Arthropoda

Arthropods – insects, arachnids, crustaceans, myriapods, & relatives

Wasp Wednesday—Not!

/ Ted C. MacRae / 6 Comments

In early September, the agricultural landscape in the central U.S. awakens from its monotonous cloak of summer green and turns ablaze with a hundred shades of yellow, gold, and tawny. The “fall composites” as they are commonly called, a dazzling diversity of mostly yellow-flowered herbaceous plants in the family Asteraceae, are one of the chief contributors to this explosion of color, and among them none contribute more than goldenrod (Solidago sp.). Occupying nearly every fence row, drainage ditch, and fallow field, the bright yellow fronds of tiny flowers are not only pleasing to the eyes of humans, but a smorgasbord of pollen for all manner of flower-feeding insects. Bees, flies, wasps, beetles, and moths all flock to the bounty in numbers rarely seen during the dog days of summer. Spiders, ambush bugs, mantids, and other predators take up residence amongst the flowers as well—not to feed on the flowers, but rather the abundance of flower-feeding insects upon which they will prey. It is rare to find a goldenrod plant without at least a few insects upon it.

Synanthedon decipiens (oak gall borer) on Solidago sp. | Mississippi Co., Missouri

My favorite goldenrod insects are, of course, the longhorned beetles of the genus Megacyllene, and at least here in Missouri there are none finer than Megacyllene decora (see A classic fall ‘bycid). However, I keep an eye out for other insects as well, and when I first saw this “wasp” sitting on a flower head I had to do a bit of a double take—”something” just didn’t seem quite right about it. A little lean forward was all that was needed to confirm that this was indeed no wasp, but rather a clearwing moth (order Lepidoptera, family Sesiidae)¹. To my mind, of the many insects that try to mimic wasps, none do so more effectively than members of this family. From the elongate body to the yellow abdominal banding and narrow transparent wings, everything about this moth says “wasp”—well, almost everything or I wouldn’t have done a double take to begin with.

¹ I hope Eric Eaton, author of Bug Eric and its Wasp Wednesday series, will forgive my use of his title for this post.

Apparently a male, these moths use pheromones to locate females for mating.

I actually did a fair bit of work with this group in my early years with the Department of Agriculture. Females of most (all?) species emit species-specific pheromone blends that males can detect at incredibly low volumes (only a few molecules are needed to elicit a response by the male antenna). Components of these pheromones have been synthesized, and since a number of species have economic importance in landscape and nursery settings (larvae of most species are borers of woody or perennial plants), these synthetic pheromone blends are commonly employed in traps for survey and detection (e.g., Snow et al. 1985). I conducted surveys for several years during the mid 1980’s in east-central Missouri using these traps and, thus, developed a good eye for distinguishing these moths in flight from the wasps that they so effectively mimic. In fact, I used to keep a pheromone tag on my waist bag, which resulted in male moths frequently flying up to me and “searching” for the female. I never tired of seeing the faces of nursery growers—first showing concern as they were convinced I was under attack by a wasp, and then shock as I calmly reached out and grabbed the “wasp” in mid-flight with my bare hand! (And to be perfectly honest, it took me a while before I could bring myself to start grabbing them out of the air!) I even had one nursery grower continue insisting it was a wasp and could sting even after I had caught it (“Naw, them things sting—I seen ’em!)

The moth in these photos seems to best match Synanthdedon decipiens, widely distributed east of the Rockies and inhabiting the woody galls of cynipid wasps on oaks. In Georgia adults of this species exhibit a bimodal pattern of seasonal occurrence suggestive of two generations per year (Snow et al. 1985), so this September-occurring male might represent a second Missouri generation as well.

REFERENCES:

Snow, J. W., T. D. Eichlin & J. H. Tumlinson. 1985. Seasonal captures of clearwing moths (Sesiidae) in traps baited with various formulations of 3,13-0ctadecadienyl acetate and alcohol. Journal of Agricultural Research 2(1):73–84.

Copyright © Ted C. MacRae 2012

Consolation Crossidius

/ Ted C. MacRae / 3 Comments

Rewind back to Day 2 of this year’s Annual Fall Tiger Beetle Trip at Gloss Mountain State Park in northwestern Oklahoma—these were actually the first non-Missouri beetles that I photographed on the trip. Crossidius pulchellus is a longhorned beetle (family Cerambycidae) that occurs commonly on flowers of broom snakeweed (Gutierrezia sarothrae) and relatives throughout the Great Plains and southern Rocky Mountains.

Crossidius pulchellus on flowers of Gutierrezia sarothrae | Major Co., Oklahoma. The dense vestiture (covering of hairs) of the beetles is made more conspicuous by backlighting the beetles with the sun.

I find it rather ironic that Crossidius pulchellus was the first western beetle that I encountered, since my original plans for this year’s late-season trip centered on looking specifically for longhorned beetles in the genus Crossidius (see last year’s Crossidius coralinus fulgidus for an extraordinarily beautiful representative of this genus). Unlike the vast majority of the family that develop as larvae in dead wood, species in this diverse, exclusively western North American genus bore through the roots living, perennial shrubs belonging to the genera Gutierrezia, Chrysothamnus/Ericameria, and Haplopappus (family Asteraceae)—the “goldenrods” of the west, they bloom in widespread, yellow-flowered profusion as summer turns to fall. A wide variety of insects are attracted to these blooms, most of which—bees, flies, wasps, moths, etc.—are opportunistic pollinators. Crossidius beetles, however, are intimately associated with the plants, seemingly spending their entire, brief adult lives either perched, feeding, or mating upon the flowers. Even at night, rather than leaving the plants to search for protected hiding spots, they simply bury themselves deeper amongst the flowers and await the next morning’s first, warming rays of sunlight.

Sampling the diversity of Crossidius that springs forth each year across the west requires carefully timed travel to multiple localities spread widely across rough terrain. As longhorned beetles go, the genus exhibits an astounding level of polytopism (geographically-based variation) that in many respects resembles that exhibited by North American tiger beetles. This has resulted in the description of a relatively large number of species, most of which can be further divided into numerous recognizable subspecies and even local morphs. The discontinuous distribution of their host plants across the broken western topography and resulting isolation of local populations have contributed to this variability, further complicated by hybridization among species occurring together in a given locality (Linsley & Chemsak 1961). I got a taste of the diversity of these beetles during last year’s fall tiger beetle trip as I looped through Colorado, Idaho, and Utah. Although my plans to look for them this year didn’t work out, my appetite remains whetted. There is always next year!

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):26–64, 3 color plates.

An uncommon fall-active Acmaeodera

/ Ted C. MacRae / 3 Comments

During last week’s visit to Alabaster Caverns State Park in northeastern Oklahoma (Woodward Co.), I saw a fair number of jewel beetles (family Buprestidae) representing a then-unidentified species of Acmaeodera. All of the individuals that I saw were visiting flowers of Heterotheca stenophylla (family Asteraceae), and had it not been fall I wouldn’t have thought much about it. However, fall activity is unusual among North American jewel beetles, particularly in the genus Acmaeodera. An occasional straggler from earlier in the season is one thing, but the numbers seen (perhaps close to two dozen) over the course of a couple hours left no doubt in my mind that these were newly active adults. In North America, most species of Acmaeodera are active during the spring and early summer months, during which time they visit a wide variety of flowers (but especially asteraceous species) to feed on pollen. They can also be found in late summer in southeast Arizona, but in that area nearly all jewel beetles (and a large number of other insect groups as well) occur in synchrony with the monsoonal season that begins in July. Only in southern Texas (and further south in México) have I seen truly fall-active jewel beetles, including several species of Acmaeodera.

This actually was not the first time I had seen this species during fall in Oklahoma. Last year I made a brief stop at Gloss Mountain State Park (about 30 miles southeast of Alabaster Caverns in Major Co.) on my way back from a late September collecting trip to Colorado/Utah/Idaho (still convinced that the Beautiful Tiger Beetle, Cicindela pulchra, might be there). Then, as now, I found more than a handful of adults (also visiting flowers of H. stenophylla), suggesting this was true fall activity and causing me to think, “Hmm, that’s weird.” I was pressed for time, however, and didn’t even grab my camera bag for the short hour or so that I had to look around, and once I returned home I quickly resumed my routine and forgot about trying to identify the beetles.

Acmaeodera macra | Woodward Co., Oklahoma

Returning home after this year’s trip I was not so inclined to forget, and when I mentioned it to my friend Chuck Bellamy he suggested that it might be the fall-active species, Acmaeodera macra (MCZ type specimen). Immediately I knew this was correct, as I had actually seen this species once before—a single specimen that I collected nearly 30 years ago  in south Texas at Bentsen-Rio Grandy Valley State Park on a Helianthus annuus flower (MacRae 2006). I don’t know why I didn’t think of that species when I saw it this time, other than perhaps I was still under the impression that this uncommonly encountered species was limited to the Rio Grande Valley and adjacent areas as stated by Vogt (1949) and Westcott et al. (1979). Recently, however, Westcott (2001) provided the first records of this species from outside of Texas—from Oklahoma!—and later recorded it also from Nuevo León, México (Westcott 2008).¹

¹ Nelson et al. (2008), in their North American catalogue of Buprestidae, also list Arizona in the distribution of this species. However, I am unaware of any supporting references for its occurrence there, and the catalogue is known to be frustratingly rife with errors and omissions. 

Bathed in pollen!

The Oklahoma records for this species given by Westcott (2001) include localities in Blaine, Cleveland, Greer, and Oklahoma Counties (with the latter taken on Grindelia sp., presumably flowers). Interestingly, with the exception of Greer Co. all of these counties lie along the Blaine Escarpment that separates the Gypsum Hills and Red Hills physiographic regions, and the two additional counties that I have now recorded for the species in Oklahoma (Major and Woodward) lie further to the north along this escarpment as well. With these new records, Alabaster Caverns now becomes the northernmost known outpost for A. macra. However, since Woodward Co. lies along the northern tier of counties in Oklahoma and the Blaine Escarpment extends further into south-central Kansas, it is possible that an even more northern outpost might eventually be found for the species. Little is known about the biology of this species—the only host records are for adults and include my sunflower record (MacRae 2006), Vogt’s (1949) mention of the species’ preference for “composite flowers” and records of adults on Acacia berlandieri and visiting flowers of Verbesina encelioides (Westcott et al. 1979). It’s anybody’s guess as to what the larval host is, but my guess is that in Oklahoma it’s restricted to vertical walls and talus slopes, since I never saw individuals outside of these specific situations despite the widespread occurrence of its H. stenophylla flower host.

REFERENCES:

MacRae, T. C. 2006. Distributional and biological notes on North American Buprestidae (Coleoptera), with comments on variation in Anthaxia (Haplanthaxia) viridicornis (Say) and A. (H.) viridfrons Gory. The Pan-Pacific Entomologist 82(2):166–199.

Nelson, G. H., G. C. Walters, Jr., R. D. Haines, & C. L. Bellamy.  2008.  A Catalogue and Bibliography of the Buprestoidea of American North of Mexico.  Coleopterists Society Special Publication No. 4, The Coleopterists Society, North Potomac, Maryland, 274 pp.

Vogt, G. H. 1949. A biologically annotated list of the Buprestidae of the Lower Rio Grande Valley, Texas. Annals of the Entomological Society of America 42(2): 192–202.

Westcott, R. L. 2001.  An interspecific hybrid in the genus Acmaeodera Eschscholta, a taxonomic note on Chrysobothris kelloggi Knull, and new distribution and host records for United States and Canadian species in these and other genera (Coleoptera: Buprestidae).  Jewel Beetles, 10:76-81.

Westcott, R. L., W. F. Barr, G. H. Nelson, & D. S. Verity.  1979.  Distributional and biological notes notes on North and Central American species of Acmaeodera (Coleoptera: Buprestidae).  The Coleopterists Bulletin, 33(2):169-181.

Copyright © Ted C. MacRae 2012

Photographing the Limestone Tiger Beetle

/ Ted C. MacRae / 9 Comments

Seeing and photographing the beautifully black Prairie Tiger Beetles (Cicindelidia obsoleta vulturina) in southwestern Oklahoma was a lot of fun, but by Day 5 I was ready to look for one of my top goals for the trip—Cicindelidia politula (Limestone Tiger Beetle). Occurring primarily in Texas (but also sneaking up into Oklahoma), this would be my first attempt to search for the species. I had gotten a few localities in northern Texas from trusty colleagues, and I knew the beetles occurred on limestone outcroppings in dry to xeric upland habitats (Pearson et al. 2006)—usually starting in late September.  Nevertheless, I always get a little apprehensive when I drive long distances to look for tiger beetles I’ve never seen before. Will I recognize it? What if I find another, similar looking but more common species and assume I’ve found it? Will the season be right? Many species, especially those associated with xeric habitats, depend on timely rains to make their appearance. Will I find the proper microhabitat? There are sometimes seemingly minor details that can make a habitat suitable or not for a particular species.

Cicindelidia politula politula | Montague Co., Texas

As can be seen by the above photo, I did succeed in finding the species. However, it wasn’t easy, and for the better part of Day 5 I wondered if I would even be able to capture a specimen, much less succeed in photographing the species in its native habitat. I actually saw the first individual of this species in Oklahoma—sitting on the very first exposed limestone rock at the very first locality I went to. My rule for photographing tiger beetles that I’ve never seen before is to collect the first individual and keep it alive in a vial. In the event I never see another individual or fail in my attempts to photograph them in the field, the first individual becomes my voucher specimen and studio backup. Fortunately, I rarely have to resort to studio shots, but in this case I muffed my attempt to capture the specimen! I searched the locality for a good hour and never saw another one until I circled back to where I started, and there it was again (it just had to be the same one). Believe it or not, I muffed the capture attempt once again! That was my last chance at the Oklahoma site, so it was a rather dejected 2-hour drive south to Montague Co. in northern Texas—knowing that I’d seen it and had my shot at it (two shots, actually) but still found myself empty-handed.

A serviceable photo, but like most of confined individuals it suffers from lack of ”pizzazz.”

My luck improved in Montague Co., although not right away or that much when it did. I had just about given up at this second locality when I saw one. This time I used the stalk-and-slap technique followed by a quick pounce to seal down the net around its perimeter and prevent escape by the beetle (they are real good at quickly finding the tiniest gap between the net rim and the ground and then zipping away in a flash). This time I succeeded in capturing the beetle and thus had my voucher, but my pounce was a little too rough on the beetle, resulting in an extruded genital capsule. This made it completely unusable for photographs (imagine a big orange blob sticking out of the butt of the beetle—not good, photographically!). Of course, finding a beetle at the site caused me to spend more time searching, but I never saw another beetle there.

The shiny black to blue-black elytra with white markings absent or limited to the apices are characteristic for the species.

At this point I had a decision to make—if I drove to the next locality on my list (2-hour drive), I probably would not arrive with enough time before sunset to find beetles. I decided not to waste the remaining daylight and instead just bushwhack where I was to look for similar roadside habitats and drive on after sunset. I found another good habitat fairly quickly, and within minutes after starting the search I saw one—and missed it! But then I saw another one—and missed it, too! Now my confidence was shaken, as neither of the two techniques I use most commonly for capturing tiger beetles were working. When I used the “stalk-and-slap” method the beetles always found a gap on the rough, rocky ground and got away, and when I used the “tap-and-sweep” method the beetles would hunker down at first and then fly right after the net passed over them. I would miss a total of eight (eight!) beetles before I finally (finally!) caught one, and then I would miss three more beetles afterwards! That single beetle is shown in the above photographs, which were taken after placing the beetle on a large, flat limestone rock that I laid on the bed in my hotel room that night (carrying that huge limestone rock into the hotel room was an experience!).

I really dislike photographing confined insects. Even if one prepares a wholly natural looking set and manages to cajole the subject into standing still, they rarely look quite right. I do like the first photo in the series, just because it’s a well composed face shot, but I’m not so fond of the more ‘classic’ view of the beetle represented by the second photo. Technically it’s an adequate photo that shows the beetle and all of its salient characters; however, it lacks, well… oomph, because the beetle isn’t really doing anything—the photo tells no natural history story. Still, an adequate photo that lacks oomph is better than no photo at all, so I made the best of my opportunity to take studio shots of the one good beetle I had and hoped for better luck the next day.

Exposed limestone road bank in Johnson Co., Texas—perfect habitat for Cicindelidia politula

The next day brought the luck that I was looking for. I was close to the next locality on my list when I saw a road bank with exposed limestone that just seemed to call out, “Search me!” I stopped and began searching, and within a few minutes I saw the first beetle—and missed it! Arghhh, not again! I would actually miss a few more before I finally caught one, so by now my confidence was destroyed. It’s been a long since I’ve had this much trouble catching tiger beetles, and if I was having this much trouble catching them, how on earth could I even contemplate trying to photograph them. However, the nice thing about finding a spot where beetles are out in numbers is the opportunity to try again—practice makes perfect. I decided my previous attempts had all been a little too lackadaisical and started buckling down and really concentrating on my technique. Not surprisingly, I started having success in capturing the elusive beetles (tap-and-sweep worked best), and after a time I felt like I had a good enough feel for the beetle’s behavior to begin trying for field photographs.

Cicindelidia politula politula | Johnson Co., Texas

Not surprisingly, given how difficult they were to catch, this also proved to be one of the most difficult species of tiger beetle that I’ve ever tried to photograph. Like many other tiger beetles that live in hot, xeric, open habitats they were extremely wary and difficult to approach, a behavior that was exacerbated by the now midday sun. Their escape flights were not very far, but far enough that if I’d already gotten into a prone position I had to get up and start all over again. The task was made even more difficult by the hard, jagged, rough-edge rocks on which I had to lay and crawl—ouch! Several individuals are represented in the field photographs shown here, each of which I had to “work” for some amount of time before I was able to finally get close enough to start taking photos (and representing only a few of the many individuals that I actually spent time “working”). Usually, the first photos of an individual are never very good but start the process of getting the beetle accustomed to my presence and the periodic flash of light. Eventually, if I’m lucky, it settles down and resumes normal searching and thermoregulatory behaviors, and I can then get as close as I want and really work the angles for a variety of compositions. I no longer try to approach beetles from the ‘proper’ angle; they turn so much while moving about that it’s easier to just wait for them to assume desired angles as they move about and be ready to shoot when it happens. Field photography of unconfined tiger beetles in their native habitat is hard and time consuming, but the results are well worth the effort. Compare the staged photos of the Montague Co. individual with the field photos from Johnson Co. What marvelous displays of active beetles engaged in natural behaviors in their native habitat the latter represent!

By midday the adults start ”sun-facing” to minimize thermal exposure in their hot, xeric habitats.

After getting several good photos of the beetle in its habitat, I decided it was time to try for some really close photos and added a full set of extension tubes to the camera. A set of tubes with a 100mm macro lens provides close to 2X magnification, but it also reduces the available working distance—a real challenge with wary tiger beetles under a midday sun! I spent quite a bit of time trying to get close enough to take advantage of the additional magnification, but I wasn’t successful until I encountered the individual in the photos below shade-seeking at the base of a yucca plant. Shade-seeking beetles tend to stay put and not move as much (although they still rarely just sit there).

Shade-seeking is another strategy to avoid the midday heat.

I worked this beetle for several minutes and managed to get a number of shots, each closer than the previous and culminating in the nice portrait below.

The ”pièce de résistance”—Cicindelidia politula politula at 2X life size!

My photographic appetite now completely satiated, I spent the rest of the day searching for (and finding) additional localities for the species in the area. I found them more often associated with older, level exposures that had at least a small amount of vegetation. In contrast, newer or steeply sloped exposures or those completely devoid of vegetation rarely had beetles associated with them. I had now spent two days working on C. politula, but the results—both as a collector and as a photographer—made it time well spent. I felt like I “understood” the beetle. However, with only two days left in the trip, it was time to start working my way back towards Missouri and focusing on the few additional goals I still had for the trip.

REFERENCE:

Pearson, D. L., C. B. Knisley and C. J. Kazilek. 2006. A Field Guide to the Tiger Beetles of the United States and Canada. Oxford University Press, New York, 227 pp.

Copyright © Ted C. MacRae 2012

Inchworm, Inchworm, Oh So Small

/ Ted C. MacRae / Leave a comment

Soybean looper (Chrysodeixis includens) | 3rd-instar larva

Okay, I know this is not a real “inchworm” (generally restricted to caterpillars in the family Geometridae), but this young larva of a soybean looper (Chrysodeixis includens, family Noctuidae) is just too cute to not have an equally cute name. I believe it is an early 3rd instar, based on its small size (~7mm in length), lightly colored head capsule, and distinct bristles around the head and on the body—1st instars have a black head capsule, while 2nd instars have a light brown head capsule, and in both the bristles on the body are smaller and not as distinct.

This larva hatched from an egg laid on soybean by a laboratory-reared adult.

Copyright © Ted C. MacRae 2012

Dressed in black

/ Ted C. MacRae / 14 Comments

The first three days of this year’s Fall Tiger Beetle Trip had been fun, and finding a new state record jewel beetle and an unusual seasonal activity record for another were definitely icing on the cake. Still, tiger beetles (at least adults) had been notably absent, with my hunch that Cicindela pulchra (Beautiful Tiger Beetle) might occur in the Red Hills of northwestern Oklahoma not playing out. My next goal was to go down to northern Texas and look for Cicindelidia politula (Limestone Tiger Beetle)—a species I have not yet encountered in the field. When I saw that the route south took me through the Wichita Mountains of southwestern Oklahoma, I recalled seeing this photo of Cicindelidia obsoleta vulturina (Prairie Tiger Beetle) on BugGuide taken in these very mountains during the fall. I have seen on many occasions the greenish Missouri / Arkansas disjunct population of this subspecies, but I had not yet seen the main population and its decidedly black individuals, so this became my quarry for Day 4 of the trip. I had nothing more to go on for a locality than “Wichita Mountains NWR” and a sense of its habitat preferences based on my own experience with the MO/AR disjuncts, so after arriving at the refuge I began to look for access to a 2-track leading to higher, unforested ground (reminiscent of the dolomite glades of southwestern Missouri). I quickly found a parking lot with a 2-track leading from it, so I pulled off, geared up, and set out on what I figured was surely a wild goose chase. The track looked good, but no beetles were seen, and after walking about a half-mile I happened to look up and see this not too far ahead:

American bison | Wichita Mountains National Wildlife Refuge, Oklahoma

Call me chicken, but bison can and will charge without warning. Even though they seemed unconcerned by my presence, I wasn’t with anybody that I knew I could outrun 🙂 and decided that a cautious, tip-toeing retreat would the best course of action (even taking the above photo—uncropped, I might add—made me nervous). What now? I was quickly back at the car and not sure what to do next when I saw a foot path leading into a cedar woods, behind which the land rose up to treeless heights. I decided that might be a good place to explore—as long as I didn’t run into any bison along the way! As I was hiking through the woodland—an open, obviously long ago planted grove of eastern red cedar (Juniperus virginiana)—I passed by a small opening and almost by instinct veered into the opening to have a look. As soon as I stepped into the opening I saw the unmistakable escape flight of two large tiger beetles—what the…?! No doubt about it, they were C. o. vulturina, and they had been hanging out by a fairly fresh bovid chip (bison or cow, I don’t know). (I have seen this behavior also with the MO/AR disjuncts.) I watched them land and decided which one I would try to photograph. I guess I picked right, because the following photo was among the first few that I got:

Cicindelidia obsoleta vulturina (prairie tiger beetle) | Wichita Mountains National Wildlife Refuge, Oklahoma

Despite the jet-black dorsal surface (which contrasts with the green to greenish-black to bronzy dorsal surface of the MO/AR disjuncts), these were colorful beetles with gorgeous metallic blue genae (cheeks) and intense violaceous tibia (lower legs). This first individual was quite cooperative (usually it’s the tenth or more beetle that I try to photograph that actually allows me to do so), so I spent a bit of time trying to coax it back to the bovid chip from which it flew. Eventually I succeeded in this and took a few more photos, the following of which I liked the best:

Shade seeking next to a bovid chip.

I’m still a bit puzzled about the habitat in which I found these beetles. I would have considered it an anomaly had I not seen two beetles at the same time and then subsequently seen a mating pair in almost the exact same spot. Prairie tiger beetles are known for their preference of open grassland habitats rather than woodlands, and indeed I saw more individuals back along the 2-track that I had abandoned earlier (once I got the courage to stray down it again later in the day). The photo below shows almost the entirety of the opening where I found the beetles, with the bovid chip located on the ground in the lower center of the photo:

An unusually wooded habitat for Cicindelidia obsoleta vulturina.

Seeing these two individuals in the small woodland opening gave me greater optimism that I would be able to find more on the grassy higher slopes above the cedar grove. I crossed the creek and climbed to the top of the first ridge, passing through what seemed to be ideal habitat for the beetle but seeing none. Although igneous in origin, the rocky landscape reminded me very much of the dolomite glades that lace through the White River Hills of southwestern Missouri and that harbour robust populations of this beetle (but occurring nowhere else in the state).

Rocky grasslands extend towards Mt. Scott.

After posting one of these landscape photos on my Facebook page, I got a comment from Thomas Shahan saying he had been to the area recently and seen a “dark Cicindela” atop nearby Elk Mountain. Low and behold, the beetle in the photo that he included was none other than this subspecies, so at least now I know they do occur in this more expected habitat despite my not having seen them on this day.

Failing to find the beetle on higher ground, and wanting to try for even closer photographs, I returned to “the opening” and immediately found another individual to photograph. A female, she may (or may not) have been the partner to the male I photographed earlier, but at any rate she was not nearly as cooperative. I chased her back and forth through the opening for about a half-hour before I finally got close enough to get a shot (my use of tube extensions required that I get even closer than before). As typically happens, however, she gradually became more and more accustomed to my presence, and eventually I was able to get a few photos with the beetle in fairly relaxed, candid poses. The following are my favorites:

A less trusting individual relunctantly allows herself to be photographed.

She looks angry, but in reality I caught her mandibles half open in the midst of chewing movements.

After photographing these individuals, I returned to the car and decided to wander (tentatively) down the 2-track that I had to abandon earlier in the day. This time I fouund the beetles easily, seeing perhaps half a dozen individuals in just the first quarter-mile. My wanderings, however, were once again cut short when I came around a tree bank and saw those same two bison, much closer to the road this time. I really wanted to get a better photograph than the one above, but common sense at first prevented me from getting any closer. I studied the two magnificent behemoths looking for any sign of annoyance, and seeing none I began to creep ever so tiny a bit closer. Eventually my heart rose too high in my throat to approach any closer, and I snapped the following photo and began a hasty, horse-eyed retreat—not even knowing for sure if the shot was good but feeling a little too proud of myself and my stupidity courage!

A little too close for comfort!

Copyright © Ted C. MacRae 2012

9th Annual Fall Tiger Beetle Trip: Day 3.2

/ Ted C. MacRae / 4 Comments

My plan to retrieve beetle-infested wood in Oklahoma’s Glass Mountains has morphed from a quick stop to an all-morning affair, and by the time I loaded up the bundles it was well past noon. Fortunately, my next planned stop—Alabaster Caverns State Park—was only about a 90-minute drive, meaning I would still have plenty of time to give the area a good look. Unlike the Glass Mountains, with its gypsum-capped, flat-topped mesas rising above the surrounding landscape, Alabaster Caverns is level ground fissured by deep, rugged canyons that have eroded through the gypsum cap into the soft, underlying red clay. Nevertheless, both sites are part of the same Gypsum/Red Hills geological formation, so their associated flora and entomofauna are also similar. It was during my original visit to Alabaster Caverns back in 2009 that I found robust populations of Cylindera celeripes (Swift Tiger Beetle), and in October of the following year I discovered its previously unknown larva. My originally intent in coming here this time was to look for Cicindela pulchra (Beautiful Tiger Beetle), but since I had failed to find this species in the Glass Mountains I had little optimism that I would find it here as well. Still, it’s a beautiful park and I was anxious to see some of the canyon areas that I had not explored on previous visits, after which my trip would take a turn to the south.

Alabaster Caverns State Park, Woodward Co., Oklahoma

As I expected, no amount of searching on the flats above showed any evidence of C. pulchra, and I saw pretty much the same assortment of beetles visiting the yellow-flowered Heterotheca stenophylla (stiffleaf false goldenaster) and Gutierezzia sarothrae (broom snakeweed) blooming in profusion that I had seen on Day 2 at Gloss Mountains State Park. Since I had neglected to photograph the gray blister beetle (family Meloidae, genus Epicauta) that I was seeing so commonly the day before, I decided I should go ahead and take advantage of the opportunity while I had it. As I mentioned in my Day 2 post, these beetles were seen almost exclusively on Gutierezzia, and shown below are two of the better photos that I ended up with.

Epicauta sp. | Alabaster Caverns State Park, Woodward Co., Oklahoma

Mouthparts at 3X—love that pollen!

Another species that I saw very commonly were tiny little beetles feeding exclusively on the Heterotheca flowers. Measuring less than 5mm in length, a majority of flowers had at least one of these small gray beetles, and sometimes as many as four or five. Just based on appearance I suspected they represented something in or related to the soft-winged flower beetles (family Melyridae), and in fact they are a dead ringer for the species Listrus senilis(compare to these photos of the MCZ type specimen). This species seems to occur abundantly throughout the Great Plains (Mawdsley 1999) as far south as Texas (BugGuide). The small size of these beetles made them much more difficult to photograph, so my ‘keeper’ rate was lower than for the Epicauta beetle, but a few turned out okay:

Listrus senilis on Heterotheca stenophylla | Alabaster Caverns State Park, Woodward Co., Oklahoma

Listrus senilis at 5X—another pollen lover!

The most significant find of the day, however, was also the most unexpected—I saw numerous individuals of an Acmaeodera jewel beetle feeding on the Heterotheca flowers. Why is this so unexpected? Because throughout most of North America members of the genus Acmaeodera are almost exclusively active as adults during spring and early summer. Those occurring in southeastern Arizona are found more during July and August, a result of the summer monsoon season, but truly fall-active species are limited to a few occurring in the Lower Rio Grande Valley of south Texas. When I saw the first one I presumed it was a late season straggler, but then I saw another, and another. It was clear by their numbers that now is their activity period. I do not know what species they represent, but I took numerous photos and will post them once I have made an identification. It remains to be seen whether this is an unusual habit for a known species (more likely) or a previously unknown species (less likely, though new species of Acmaoeodera continue to be discovered routinely in the U.S.)—stay tuned!

REFERENCE:

Mawdsley, J. R. 1999. Redescription and notes on the biology of Amecocerus senilis (LeConte) (Coleoptera: Melyridae: Dasytinae). Journal of the New York Entomological Society 107(1):68-72.

Copyright © Ted C. MacRae 2012