) polita

The entire rather than emarginate eyes distinguish this species from Neandra brunnea,

Linsley (1962) noted the tenebrionid (darkling beetle)-like appearance of beetles in this genus. Perhaps the glabrous, parallel-sided body recalls the appearance of some darkling beetles, but I have always thought these beetles looked more like stag beetles because of the reddish-brown coloration and, notably, fairly large, forward-projecting mandibles that even show the same type of size dimorphism as stag beetles—larger in “major” males, smaller in females and “minor” males. Parandrines differ from most other subfamilies of longhorned beetles by having the antennae short and equal-segmented and the tarsi distinctly pentamerous with slender, padless segments. Another small subfamily of longhorned beetles, the Spondylidinae, shares these characters, but parandrines are easily distinguished from them by several characters including the margined pronotum—also a most lucanid-like character.

Parandra (Tavandra) polita

Parandra polita also has the mandibles contiguous at the base and a narrower, more flattened body.

Although Parandrines are reasonably diverse in South America and Africa, North America boasts only four taxa, with P. polita and Neandra brunnea being the only two occurring in the eastern part of the continent. Annoyingly, I have collected just as few specimens of the latter as the former, despite the fact that N. brunnea is considered to be the most commonly encountered of all four North American taxa. The specimens were all taken in Japanese beetle traps that I ran while working for the Missouri Department of Agriculture in the 1980s, so I have never actually seen a live individual of that species. Parandra polita and N. brunnea are, however, fairly easy to distinguish, as the former has the mandibles triangular and contiguous at the base while in the latter they are sickle-shaped and well separated at the base. The former also has the eyes entire on the inner margin while the latter has them distinctly emarginate, and in basic gestalt P. polita has a narrower, more flattened body than N. brunnea.

A frontal portrait of this beetle was featured a few days ago in ID Challenge #23. A few people were fooled by its lucanid- and even cucujid-like appearance, but Stephen, Harry Zirlin, Nikola Rahme, Jon Quist, and Ben Coulter all correctly guessed this species. By virtue of being first, Stephen rises above the 5-way tie to get the win. However, I should note that Harry was the first to actually provide names for each of the four requested taxa (as did Jon and Ben subsequently), so he could make a valid claim for the win. Also, nfldkings and froglady made really nice comments about my blog and the featured photo, so I award them with honorable mentions!

REFERENCES:

Linsley, E. G. 1962. The Cerambycidae of North America. Part II. Taxonomy and classification of the Parandrinae, Prioninae, Spndylinae, and Aseminae. University of California Publications in Entomology 19:1–102, 1 plate [OCLC WorldCat].

MacRae, T. C. 1994. Annotated checklist of the longhorned beetles (Coleoptera: Cerambycidae and Disteniidae) known to occur in Missouri. Insecta Mundi 7(4) (1993):223–252 [pdf].

MacRae, T. C., C. R. Brown & K. Fothergill. 2011. Distribution, seasonal occurrence and conservation status of Cylindera (s. str.) cursitans (LeConte) (Coleoptera: Cicindelidae) in Missouri.  CICINDELA 43(3):59–74 [pdf].

McDowell, W. T. & T. C. MacRae. 2009. First record of Typocerus deceptus Knull, 1929 (Coleoptera: Cerambycidae) in Missouri, with notes on additional species from the state. The Pan-Pacific Entomologist 84(4) (2008):341-343 [pdf].

© Ted C. MacRae 2014

One-shot Wednesday: Mallodon dasystomus

Mallodon dasystomus | southeast Missouri (Mississippi Co.)

Mallodon dasystomus | southeast Missouri (Mississippi Co.)

Today’s (slightly belated) edition of “One-shot Wednesday” features a beetle that I saw just about this time last year while blacklighting along the Mississippi River in the southeastern lowlands of Missouri. Mallodon dasystomus¹ is a prionid longhorned beetle (family Cerambycidae, subfamily Prioninae) that is sometimes called the “hardwood stump borer”. It is perhaps one of the most widely distributed members of its group, occurring across the southern tier of the U.S. down through Mexico and Central America as far as northern South America.

¹ Until recently the specific epithet was consistently misspelled in most of the literature as “dasytomus“. A closer look at the Greek root words dasus (δασύς), meaning “hairy”, and stoma (στόμα), meaning “mouth”, shows the misspelling to be nonsensical. I, myself, am guilty of using the wrong spelling in my checklist of Missouri longhorned beetles (MacRae 1994), although I can claim to have been “going with the flow”.

Despite the beetle’s wide geographical range, I searched for it both eagerly and unsuccessfully during the 1980s as I was gathering data for my checklist of Missouri longhorned beetles (MacRae 1994). I eventually published that checklist and included the species on the basis of a few specimens seen in other collections, but I never encountered it for myself until some years later during a visit to Cave Creek Canyon in southeast Arizona. As noted by Linsley et al. (1961), this species is common there and is associated with large, partially dead Arizona sycamores (Platanus wrightii). Although nearly 20 years ago, I still recall seeing the large beetles crawling high up on the trunks and sitting in their emergence holes with only their massively-mandibled heads protruding as they tantalizingly waved their antennae about.

That experience would directly lead to my eventually finding this species for myself in Missouri. Shortly after returning to the state in the mid-90s, I was driving along a road in the state’s southeastern lowlands when I passed a very large, half-dead American sycamore (Platanus occidentalis). Even at a speed of 40 mph I could see the large emergence holes that immediately reminded me of what I had seen in Arizona, so I hit the brakes, made a quick U-turn, and came back to look at the tree a little more closely. I was convinced the holes were made by this species, and my hunch was proven when I eventually found several beetle carcasses on the ground around the base of the tree. I returned the following weekend with a chainsaw, cut several one-cubic-foot sections of wood from the dead portion of the massive tree’s trunk (with landowner permission), and eventually reared a nice series of adults from the wood. Having uncovered the association of this species with sycamore in the state, I was able to find the species also in several other locations in southeastern Missouri, but I have not managed to find the species in any areas north of the southeastern lowlands in Missouri despite the common occurrence of the host tree.

The beetle in the above photograph landed on the foliage of a large silver maple (Acer saccharinum) next to the ultraviolet light I had setup in wet bottomland forest along the Mississippi River, and wanting to ensure that I got at least one in situ photo of the beetle that is where I shot it. I did try to move it to the trunk of a large, dead sycamore nearby for a more realistically representative photo of how these beetles are usually encountered, but the beetle became quite agitated when I moved it and my considerable patience was never rewarded. I popped it into a vial in hopes of photographs the next morning, but conditions were not to the beetle’s liking and it expired before I had another chance to photograph it. Just the other night I setup a blacklight in a spot not too far from where I saw this beetle in hopes of getting another chance to photograph it. That effort was not successful, but I did find a longhorned beetle species that I had not seen in nearly 30 years! I was successful in photographing that species but (please excuse the teaser) will save those photos for a future post.

REFERENCES:

Linsley, E. G., J. N. Knull & M. Statham. 1961. A List of Cerambycidae from the Chiricahua Mountain Area, Cochise County, Arizona (Coleoptera). American Museum Novitates 2050:1–34 [full text, pdf].

MacRae, T. C. 1994. Annotated checklist of the longhorned beetles (Coleoptera: Cerambycidae and Disteniidae) known to occur in Missouri. Insecta Mundi 7(4) (1993):223–252 [pdf].

© Ted C. MacRae 2014

Black is beautiful!

Most species in the genus Crossidius exhibit varying amounts of yellow/red/orange coloration on the body. However, one species—Crossidius ater—dispenses with such adornments and remains all-black throughout its expansive range across the Great Basin and surrounding areas. Despite this, they are no less pretty than their more gaudily colored relatives. The adults in these photos were seen on flowers of yellow rabbitbrush (Chrysothamnus viscidiflorus) at two locations in White Pine County, Nevada on 30 August 2013 (all photos w/ natural sky background).

Crossidius ater | 7.2 mi SW NV318 on US6, White Pine Co., Nevada.

Crossidius ater | 7.2 mi SW NV318 on US6, White Pine Co., Nevada.

Crossidius ater | Ely,  1.2 mi S Jct US6/50/93, White Pine Co., Nevada.

Crossidius ater | Ely, 1.2 mi S Jct US6/50/93, White Pine Co., Nevada.

Crossidius ater | Ely,  1.2 mi S Jct US6/50/93, White Pine Co., Nevada.

Crossidius ater | Ely, 1.2 mi S Jct US6/50/93, White Pine Co., Nevada.

© Ted C. MacRae 2014

A Crossidius hirtipes subspecies blend zone…

…or, “There’s something fishy going on here!”

After a day in the vicinity of Yearington, Nevada  looking for (and eventually finding) a population of Crossidius hirtipes longhorned beetles assignable to subspecies “rubrescens“, field mate Jeff Huether and I dropped a little further south to look for two additional subspecies—C. h. immaculipennis and C. h. macswaini. Like C. h. rubrescens, populations assignable to these two subspecies are also restricted to a small area in west-central Nevada. Chemsak & Linsley (1959) described C. h. immaculipennis from specimens collected 10 miles north of Smith (Lyon Co.) and two years later (Linsley & Chemsak 1961) described C. h. macswaini from 19 miles SE of Wellington (Douglas Co.). We were still under the smoke plum from the now 9-day old Rim Fire in the nearby Sierra Nevada, which came and went during much of the day (top photo) and eventually settled in to create some amazing sunset landscapes (bottom photo).

19 mi S of Wellington, Toiyabe National Forest, Nevada.

Rim Fire smoke moves in and out of the area | 19 mi S of Wellington, Toiyabe National Forest, Nevada.

As had happened the day before with C. h. rubrescens, success did not come quickly or easily. We first searched for the type locality of C. h. immaculipennis, but many parts of the area have been converted to agriculture, and in the precise area 10 miles north of Smith we found only vast fields of dark green, irrigated alfalfa and not the rabbitbrush chaparral habitat required by these beetles. We did a little searching in surrounding areas and eventually found one rather nice-looking patch of ground with healthy stands of Chrysothamnus viscidiflorus in full bloom. Mindful of the previous day’s experience with finding the beetles often ensconced down within the inflorescences—especially as cooler temperatures set in, we took care to carefully inspect the blossoms in case the cool morning temperatures were inhibiting the beetles from coming back up for the day. Alas, we saw no beetles despite spending a considerable amount of time searching.

Crossidius hirtipes immaculipennis (male) | 6.3 mi W of Wellington, Nevada.

Crossidius hirtipes immaculipennis (male) | 6.3 mi W of Wellington, Nevada.

Rather than beat a dead horse, we decided to drive a short distance south and west to the town of Wellington, where a fellow cerambycid collector had found the subspecies a few years earlier. He had provided us with some detailed notes on the specific localities where he found the beetles, and these proved to be of great help as we passed through endless, seemingly acceptable chaparral habitat trying to decide exactly where we should stop and invest more time to look for the beetle. We stopped at one of the sites indicated in the notes and immediately found a beetle on one of the first plants we checked, and eventually after a gap in finding any more we found an area where good numbers of the plants were supporting decent numbers of the beetles. Chemsak & Linsley (1959) distinguished C. h. immaculipennis by its reddish legs, pale color, and complete lack of elytral markings in the male, exemplified by the male shown in the photo above.

Crossidius hirtipes macswainei? (female) | 6.3 mi W of Wellington, Nevada.

Crossidius hirtipes macswainei? (female) | 6.3 mi W of Wellington, Nevada.

As we searched the plants and found more and more individuals, I noticed an occasional adult that seemed to be a little more yellowish than reddish and with distinct sutural maculae. I didn’t think much about it then, chalking it up to individual variability, but after returning home and having a chance to look at the specimens more closely I was surprised to determine that these few beetles actually are a better fit for the second subspecies we planned to search for that day—C. h. macswainei. We had found both subspecies at the same site and didn’t even realize it. Okay, I know what you’re thinking… subspecies must exhibit allopatric geographic distributions (cannot occur together at the same place and time). It is, thus, tempting to declare that the two “subspecies” are actually not distinct, but rather represent distinctive extremes of individual variation in a single interbreeding population. However, one must also consider the possibility that the two subspecies represent reproductively isolated populations and, thus, qualify as distinct species. I’m not qualified to make that judgement, but I will note that most of the individuals encountered were assignable to C. h. immaculipennis  and the rest to C. h. macswainei, but that no “intergrades” were found.

Crossidius hirtipes macswainei (male) | 19 mi S of Wellington, Nevada.

Crossidius hirtipes rhodopus? (male) | 19 mi S of Wellington, Nevada.

After collecting adequate series from W of Wellington, we traveled further south of town to the type locality of C. h. macswainei (not knowing we already had it!). The holotype and most of the paratypes were collected 19 miles S of Wellington (Linsley & Chemsak 1961), but a number of paratypes had also been collected 14 miles south of town, so we stopped there first in an unsuccessful bid to find the subspecies before moving on to the type locality a few miles further south. Within a few minutes of arriving, I found the individual shown in the photo immediately above, presumed that I had found the subspecies we were looking for, and popped it into a vial alive as a photo backup if we did not find any other individuals with which I could attempt field photographs. Ironically, that is exactly what happened—despite Jeff and I scouring every plant we could find in about a 1-mile stretch along each side of the road, we never found another beetle. Later that evening I took the above individual out of its vial for photographs, but it never really “perked up” to look fully natural, resulting in “bum” antennae that give away the staged nature of the photograph. Again, it was not until I got back home and could look at the specimen closely before I realized that it did not at all fit the description of C. h. macswainei, but instead seemed to be a good match for the subspecies C. h. rhodopus, known from only a short distance further south but—until now, at least—apparently restricted to the Mono Basin in east-central California (see this post for more details about this subspecies). Jeff has since reported to me that some of the beetles he collected at the “C. h. rubrescens” locality (see this post) also are a match for C. h. macswainei, adding yet another wrinkle to those that resulted from this day’s collecting. Such inconsistencies with the published literature may tempt some to scrap all of Linsley & Chemsak’s subspecies, but considering that those two authors examined more than 12,000 specimens during the course of their studies such a reaction would be both premature and presumptuous. What is needed is more study—more specimens from more localities, hopefully augmented with DNA sequence analysis. For the latter goal we did our part, dropping a specimen or two from every locality in which we found beetles into ethanol for just such purpose. Until such studies are done, I prefer to withhold judgement about whether C. hirtipes is comprised of one highly polytopic population, several subspecifically distinct populations, or perhaps even multiple distinct species.

14 mi SE of Wellington, Toiyabe National Forest, Nevada.

Evening haze creates a spectacular sunset | 14 mi SE of Wellington, Toiyabe National Forest, Nevada.

Even though we found only a single beetle at the second locality, our persistence in searching until the day ran out was rewarded by a most spectacular sunset caused by thick haze from the nearby Rim Fire in California. It would also be our last day in Nevada before dropping south into California and spending the next several days in successful bids for C. coralinus monoensisC. c. caeruleipennisC. h. nubilus, and C. h. rhodopus.

REFERENCE:

Chemsak, J. A. & E. G. Linsley. 1959. Some new species and subspecies of Crossidius from western North America. Journal of the Kansas Entomological Society 32(4):176–183.

Linsley, E. G. & J. A. Chemsak. 1961. A distributional and taxonomic study of the genus Crossidius (Coleoptera, Cerambycidae). Miscellaneous Publications of the Entomological Society of America 3(2):25–64 + 3 color plates.

Copyright © Ted C. MacRae 2014