Fun with eucraniines!

During my February/March 2015 visit to Argentina, I had the opportunity to travel to west-central provinces of San Juan and San Luis with Federico Ocampo for a weekend of insect collecting. Up to that point most of my collecting in Argentina had been limited to the northeastern provinces (Chaco, Corrientes, and Misiones), so I was excited for the chance to explore a radically different biome. West-central Argentina represents a transition zone from the flat, wet, treeless plains of the Humid Pampas in east-central Argentina (Buenos Aires, Santa Fe, and Córdoba Provinces) to the massive Andes Mountains running along the western edge of South America. This area is home to the Monte, a desert biome characterized by volcanic sediments, piedmont plains, large mountain blocks and dry salt lakes. Conditions in the Monte are generally more hospitable than in the neighboring Atacama and Patagonian Deserts lying north and south of the Monte, respectively. As a result, the flora and fauna in the Monte is relatively rich and characterized by a diversity of shrubs, grasses, and cacti.

Dunas de Encón

Encón Dunes, San Luis Province, Argentina

Of the several sites we visited in the area, the most remarkable was “Las Dunas de Encón” (the Encón Sand Dunes) in San Luis Province. Belonging to a larger system covering some 250,000 hectares—the largest in South America (and, thus, sometimes called the “Argentinian Sahara”)—the dunes are thought to have formed some 100–200K years ago as a result of dry conditions brought on by Quaternary glaciations. I find sand dune systems endlessly fascinating due to their unique and often endemic plants and animals and have visited many systems in North America (Bruneau, Coral PinkGlamisGreat, Medora, St. Anthony, and others), but this was the first sand dune system I’ve had the opportunity to see outside of the U.S. Federico, a scarab specialist, shares that fascination and has, in fact, described a number of species in the scarabaeine tribe Eucraniini—endemic to South America—that utilize these very sand dunes (Ocampo 2005, 2007, 2010). He was hoping one or more of them might be out and about; I was hoping to see anything, really.

Host for Lampetis spp.

Parkinsonia praecox? – adult host plant for Lampetis baeri and L. corinthia.

One of the first plants that caught my attention was a woody, fabaceous shrub that looked very much like what I would have previously called Cercidium, now Parkinsonia, and which after a bit of digging I conclude is likely Parkinsonia praecox. Woody, fabaceous shrubs in desert habitats are a sure bet to host jewel beetles, so I began paying special attention to each shrub as I wandered by. It wasn’t long before I saw a large, brilliant metallic green jewel beetle sitting on an outer branch of one of the shrubs—it was one of the most beautiful jewel beetles I have ever seen out in the field with my own eyes! I managed to catch it, and over the next few hours I collected not only several more of this species but also several individuals of an even larger, more somber-colored species. I was able to identify them as Lampetis baeri (Kerremans, 1910) and L. corinthia (Fairmaire, 1864), respectively, when I compared them to material in the collections at Fundacion Miguel Lillo, Instituto de Entomologia, Tucuman, Argentina [IFML]) during my visit there the following week (see photos below).

Lampetis baeri (Kerremans, 1910)

Lampetis baeri (Kerremans, 1910) [IFML]

Lampetis corinthia (Fairmaire, 1864)

Lampetis corinthia (Fairmaire, 1864) [IFML]

As a jewel beetle enthusiast, you would think that was the highlight of my day. In fact, the fun had only started. For a time after our arrival, Federico pointed out burrows likely made by eucraniine adults, but we didn’t see any evidence of activity at first. It wasn’t long, however, before we found the first adult—a fine Eucranium beleni Ocampo, 2010, the largest of the three species occurring at this site (about the size of our North American Deltochilum). One of the more obvious features of eucraniines is their enormously enlarged forelegs and pronotum to hold the musculature required to carry—that’s right, carry!—provisions to the larval burrow (in contrast with the more commonly seen habit among members of the subfamily of using the hind legs to push provisions to the burrow). This unusual morphology gives these beetles not only an amusing, shuffling gait but also a rather comical method for turning themselves upright (as seen in this video narrated by Federico). There are other dung beetles that pull, rather than push, larval provisions (e.g., Sisyphus spp., which stand on highly elongate hind legs and walk backwards while pulling the dungball), but eucraniines seem to be the only ones that actually lift provisions off the ground to carry them. In the case of E. beleni, this involves carrying pieces of dung with the forelegs held out in front of the head while walking forward on the middle and hind legs (Ocampo 2010). I didn’t get to see that behavior with E. beleni, but I did see it with one of another of the eucraniines we found that day (see below). In the E. beleni photo below, note the brushy middle and hind tarsi—an adaptation for walking on loose sand.

Eucranium belenae

Eucranium belenae Ocampo, 2010 walks on its middle/hind legs while holding its forelegs aloft.

Eucranium belenae burrow

Eucranium belenae burrow plugged with a piece of dung.

The second species in the group that we encountered was Anomiopsoides cavifrons (Burmeister, 1861). This species is much smaller than E. beleni (about the size of a large Onthophagus), and unlike E. beleni—and, in fact, most other dung beetles—the larvae of A. cavifrons develop on plant matter rather than dung. Both males and females provision the larval burrows with pieces of plant debris that they pick up with their front legs and carry back to the burrow while walking on their other four legs. This rather amusing video shows a male bringing a piece of debris back to his burrow, then exiting to find and retrieve another piece of debris to bring back to the burrow. The molar region of their mandibles is heavily sclerotized for masticating the plant fibers in preparation for the larvae. There are a couple of other species in the tribe that opportunistically include plant matter in their diet, but A. cavifons seems to be the only one known to utilize dry plant matter in desert habitats almost exclusively (Ocampo 2005). Anomiopsoides cavifrons was far more abundant in the dunes than E. beleni, and by early to mid-afternoon they were encountered with such regularity that I stopped even looking at them.

Anomiopsoides cavifrons male at burrow

Anomiopsoides cavifrons (Burmeister, 1861) male at burrow entrance.

We also were fortunate to see a few individuals of the third species known from these dunes, Anomiopsoides fedemariai Ocampo, 2007. This species is intermediate in size between the extremes represented by E. beleni and A. cavifrons and utilizes pellets of the plains viscacha (Lagostomus maximus), a species of rodent in the family Chinchillidae, for food (Ocampo 2007).

REFERENCE:

Ocampo, F. C. 2005. Revision of the southern South American endemic genus Anomiopsoides Blackwelder, 1944 (Coleoptera: Scarabaeidae: Scarabaeinae: Eucraniini) and description of its food relocation behavior. Journal of Natural History 39(27):2537–2557 [pdf via DigitalCommons].

Ocampo, F. C. 2007. The Argentinean dung beetle genus Anomiopsoides (Scarabaeidae: Scarabaeinae: Eucraniini): description of a new species, and new synonymies for A. heteroclytaRevista Sociedad Entomología Argentina 66(3–4):159–168 [pdf via SciELO Argentina].

Ocampo, F. C. 2010. A revision of the Argentinean endemic genus Eucranium Brullé (Coleoptera: Scarabaeidae: Scarabaeinae) with description of one new species and new synonymies. Journal of Insect Science 10:205, available online: insectscience.org/10.205 [pdf via DigitalCommons].

© Ted C. MacRae 2016

A cicada that snaps, crackles, and pops!

Last summer during a collecting trip through the western Great Plains, field partner Jeff Huether and I made a quick stop in the foothills of the Rocky Mountains just a few miles north of the Colorado/New Mexico state line. Most of the woody vegetation turned out to be New Mexico locust (Robinia neomexicana), which can be a good host for certain species of jewel beetles and longhorned beetles, and since it was mid-late June the timing was also right (assuming there had been good rains in the area). We began beating branches, picking up regular numbers of small longhorned beetles in the genus Sternidius and jewel beetles in the genus Agrilus—nothing unexpected. As I was beating I happened to notice a cicada sitting in a branch in a nearby tree. Usually I don’t see cicadas until they take flight after I unknowingly approach them—more often than not also letting out a metallic screech as they take flight if they are male, and even if I do see them beforehand I rarely am able to get close enough to attempt capture, much less photography. Perhaps the morning temps still had not risen to a point sufficient for the more active behaviors with which cicadas are usually associated.

Platypedia putnami

Platypedia putnami | Las Animas Co., Colorado

The slender, hairy, black body, orange highlights and pronotal collar, and black eyes identify this as a member of the genus Platypedia, and while the genus is large—21 species and four subspecies in western North America (Sanborn & Phillips 2013), its gestalt and occurrence in south-central Colorado make P. putnami the likely choice. Cicadas, of course, are famous for their singing abilities, which is most commonly accomplished through the use of structures at the base of the male abdomen called timbals (or ‘tymbals’). These paired, ribbed membranes make a loud click when buckled, and the male uses musculature to rapidly and rhythmically buckle/unbuckle the timbals to produce their characteristic song (Young & Bennet-Clark 1995). Cicadas of the genus Platypedia, however, belong to a group of genera that have lost the ability to produce sound through timbal organs, instead communicating through an alternate mechanism of sound production called crepitation where the wings are snapped together above the body or banged against the body or on vegetation (Sanborn and Phillips 1999). (Think of the snapping sound that some grasshoppers make as they fly, which is produced by the same mechanism.) You can hear the sound (I can’t really call it a ‘song’) and see a collection of videos of these cicadas at Cicada Mania.

Of course, replacement of one sound production mechanism by another begs the question—is there a selective advantage to sound production by crepitation over timbals? The fact that females also produce sound by crepitation hints at one possible advantage—2-way communication between males and females may provide another mechanism for minimizing the chance of interspecies mate selection, in contrast to the one-way communication (from males to females) that occurs in species that use timbal organs. It is also possible that crepitation is metabolically more efficient than timbal singing, although experimental comparisons of the energetic cost of crepitation versus timbal singing in cicadas are lacking (Sanborn & Phillips 1999).

REFERENCES:

Sanborn, A. F. & P. K. Phillips. 1999. Analysis of acoustic signals produced by the cicada Platypedia putnami variety lutea (Homoptera: Tibicinidae). Annals of the Entomological Society of America 92:451–455 [pdf].

Sanborn, A. F. & P. K. Phillips. 2013. Biogeography of the cicadas (Hemiptera: Cicadidae) of North America, north of Mexico. Diversity 5(2):166–239 [abstractpdf].

Young, D. & H. C. Bennet-Clark. 1995. The role of the tymbal in cicada sound production. The Journal of Experimental Biology 198:1001–1019 [pdf].

© Ted C. MacRae 2015

Why is this male carrion beetle “biting” one of the female’s antennae?

American carrion beetles (Necrophila americana) aggregating at sap flow on the trunk of an oak (Quercus sp.) tree.

American carrion beetles (Necrophila americana) aggregation at sap flow on trunk of oak (Quercus sp.) tree.

Earlier this spring I came upon an interesting aggregation of insects at a sap flow at the base of the trunk of a large oak (Quercus sp.) tree. Sap flows are famous for the diversity of insects that are attracted to them (e.g., see my previous post, Party on a pin oak), although the mix of species present can vary from sap flow to sap flow. In this case, the majority of insects present were American carrion beetles (Necrophila americana)¹ (order Coleoptera, family Silphidae), a species encountered much more often on animal carcasses (in fact, the genus name literally translates to “attracted to corpses“) but also occasionally attracted to sap flows (Evans 2014). This is not surprising to me, as I have seen adults regularly in the fermenting bait traps (Champlain & Knull 1932) that I have set out over the years (although I have been unable to find any reference to such attraction in the literature). I had never seen such an aggregation of these beetles before or even yet had the chance to photograph them (although I have photographed its Ceti Eel-like larva), so I paused to setup the camera and take a few photographs.

¹ Not to be confused with the federally endangered American burying beetle (Nicrophorus americanus).

Necrophila americana mating pair.

Necrophila americana mating pair.

Among the many single adults present was a mating pair, which I selected as my subjects. As I was photographing the pair, I noticed the male had a firm grasp of one of the female’s antennae within his mandibles. As I watched them through the lens, I saw the male suddenly release his hold of the female’s antenna, move backward on top of her, and begin using his own antennae to stroke her pronotum (sadly I was unable to snap a photograph at that time). As suddenly as he had released it, the male moved forward and grabbed hold of the female’s antenna once again. It seemed unlikely to me that this represented an act of aggression, but instead must be an important part of their courtship behavior. The female, for her part, did not seem to be bothered too much by the grasping and continued to slowly lumber about around the sap flow as the male went through his routine under my voyeuristic watch.

The male has a firm grasp of the female's antenna.

The male has a firm grasp of the female’s antenna.

Intrigued by this behavior, I searched for other photos of mating/coupled carrion beetles—easy to do considering the many pages of photographs of this species at BugGuide. While the great majority of those photos are of individual beetles, I found this photo and this one of coupled pairs, each also clearly showing the male firmly grasping one of the female’s antennae with his mandibles. Neither photo makes mention of the antennal grasping, but a little further searching did turn up this YouTube video of coupled American carrion beetles, again clearly showing the male grasping of the female’s antenna and even leading the videographer to comment, “Disturbingly, it even appears that this male is threatening to lop off the female’s left antenna if she refuses to mate!” Of course, retribution seems not to be a common behavior among insects, and in looking into this further I found a short note by Anderson (1989) in which the behavior is recorded not only for N. americana but also another silphid, Oiceoptoma noveboracense. Apparently mating actually occurred during the time the male had released his hold of the female’s antenna and was stroking her pronotum with his antennae. He further noted that the antennal grasping behavior continues until eggs and larvae are present at a carcass, at which time it is no longer observed. This suggests that the behavior represents an especially proactive form of “mate guarding” by which males actively ensure their paternity of the offspring of the particular female with which they were mating.

REFERENCES:

Anderson, R. S. 1989. Potential phylogenetic utility of mating behavior in some carrion beetles (Coleoptera: Silphidae: Silphinae). The Coleopterists Bulletin 43(1):18 [pdf].

Champlain, A. B. & J. N. Knull. 1932. Fermenting bait traps for trapping Elateridae and Cerambycidae (Coleop.). Entomological News 43(10):253–257.

Evans, A. V. 2014. Beetles of Eastern North America. Princeton University Press, Princeton, New Jersey, 560 pp. [Google Books].

© Ted C. MacRae 2015

Multiple Megarhyssa males

Today while hiking at Hilda Young Conservation Area (north-central Jefferson County, Missouri), I encountered a declining sugar maple (Acer saccharum) with lots of woodboring insect holes in the trunk. As I approached I noticed numerous giant ichneumon wasps in the genus Megarhyssa flying about the trunk and resting on its surface. Giant ichneumons belong to the family Ichneumonidae and are, as the name suggests, the largest members of the family in North America. Interestingly, all of the wasps that I initially saw were males. I have never seen male giant ichneumon wasps before, and certainly not in such numbers, so this was quite exciting. We have two species of giant ichneumons here in Missouri—M. atrata and M. macrurus, the females of which I have seen only rarely, but I couldn’t immediately decide which of these two species the males represented. I looked up higher on the trunk, and there I saw a female M. macrurus in the act of oviposition, so I decided that the males must also represent this species. However, one of the males was smaller and differently colored than the others, having more brown than black on the body and the wings clear with a well developed spot on the costal margin. The other males were noticeably larger and had more black than brown on the body and the wings smoky with only a narrow spot on the costal margin. After a little bit of digging, I know believe that the smaller male is also M. macrurus—the same species as the ovipositing female, while the larger males all represent the larger species M. atrata.

Megarhyssa macrurus (male) | Hilda Young Conservation Area, Jefferson Co., Missouri

Megarhyssa macrurus (male) | Hilda Young Conservation Area, Jefferson Co., Missouri

Megarhyssa atrata (male) | Hilda Young Conservation Area, Jefferson Co., Missouri

Megarhyssa atrata (male) | Hilda Young Conservation Area, Jefferson Co., Missouri

As I watched the males that had landed on the trunk of the tree, I observed both the M. macrurus male and one of the M. atrata males to bend their abdomen forward beneath their body rub the tip of the abdomen against the bark, a behavior called “tergal stroking”, and at times inserted the tip of the abdomen into cracks in the bark in an almost prehensile-looking manner. These behaviors belong to a suite of behaviors exhibited by male Megarhyssa aggregations. Previously thought to be function in early insemination of as-yet-unemerged females, the precise function of these behaviors remains unknown but seems somehow related to enabling sex discrimination of emerging wasps and/or increasing the rate at which virgin females are encountered (Matthews et al. 1979).

All species of Megarhyssa parasitize the woodboring larvae of Pigeon horntails (Tremex columba) (order Hymenoptera, family Siricidae), which the females reach by inserting their long, thin ovipositor deep into the wood where the horntail larvae live. Multiple species of giant ichneumons occurring in the same area at the same time and utilizing the same resource seems to violate a basic ecological concept; the competitive exclusion principle, which states that two species competing for the same resource cannot coexist at constant population values because one species will always eventually outcompete the other. In the case of Megarhyssa, it seems that size differences between the species allow them to share a common resource (horntail larvae), as females of the larger M. atrata have longer ovipositors than the smaller M. macrurus, thus allowing them to penetrate deeper into the wood to parasitize horntail larvae that M. macrurus females cannot reach. By the same token, M. macrurus females tend to parasitize horntail larvae tunnel at shallower depths and that tend not to be utilized by M. atrata females.

REFERENCE:

Matthews, R. W., J. R. Matthews & O. Crankshaw. 1979. Aggregation in male parasitic wasps of the genus Megarhyssa: I. Sexual discrimination, tergal stroking behavior, and description of associated anal structures behavior. The Florida Entomologist 62(1):3–8 [pdf].

© Ted C. MacRae 2015

Just how widespread is Prionus heroicus?

On our insect collecting trip to the western Great Plains last June, Jeff Huether and I encountered several species of beetles in the genus Prionus—longhorned beetles (family Cerambycidae) known commonly as “prionid root borers”. I’ve already recounted our experiences with two of them—P. integer in southeastern Colorado and P. fissicornis in northeastern New Mexico, both of which we encountered unexpectedly and by the “bucketload” using prionic acid baited traps in shortgrass prairie habitats. The third species we encountered was also rather unexpected, so much so that we were not even sure about its identity until we examined the collected specimens more closely. Unlike the two previously mentioned species, however, the behavior of this third species—P. heroicus, especially regarding its attraction to prionic acid, was quite different, and one of the localities where we found it raises some interesting questions regarding its recorded distribution.

Prionus heroicus male

Prionus heroicus male | Mills Canyon, Harding Co., New Mexico.

Prionus heroicus is among the largest species in the genus, and we first encountered it in northeastern New Mexico while searching for suitable habitat around the small town of Mills (Harding Co.) where several grassland-associated species in the genus had been found by other collectors. While we were searching we were intrigued by the USDA Forest Service road sign pointing to “Mills Canyon” and decided to head down the gravel road to see what it looked like. A few miles down the road the endless shortgrass prairie quickly changed to sandstone canyonland with oak/pine/juniper woodland. By now it was late afternoon, and the rich, pulsing buzz of cicadas filling the air as we drove slowly through the area suggested the potential for good insect activity. We stopped to take a closer look at things, and within minutes an enormous prionid beetle came flying up to the car—apparently attracted to the prionic acid lures inside!  We netted the beetle, and shortly afterwards another beetle flew into the vicinity… and another! We hurriedly set out some lure-baited traps, and over the next hour or so we collected close to a dozen beetles. Our first thought, based on their large size and the presence of 12 antennal segments, was that they might be P. californicus. This was a bit of a letdown, as our goal was to find little known and uncommonly encountered Great Plains species, not common and widespread western species like P. californicus. However, the blackish rather than reddish color and relatively broad pronotum eventually convinced us that we had actually found P. heroicus—not a rare species, but also not something we expected to see at this relatively northeastern location compared to its usual haunts in southeastern Arizona.

Prionus heroicus male

Males generally landed in the vicinity of the prionic acid lures but seemed unable to locate its precise whereabouts.

Interestingly, none of the beetles came directly to the lure-baited traps but, rather, flew to the vicinity and then either circled broadly in the air or landed some distance from the trap and ran rapidly on the ground as if searching. We missed a few that we tried to net in mid-air, which responded by immediate straight line flight far away into the distance. Those that we watched while on the ground searched for up to several minutes but seemed unable to locate the lure, eventually taking flight and flying away. This suggests that prionic acid is more important as a component of the female’s calling pheromones for long distance detection, but that other components might be necessary to allow the males to locate females in the immediate vicinity. We returned to the site the following day around noon and were surprised to see males flying to our lures immediately after our arrival, since we had observed P. integer and P. fissicornis activity to occur almost exclusively during the morning and evening hours. Linsley et al. (1961), however, also note that adults of this species fly during the day, as well as at night. Again, none of the beetles seemed capable of finding the precise location of the lure.

Prionus heroicus male

Males rapidly searched the ground after landing but seemed unable to locate the lures and eventually flew off.

The larval habits of P. heroicus are not known, but the closely related P. californicus feeds on roots of living oaks or occasionally in dead oak logs or stumps (Linsley 1962). Prionus heroicus may have similar habits, since adult females have been found in leaf litter at the bases of living oak trees and stumps (Hovore & Giesbert 1976, Skiles 1978). Presumably the Mills Canyon population is associated with Gambel oak (Quercus gambelii), which was the only oak species noted at this location. An interesting defensive behavior was observed for an adult beetle that I kept alive and photographed later in the hotel room. I had put the beetle on a light-colored tray, and while I was getting the camera ready to take some shots the beetle began crawling away. I picked it up and put it back into position, and for a brief period it assumed the rather comical-looking “standing-on-its-butt” pose shown in the accompanying photograph. It maintained this pose for some seconds and then gradually lowered itself in the front before beginning to crawl again. If I poked it before it finished lowering itself it immediately pushed its front all the way back up again and held the pose briefly before beginning to lower itself again. I did not encounter this behavior in the field—beetles on the ground immediately tried to flee when I handled them and took flight if allowed to.

Prionus heroicus male

Defensive posturing as a result of being disturbed.

The story does not end here, however, as this would not be our last encounter with the species. While we were traveling back towards the east, we decided to visit the area around Black Mesa in the extreme northwestern corner of the Oklahoma panhandle. I had been to this site the previous summer, and although conditions were very dry at the time the presence of Gambel oak in the area—perhaps the easternmost outpost of this western species—had me thinking about the possibility of the area serving as an unknown eastern outpost for western species of jewel beetles (family Buprestidae). Conditions were once again dry, and no jewel beetles were found, but this quickly became a moot point as not long after our arrival a large prionid beetle came flying up to me—again in the same manner as P. heroicus at Mills Canyon and in the middle of the afternoon. We decided these, too, represented P. heroicus and remained in the area for the rest of the day, counting at least a dozen males attracted to the vicinity of the lures that we’d set out. As with the males we observed in New Mexico, none seemed able to find the precise location of the lure, and some circling only briefly and then flew off without even landing. Unlike New Mexico, however, we did succeed in trapping a few males in lure-bated traps that we set out overnight and checked the next morning.

Prionus heroicus male

This Prionus heroicus male  near Black Mesa, Oklahoma confirms the presence of this species in the state.

Our capture of P. heroicus at Mills Canyon in northeastern New Mexico and near Black Mesa in northwestern Oklahoma not only seems to suggest an association of this species with Gambel oak, but also confirms the previously questionable occurrence of the species in Oklahoma. Alexander (1958) reported the species (under one of its synonyms, P. tetricus) from Payne Co. in north-central Oklahoma. This record is dubious, since Payne Co. is well east of the 100th meridian and has a decidedly eastern flora, including its oaks. That record has not been mentioned by any subsequent authors addressing the overall distribution of P. heroicus (Linsley 1962, Chemsak 1996). The presence of P. heroicus in the Black Mesa area, with its decidedly western flora, does not necessarily give credence to the Payne Co. record, but it does bring up the question of just how broadly distributed P. heroicus really is. Most records of this species are from mountainous areas of southern Arizona and New Mexico, but more recently it has been recorded from Texas (Big Bend National Park) by Van Pelt (1999, 2007) and extreme northwestern Colorado (Moffat Co.) by Heffern (1998). The latter record is particularly interesting, as this represents a considerable range extension from any previously recorded locality and begs the question regarding its occurrence in other parts of Colorado.

REFERENCES:

Alexander, D. R. 1958. A preliminary survey of the cerambycids (Insecta: Coleoptera) of Oklahoma. Proceedings of the Oklahoma Academy of Science 38:43–52 [pdf].

Chemsak, J. A. 1996. Illustrated Revision of the Cerambycidae of North America. Volume I. Subfamilies Parandrinae, Spondylidinae, Aseminae, Prioninae. Wolfsgarden  Books, Burbank, California, x + 149 pp., plates I–X [description].

Heffern, D. J. 1998. Insects of Western North America 1A Survey of the Cerambycidae (Coleoptera) or Longhorn Beetles of Colorado. Gillette Museum of Arthropod Diversity, Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, i + 32 pp., 1 color plate [summary].

Hovore, F. T. & E. F. Giesbert. 1976. Notes on the ecology and distribution of western Cerambycidae (Coleoptera). The Coleopterists Bulletin 30:350 [JSTOR].

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].

Linsely, 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 [pdf].

Skiles, D. D. 1976. Taxonomy and description of two prionine Cerambycidae from southern Arizona: a new species of Stenodontes and new status for Neomallodon arizonicus (Coleoptera). Proceedings of the Entomological Society of Washington 80:407–423 [Biodiversity Heritage Library].

Van Pelt, A. F. (ed.). 1999. Inventory of insects of Big Bend National Park, Texas. Big Bend Natural History Association, Big Bend National Park, and Texas.

Van Pelt, A. F. (ed.). 2007. Inventory of insects of Big Bend National Park, Texas. Report to Big Bend National Park, 204 pp.

© Ted C. MacRae 2015

Best of BitB 2014

Welcome to the 7th Annual “Best of BitB”, where I pick my favorite photographs from the past year. Before I do this, however, let me briefly recap the year 2014. The trend of increasing travel each year continued, with more days spent on the road than in any prior year. Travel for work over the past few years has settled into a familiar routine—touring soybean fields in Argentina in late February and early March, working in my own field trials at (previously three, now four) sites in Illinois and Tennessee from late May through late September, touring more soybean fields at sites across the southeastern U.S. during mid-September, returning to Argentina in October to finalize plans for field trials in the upcoming season, and—finally—attending/presenting at the Entomological Society of America (ESA) Meetings (this year in Portland, Oregon). This heavy travel load makes scheduling my own insect collecting trips a bit tricky, but I’m a persistent sort! In late May I traveled to Tennessee and Georgia with fellow buprestophile Joshua Basham and lab mate Nadeer Youseff to collect several rare jewel beetles, then in late June I collected prionids and jewel beetles in Colorado, New Mexico, and Oklahoma with Jeff Huether. In addition to these longer trips, I also managed to take advantage of my work travel to check out interesting natural habitats along the way to and from my field sites. I continue to give the occasional entomology seminar as well, speaking in March at “Day of Insects” in Ames, Iowa and here in St. Louis to the Entomology Natural History Group of the Webster Groves Nature Study Society in April and the Missouri Master Naturalists Confluence Chapter in December. On top of all this, I still managed to vacation with my family in Lake Tahoe during March and in Cabo San Lucas, Mexico during late July.

I say all this to highlight the fact that after all these years I still consider myself an entomologist with a camera rather than a bona fide insect photographer. The reason for this is that the science of entomology itself remains my primary focus—photography is simply one of the tools that I have come to use in my pursuit of the discipline. I don’t mean to imply that I don’t continue to work on my photography style and technique—because I do. But my style and technique are not goals in of themselves; rather, they are means to an end—that end being my entomological studies. With that said, I present my favorite BitB photographs from 2014. As in previous years, my photos are largely hand-held, in situ field shots that are intended to tell a natural history story in a (hopefully) aesthetic manner. Links to original posts are provided for each photo selection, and I welcome any comments you may have regarding which (if any) is your favorite and why—such feedback will be helpful for me as I continue to hone my craft. If you’re interested, here are my previous years’ picks for 2008, 2009, 2010, 2011, 2012 and 2013. Once again, thank you for your readership, and I hope to see you in 2015!


Paraselenis tersa? female guarding her eggs | Cordoba Prov., Argentina

Paraselenis tersa (Boheman, 1854) | Cordoba Prov., Argentina

From Tortoise beetles on the job (posted April 20). This photograph of a tortoise beetle female over her egg mass illustrates maternal guarding behavior—rare in insects. The perfect lateral profile shot and clean, blue sky background also give the photo a pleasing aesthetic quality.


Who likes mole crickets?

Scapteriscus borellii Giglio-Tos, 1894 | Emanuel Co., Georgia

From Who likes mole crickets? (posted June 6). This has to be the most comical expression ever on the face of an insect!


Chrysobothris orono Frost, 1920 | South Cumberland State Park, Tennessee

Chrysobothris orono Frost, 1920 | South Cumberland State Park, Grundy Co., Tennessee

From Chrysobothris orono in Tennessee (posted July 29). I found this rare jewel beetle for the first time this year with the help of Josh Basham and Nadeer Youseff. The beetle itself is beautiful enough, but photographing it on a pine root with a presumed adult emergence hole adds considerable natural history interest to the photo. Rock substrate behind the root adds a pleasingly blurred background.


Buprestis (Stereosa) salisburyensis Herbst, 1801 | South Cumberland State Park, Tennessee.

Buprestis (Stereosa) salisburyensis Herbst, 1801 | South Cumberland State Park, Tennessee.

From The Buprestis tree (posted August 10). This was another of several jewel beetles that I found for the first time after more than three decades of collecting this group. I like the value contrast in this photo from the striking, metallic colors of the beetle against the nicely blurred cinnamon-colored pine bark of the tree on which it is sitting.


A "super moon" watches over a parasitized hornworm caterpillar.

A “super moon” watches over a parasitized hornworm caterpillar.

From A time of reckoning (posted August 13). I fully admit this is a composite photograph. Nevertheless, it is a faithful recreation of a true sight, and I don’t consider the use of composite techniques to overcome equipment shortcomings to be unethical. There is a haunting symmetry between the blood red moon—considered by some as a sign of the second coming—and the sad, parasitized caterpillar waiting for its inevitable demise.


The greatly expanded palps are thought to mimic beetle mandibles or spider pedipalps.

Phyllopalpus pulchellus Uhler, 1864 | Hickman Co., Kentucky

From My, what busy palps you have! (posted September 2). I’ve become quite fond of insect photos with the subject “peering” at me, the photographer”, from some unusual vantage point. The “pupils” in the eyes of this red-headed bush cricket give the insect an almost quizzical look.


Acmaeodera immaculata Horn, 1881 | vic. Vogel Canyon, Otero Co., Colorado.

Acmaeodera immaculata Horn, 1878 | vic. Vogel Canyon, Otero Co., Colorado.

From Sunset beetles (posted September 30). Taking photos of insects at sunset is a challenging and ephemeral experience—one has only a few minutes to take advantage of the unusual and serene colors it offers, while at the same time trying to determine the best camera and flash settings to use in the rapidly fading light. Of the several that I’ve tried, this one is my favorite because of the softly complimentary colors of the beetle, the flower upon which it is sitting, and the dying orange sky behind it. If I had to choose, I would probably pick this one as my favorite of the year because of the unusual and serene colors.


Megacyllene decora (Olivier, 1795) | Stoddard Co., Missouri

Megacyllene decora (Olivier, 1795) | Stoddard Co., Missouri

From Amorpha borer on goldenrod (posted October 5). I featured this very same species in Best of BitB 2012 but can’t resist choosing this second attempt at photographing the spectacularly beautiful adult—this time on goldenrod. As with the previous version this is a true in situ field photograph, hand held and using the left-hand technique to achieve precise composition against a clear blue sky—difficult to do with an insect of this size and using a 100-mm lens, but well worth the effort.


Buprestis (Knulliobuprestis) confluenta Say, 1823 | Woods Co., Oklahoma

Buprestis (Knulliobuprestis) confluenta Say, 1823 | Woods Co., Oklahoma

From A Buprestis hat-trick! (posted October 14). I didn’t take near as many of the classic “frontal portraits” this year, but this one of a jewel beetle that had eluded me for more than 30 years until this past June is perhaps my favorite of them all.


Agrilus concinnus  Horn, 1891 | Stoddard Co., Missouri

Agrilus concinnus Horn, 1891 | Stoddard Co., Missouri

From North America’s Most Beautiful Agrilus Jewel Beetle (posted October 19). There was a time when this beetle was considered one of North America’s rarest species of jewel beetle. Several years worth of hunting by me and others revealed this beetle’s association with mallow and its unusually late adult activity period—the two combining to make this beetle “seem” rare. This year I succeeded in photographing the spectacular adult beetle.


Cacama valvata female ovipositing

Cacama valvata (Uhler, 1888) | Vogel Canyon, Otero Co., Colorado

From Scorching plains, screaming cactus (posted December 5). Insect photos are always better when they also show some aspect of the subject’s natural history. I was lucky to find this female cactus dodger cicada in the act of ovipositing into the dry stem of cholla cactus—in a position where I could get a perfect lateral profile with a clean, blue sky background.


Moneilema armatum LeConte, 1853 | Vogel Canyon, Otero Co., Colorado

Moneilema armatum LeConte, 1853 | Vogel Canyon, Otero Co., Colorado

From Cactus beetle redux (posted December 20). Cactus beetles can be difficult to photograph, but sometimes they cooperate by nicely posing on a pleasing pink flower bud with a blue sky in the background and the cactus spines forming a nice, fuzzy “halo” around the jet black beetle. There were surprisingly few cactus spines impaled in the control unit of my flash after this photo session.


I hope you’ve enjoyed this 2014 version of “Best of BitB” and look forward to seeing everyone in 2015.

Copyright © Ted C. MacRae 2015

How to catch “bucket loads” of Prionus fissicornis!

Fresh off our unexpected success at finding Prionus integer in the shortgrass prairie of southeastern Colorado, field mate Jeff Huether and I made our way down into northeastern New Mexico to see if the prionic acid lures we used to attract that species would bring us success with other species of Prionus. Several species in this genus are known to occur in the Great Plains, and we had records of three from the area around Gladstone (Union Co.). Based on our experience from the previous day, we stopped at several sites that had sandy/loam soil and searched exposures along the roadsides for burrows that bore any resemblance to those that we had found associated with P. integer. Frustratingly, we saw no such burrows or evidence of the presence of Prionus beetles in any of the spots that we searched.

Eventually, with day’s end drawing near, we decided to play a hunch and set traps at two sites with soil exposures that seemed most similar to those seen the day before. As Jeff set the last pair of traps in place, I occupied myself photographing a dusty hognose snake (Heterodon nasicus gloydi). While photographing the animal, I happened to look down to my side, and what did I see but a male Prionus crawling through the vegetation! I recognized the species immediately as P. fissicornis—represented in my cabinet by a single specimen. This species is distinguished by the highly segmented antennae (up to 30 segments or more) that place it in the monotypic subgenus Prionus (Antennalia). I called out to Jeff, and for the next half an hour or so we scoured the surrounding area; however, our searches were in vain as we failed to find another individual.

Prionus fissicornis male

Prionus (Antennalia) fissicornis male | 24 June 2014, Union Co., New Mexico

We cast an eye towards the north and watched late afternoon thunderstorms roll across the expansive landscape. Rain is normally a downer on an insect collecting trip. However, considering the numbers of P. integer that came to the traps after rain the previous day, we actually found ourselves hoping that the skies would open up. Whether they would and if this would lead to success with P. fissicornis (or other Prionus species), however, would have to wait until the next morning when we returned to check the traps.

Thunderstorms over shortgrass prairie.

Thunderstorms over shortgrass prairie.

Around 10 a.m. the next morning our reward was revealed—traps brimming with P. fissicornis males! Each trap contained more than a dozen individuals, and males were still actively crawling around in the vicinity of the traps as well.

Prionic acid-bated traps w/ Prionus fissicornis males

Prionic acid-bated traps filled w/ Prionus fissicornis males.

Prionic acid-bated traps w/ Prionus fissicornis males

Each trap contained more than a dozen males.

We spent about an hour at the site determining the extent of their occurrence, and like P. integer the previous day the males were found almost exclusively in a small area adjacent to (and upwind from) the traps. As we searched, we also found a few females, one of which seemed to be in the act of ovipositing into the soil at the base of a plant. I carefully excavated the hole into which the ovipositor had been inserted once the female withdrew it, but I was unsuccessful in finding an egg. Perhaps she was only probing to search for a suitable oviposition site and did not find this one to her liking.

Prionus fissicornis female

Prionus (Antennalia) fissicornis female | 24 June 2014, Union Co., New Mexico

There are some interesting similarities and differences with this species compared to our experience with P. integer the previous day. Males of both were highly attracted to the prionic acid lures that we used and were effectively trapped in cans over which the lures were suspended. It is also interesting that both species were found in rather large numbers directly after a rain event, and it seems logical to presume that rain might trigger adult emergence—as is the case with many insects that inhabit dry habitats with seasonal rains. However, we did not find P. fissicornis adults associated with burrows as with P. integer, making me even more intrigued with the burrowing behavior in the latter and its possible function. Also, it is interesting that we found P. fissicornis adults most active during the morning hours and P. integer most active during early evening, but since we did not visit both localities at both times of day it is not possible to say for sure that the two species differ in their adult daily activity.

© Ted C. MacRae 2014

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