Beetle Collecting 101: Fermenting bait traps for collecting longhorned beetles

One of the most useful collecting techniques for those interested in longhorned beetles (families Cerambycidae and Disteniidae) is fermenting bait traps. I was first clued into the use of such traps soon after I began collecting these beetles in the early 1980s and encountered a series of rather old publications by A. B. Champlain and S. W. Frost detailing their usefulness and the diversity of species found to be attracted to them. Champlain & Kirk (1926) listed 15 species of Cerambycidae attracted to bait pans containing a mixture of molasses and water. This list was expanded to 37 species by Champlain & Knull (1932), who noted that a mixture of one part molasses to ten parts water in a gallon-pail seemed to give the best results. Frost & Dietrich (1929) listed 20 species captured with a mixture of one part molasses to 20 parts water. Twelve of the species they mentioned were not listed by Champlain & Knull (1932), and the list of Frost (1937) included two additional previously unrecorded species.

I made extensive use of fermenting bait traps during my 1980s survey of longhorned beetles in Missouri (MacRae 1994) using a mixture of one part molasses, one part beer, nine parts tap water, and a sprinkling of dry active yeast to start fermentation. This recipe was based on that of Champlain & Knull (1932) (although I must confess that I do not remember where I got the idea to add beer and yeast). During that study, I collected 13 species of longhorned beetles using this method and found in other collections specimens of three additional species also collected with fermenting baits. Of the species I collected, the most significant was a large, attractive Purpuricenus that closely resembled P. axillaris (which was also collected in the traps) but clearly was not that species. These eventually proved to be undescribed after I was able to examine type material in the Museum of Comparative Zoology at Harvard University, leading to a review of the genus in North America and the description of the new species as P. paraxillaris (MacRae 2000). Since then I’ve employed fermenting bait traps to collect Cerambycidae in other parts of the country (MacRae & Rice 2007), and I now have records of 72 species of U.S. Cerambycidae documented as being attracted  to fermenting baits.

Molasses-beer fermenting bait trap

Molasses-beer fermenting bait trap.

My interest in this technique was renewed some years ago when I finally succeeded in collecting the spectacular Plinthocoelium suaveolens in fermenting bait traps placed on glades in extreme southwestern Missouri. During my Missouri survey, I had done the bulk of my bait trapping along the edges of glades just south of St. Louis in Jefferson County, and while I had a record of this species in those glades I had never collected it there myself. Finally, last year I observed one of the host trees (gum bumelia, Sideroxylon lanuginosum) on these glades with the characteristic P. suaveolens larval frass pile at the base of the trunk, prompting a renewed effort this past season to collect the species there using fermenting bait traps. In early June I placed a series of traps at Valley View Glades Natural Area (~4 miles NW of Hillsboro) and Victoria Glades Natural Area (~2.5 miles S of Hillsboro). At both locations four traps were placed along the upwind interface between dry, post oak woodland and dolomite glades. Traps were spaced about 50–100 yards apart and hung to ensure exposure to sunlight but minimize the chance they would be discovered by vandals. Each trap consisted of a 2-L plastic bucket with a small hole drilled near the rim on each side and a length of wire attached to allow hanging from a nail in the side of a tree. Two baits were used: 1) molasses/beer, and 2) red wine. The molasses/beer recipe was based on Guarnieri (2009)—more concentrated that what I have used previously, and was prepared by combining a 12-oz (355 mL) jar of dark molasses with an approximately equal volume of tap water in a 1-L plastic bottle, agitating thoroughly, and bringing to one liter volume with tap water. At the trap site, about 500 mL of diluted molasses was added to the trap, followed by a 12-oz can/bottle of beer and one-half of a 7-g packet of dry, active yeast. Red wine bait was a cheap jug variety, undiluted, with about 500 mL added to the trap. Molasses/beer and red wine were alternated in the traps at each location and replaced every two weeks or if excessively diluted by rain or evaporated during hot, dry conditions. Traps were checked weekly from early June to mid-September by pouring the trap contents through a kitchen strainer over an empty bucket and transferring beetles with forceps to empty vials. Once back at the vehicle, tap water was added to each vial and the vial agitated to rinse the specimens and remove bait residue. The water was decanted and the beetles blot-dried with paper towels before transfer to clean vials containing tissue and ethyl acetate to halt decay and maintain the beetles in a relaxed state for pinning.

Cerambycidae from fermenting bait trap

A charismatic trio of Cerambycidae from fermenting bait traps at Victoria Glades: Purpuricenus paraxillaris (left), Plinthocoelium suaveolens (center), and Stenelytrana emarginata (right).

A note about my preferred trap design. I have always used open-top buckets (previously 1-G metal, now 2-L plastic), but “window jugs” (i.e., ½-G milk or juice jugs with holes, or “windows”, cut in the sides) are also commonly used. I have not directly compared buckets with window jugs; however, I favor buckets because I believe beetles attracted to window jugs are more likely to “perch” on the trap itself rather than fall directly into the bait. I also believe that beetles, once trapped, are more likely to escape from window jugs because the window edges provide “grab” sites for beetles before they succumb. The risk of escape can be reduced if the bait surface lies well below the bottom edge of the windows, but this then limits the quantity of bait that can be used. In my experience, 500–750 mL is the minimum volume of bait that is needed to last the duration of the two-week fermentation cycle without evaporating to the point that it is not deep enough to quickly submerge beetles falling into it. Some may be concerned that open-top buckets are prone to dilution by rain, but in my experience this happens infrequently and I have not noticed diluted bait to be any less effective at attracting beetles. Rain shields, on the other hand, only serve to provide a potential perch for beetles attracted to the trap.

Plinthocoelium suaveolens

Plinthocoelium suaveolens captured in flight near its host tree, gum bumelia (Sideroxylon lanuginosum), at Victoria Glades.

A total of 558 longhorned beetles representing 16 species were collected from the traps over the course of the season (see list below). Of these, 339 specimens representing 14 species were attracted to molasses/beer, while 219 specimens representing 14 species were attracted to red wine. Ten species were represented by more than two specimens and were attracted to both bait types, the most desirable being Plinthocoelium suaveolens (41 specimens), Purpuricenus axillaris (20 specimens), P. paraxillaris (3 specimens), and Stenelytrana emarginata (6 specimens). The number of P. suaveolens collected is remarkable, considering that it was not collected during my previous trapping effort spanning several years in the 1980s. It may be significant that 1) the molasses/beer recipe used in this study was considerably more concentrated than that used in the 1980s, and 2) nearly twice as many specimens were collected in red wine (not used in the 1980s) compared to molasses/beer. I routinely examined the gum bumelia trees during my weekly visits in an attempt to find adults on their host, especially during flowering, but encountered only a single adult in flight near one of the trees—a curious result given the diurnal habits and large, conspicuous appearance of the adults. All other species collected in numbers were more attracted to molasses/beer, with the significant exception of Purpuricenus paraxillaris. Seven species taken this season were not detected with fermenting bait traps in the 1980s, bringing to 23 the number of species collected by this method in Missouri. One species, Strangalia sexnotata, is documented from fermenting bait for the first time in this study.

2015 fermenting bait trap catch

2015 fermenting bait trap catch, box 1 of 3 (click to enlarge).

2015 fermenting bait trap catch, box 2 of 3 (click to enlarge).

2015 fermenting bait trap catch, box 2 of 3 (click to enlarge).

2015 fermenting bait trap catch

2015 fermenting bait trap catch, box 3 of 3 (click to enlarge).

Longhorned beetle species and numbers taken in fermenting bait traps in 2015—most to least abundant (MB = molasses/beer, RW = red wine):

  1. Elaphidion mucronatum – 254 (MB = 176, RW = 78)
  2. Eburia quadrigeminata – 145 (MB = 73, RW = 54)
  3. Plinthocoelium suaveolens – 41 (MB = 14, RW = 27)
  4. Neoclytus scutellaris* – 32 (MB = 26, RW = 6)
  5. Parelaphidion aspersum – 26 (MB = 18, RW = 8)
  6. Purpuricenus paraxillaris – 20 (MB = 6, RW = 14)
  7. Orthosoma brunneum – 13 (MB = 8, RW = 5)
  8. Neoclytus mucronatus* – 8 (MB = 6, RW = 2)
  9. Stenelytrana emarginata* – 6 (MB = 5, RW = 1)
  10. Purpuricenus axillaris – 3 (MB = 2, RW = 1)
  11. Enaphalodes atomarius – 2 (MB = 1, RW = 1)
  12. Strangalia famelica solitaria* – 2 (MB = 2, RW = 0)
  13. Typocerus velutinus* – 2 (MB = 1, RW = 1)
  14. Xylotrechus colonus* – 2 (MB = 0, RW = 2)
  15. Elytrimitatrix undatus – 1 (MB = 1, RW = 0)
  16. Strangalia sexnotata** – 1 (MB = 0, RW = 1)

* Not previously reported at fermenting baits in Missouri.
** Not previously reported from fermenting baits anywhere.

With regards to other insects, no attempt was made to quantify their occurrence or diversity, but a few interesting specimens were collected. Elateridae (click beetles) and other beetles were notable by their absence, in contrast to the great diversity recorded from by Champlain & Knull (1932). Flower scarabs were the exception, with two Euphoria inda and a moderate series of E. sepulchralis taken only in red wine traps. The most common non-beetle insects encountered were moths, flies, and stinging wasps, for which molasses/beer seemed to be much more attractive than red wine. The majority of the wasps were Vespidae, but a few large Crabronidae (one Sphecius speciosus and two Stizus brevipennis, I think) and at least two species of Pompiliidae were collected (see box 3 image above).

The diversity of longhorned beetles collected this season was undoubtedly influenced by habitat selection for trap placement (interface between dry, post-oak woodland and dolomite glade). Different habitats would likely yield different species, although prior experience seems to suggest that traps placed in open woodlands are more productive than those placed in dense forests. Recently thinned forests may have good potential due to an abundance of dead wood from thinning operations and trees stressed by sudden exposure to sunlight. Plans are currently underway to place traps (both molasses/beer and red wine) in a variety of wooded habitats during the 2016 season.

REFERENCES:

Champlain, A.B. & H. B. Kirk. 1926. Bait pan insects. Entomological News 37:288–291 [Biodiversity Heritage Library].

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

Frost, S. W. 1937. New records from bait traps. (Dipt., Coleop., Corrodentia). Entomological News 48:201–202 [Biodiversity Heritage Library].

Frost, S. W. & H. Dietrich. 1929. Coleoptera taken from bait-traps. Annals of the Entomological Society of America 22(3):427–436 [abstract].

Guarnieri, F. G. 2009. A survey of longhorned beetles (Coleoptera: Cerambycidae) from Paw Paw, Morgan County, West Virginia. The Maryland Entomologist, 5(1):11–22 [pdf].

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

MacRae, T. C. 2000. Review of the genus Purpuricenus Dejean (Coleoptera: Cerambycidae) in North America. The Pan-Pacific Entomologist 76:137–169 [pdf].

MacRae, T. C. & M. E. Rice. 2007. Distributional and biological observations on North American Cerambycidae (Coleoptera). The Coleopterists Bulletin 61(2):227–263 [pdf].

© Ted C. MacRae 2015

Cactus beetle redux!

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

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

On my most recent Great Plains collecting tripcactus dodger cicadas weren’t the only residents of the cholla cactus (Cylindropuntia imbricata) that studded the open grasslands in southeastern Colorado—cactus beetles (Moneilema spp.) also were found, though in lesser numbers than their frenetic, screeching neighbors (perhaps the reason for their scarcity?!). I’ve covered cactus beetles before, posing the question, “How do you photograph cactus beetles?” The answer was, of course, “Very carefully!” That is certainly true in most cases, but not all.

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

The clumsy, flightless adults rely on their host’s vicious spines for protection.

Cactus beetles are found almost exclusively on opuntioids (chollas and prickly pear cacti), and while most opuntioids are rather viciously spined the plants themselves vary tremendously in structure. Prickly pears (Opuntia spp.), on which I previously photographed these beetles, generally grow in low, dense clumps, their flattened pads often forming a tangle of well-armed hiding places for the beetles. Such is not the case with chollas, which are generally taller, more erect, and have a much more open structure of well spaced, cylindrical stems. The beetles on these plants still enjoy a great amount of protection by the long, barbed spines that cover the stems, but to entomologists/photographers like me they are still much more easily collected and photographed. In this particular case, no special techniques were needed to get nice close-up photos against a clear blue sky other than crouching down a bit and being careful not to lean too close to the plant. That is not to say, of course, that photographing insects on cholla is completely without risk, as this photo showing the spines impaled in my flash unit afterwards will attest (but better the flash unit than poking the lens!).

The hazards of photographing cactus beetles.

The hazards of photographing cactus beetles.

The cactus beetle in these photographs appears to be an armed cactus beetle, Moneilema armatum, by virtue of the small but distinct lateral spines on its pronotum, lack of pubescence on the elytra, and relatively smooth pronotum lacking large punctures except along the apical and basal margins. These shiny black beetles occur in the western Great Plains from Colorado and Kansas south through New Mexico, Oklahoma, and Texas into northern Mexico. Adults and larvae seem to prefer chollas over prickly pears—adults feeding on the surface and larvae tunneling within the stems. I suspect the adult feeding helps provide nutrition for egg maturation in addition to creating an oviposition site, and plants infested with larvae often appear unthrifty and exhibit black masses of hardened exudate along their stems (Woodruff 1966).

Hardened black masses of plant exudate indicate larval feeding within the stems.

Hardened black masses of plant exudate indicate larval feeding within the stems.

REFERENCES:

Linsley, E. G. and J. A. Chemsak. 1984. The Cerambycidae of North America, Part VII, No. 1: Taxonomy and classification of the subfamily Lamiinae, tribes Parmenini through Acanthoderini. University of California Publications in Entomology 102:1–258 [preview].

Woodruff, R. E. 1966. A cactus beetle new to the eastern United States (Coleoptera: Cerambycidae). Florida Department of Agriculture, Division of Plant Industry, Entomology Circular No. 53, 2 pp. [pdf].

© Ted C. MacRae 2014

I got Thomas Shahan to image my Chrysochroa corbetti!

Chrysochroa-corbetti-TwitterThose who follow me on Twitter know that I attended Entomology 2014 last month in Portland, Oregon. As with other scientific conferences, live tweeting of the talks and associated events was all the rage. I may not have been the most prolific “tweeter”, but I did do my share, and one of my tweets involved a rather spectacular preserved specimen of the jewel beetle, Chrysochroa corbetti. The quick iPhone snapshot attached to the tweet was sufficient to prove that the beetle is pure eye candy, but still it did not do full justice to its stunning beauty:

Fortunately, while I was at the meetings I ran into Thomas Shahan—already an icon among insect macrophotographers for his seemingly impossible portraits of jumping spiders, tiger beetles, and other insects. I had planned to spend a couple of days in Salem after the meetings to visit my friend and longtime buprestophile Rick Westcott. As it happens, Thomas is currently a Digital Imaging Specialist at the Oregon Department of Agriculture where Rick spent his entire career as an entomologist. When I showed my specimen to Thomas, he kindly agreed to make some focus-stacked images of the specimen using his lab’s photographic setup. I think you can now agree that this is one of the most spectacular jewel beetles around, and I think you’ll also agree that these images by Thomas are perhaps the most stunning of this oft-photographed species. Be sure to check out the last photo—a 10× close-up of the dorsal elytral detail at the interface between the green and blue areas. Simply stunning!

Chrysochroa (Chroodema) corbetti (Kerremans, 1893) | Thailand

Chrysochroa (Chroodema) corbetti (Kerremans, 1893) | Thailand

Chrysochroa corbetti lateral view

Chrysochroa corbetti lateral view

Chrysochroa corbetti ventral view

Chrysochroa corbetti ventral v

Chrysochroa corbetti dorsal elytral detail (10X)

Chrysochroa corbetti dorsal elytral detail (10X)

© Ted C. MacRae 2014

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

2014 Great Plains Collecting Trip iReport

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

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

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

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

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

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

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

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

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

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

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

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

A "selfie" makes the trip official.

A “selfie” makes the trip official.

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

Shortgrass prairie habitat for Prionus integer.

Shortgrass prairie habitat for Prionus integer.

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

Prionus integer male | Bent Co., Colorado

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

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

Prionus integer adult burrow.

Prionus integer adult burrow.

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

Prionus integer mating pair.

Prionus integer mating pair.

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

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

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

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

Thunderstorms over shortgrass prairie.

Thunderstorms over shortgrass prairie.

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

Sunset over shortgrass prairie.

Sunset over shortgrass prairie.

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

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

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

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

Prionic acid-bated traps w/ Prionus fissicornis males.

Prionic acid-bated traps w/ Prionus fissicornis males.

Prionic acid-bated traps w/ Prionus fissicornis males.

Prionic acid-bated traps w/ Prionus fissicornis males.

Prionus fissicornis male | Harding Co., New Mexico.

Prionus fissicornis male | Harding Co., New Mexico.

Prionus fissicornis oviposition hole.

Prionus fissicornis oviposition hole.

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

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

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

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

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

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

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

Who's home?

Who’s home?

Peek-a-boo!

Peek-a-boo!

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

Cylindropuntia imbricata | Otero Co., Colorado.

Cylindropuntia imbricata | Otero Co., Colorado.

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

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

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

The hazards of photographing cactus beetles.

The hazards of photographing cactus beetles.

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

Lithographs on canyon wall | Mills Canyon, Colorado.

Lithographs on canyon wall | Mills Canyon, Colorado.

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

The author looks pensively out over the Black Mesa landscape.

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

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

Prionus heroicus male

Prionus heroicus male

Bite from Prionus heroicus male.

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

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

Dove's nest w/ eggs.

Dove’s nest w/ eggs.

Dinosaur fossil footprint

Freshly quarried dinosaur fossil footprint

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

Longhorn skull on barn at our Bead and Breakfast.

Longhorn skull on barn at our Bead and Breakfast.

132-year-old stagecoach - model!

132-year-old stagecoach – model!

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

Dinosaur tracks | vic. Black Mesa, Oklahoma.

Dinosaur tracks | vic. Black Mesa, Oklahoma.

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

Dinosaur tracks | vic. Black Mesa, Oklahoma.

Dinosaur tracks | vic. Black Mesa, Oklahoma.

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

Wood collected for rearing wood-boring beetles.

Wood collected for rearing wood-boring beetles.

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

© Ted C. MacRae 2014

Sunset beetles

Acmaeodera immaculata? | vic. Vogel Canyon, Colorado.

Acmaeodera immaculata? (family Buprestidae) | vic. Vogel Canyon, Colorado.

Regular readers of this blog know that I am fond of natural sky backgrounds for insects found during the day on flowers and foliage. Not only does the sky provide a clean, uncluttered background that allows the subject to stand out, it also gives the photo a more appropriate temporal flavor—i.e., photographs of diurnal insects should look like they were taken during the day. It’s a little bit tricky setting the camera to allow flash illumination of the subject while still allowing the sky to register as well, but I find such photographs more pleasing and interesting than those with a jet-black background, typical in flash macrophotography, and far more pleasing than those with a jumble of sticks and weeds cluttered behind the subject. These days my daytime insect photos almost always incorporate a blue-sky background (examples here and here) unless: 1) I actually photographed the subject at night (examples here and here); or 2) I wish to highlight an intensely white or delicately structured subject (examples here and here).

Aulicus sp. | vic. Black Mesa, Oklahoma

Trichodes oresterus? (family Cleridae) | vic. Black Mesa, Oklahoma

But what about in between day and night—specifically, sunset? Incorporating a sunset sky into a flash-illuminated macrophotograph is even trickier than incorporating a blue midday sky because the central problem—low light levels—is magnified. Blue sky photographs challenge the fast shutter speeds and high f-stops usually needed for macrophotographs, but relatively minor adjustments to ISO, shutter speed, and f-stop are usually sufficient to allow the sky to register while still being able to maintain depth of field and minimize motion blur. At sunset, however, because there is much less illumination of the sky, more aggressive settings are often required to allow the sky to register on the camera sensor—settings that can sometimes result in too much motion blur or insufficient depth of field. These problems can be mitigated to some degree with the use of a tripod (and very cooperative subjects), but for dedicated “hand-held” enthusiasts like myself this is not an option. Why bother? Because the results can be spectacular! The setting sun often creates stunning colors not seen at other times of the day and offer a change of pace from blue skies, which, like black backgrounds, can start looking rather monotonous if used exclusively in one’s portfolio.

Linsleya convexa | vic. Vogel Canyon, Colorado

Linsleya convexa (family Meloidae) | vic. Vogel Canyon, Colorado

The photos featured in this post were taken during several sunsets on a trip earlier this past summer through Colorado and Oklahoma. I especially like the jewel beetle (Acmaeodera immaculata?) photograph—technically it has good focus and depth of field and a pleasing composition, but I really like the color coordination between the beetle, flower, and sky. The checkered beetle (Trichodes oresterus?) photograph is also very pleasing, especially the detail on the beetle, although the color of the sky is only somewhat different than a more typical daytime blue. The blister beetle (Linsleya convexa) photograph is probably the most problematic technically due to slight motion blur and being slightly off-focus at the eye—not surprising since of the three this photo had the lowest light conditions. However, the color contrast between the sky and subject make this a nevertheless striking image.

If you have experience with ambient light backgrounds in flash macrophotography, your comments on approaches you’ve taken to deal with reduced light situations will be most welcome.

© Ted C. MacRae 2014

Southern armyworm feeding on soybean

Southern armyworm (Spodoptera eridania) late-instar larva feeding on soybean.

Southern armyworm (Spodoptera eridania) late-instar larva feeding on soybean.

Here is another animated gif that I made recently, this one showing a late-instar larva of southern armyworm (Spodoptera eridania) feeding on soybean (Glycine max). This polyphagous species is widely distributed from the southern U.S. through the northern half of South America and feeds on a variety of weeds, especially pigweed (Amaranthus spp.) and pokeweed (Phytolacca americana). It also occasionally attacks vegetable, fruit, and ornamental crops; however, in recent years it has become increasingly important on cultivated soybean in Brazil and Argentina, especially in regions where cotton is also cultivated. As a result, they have become one of the insects that I deal with regularly in my own research. More information on this and other armyworm species that affect soybean can be found in my earlier post, Quick Guide to Armyworms on Soybean.

Like many other lepidopteran caterpillars that feed on foliage, late-instar larvae become “feeding machines” that remain active both day and night as they try to cram as much nutrition into their expanding bag of a body as possible in preparation for an adult life focused solely on finding mates and laying eggs. Large larvae actively feeding during the day can be rather conspicuous, and as a result they often secrete themselves on the undersides of the leaves while feeding to make themselves less visible to predators. As they feed, however, a “window” opens up that gradually eliminates their cover. Rather than remaining in the same spot and feeding until they are completely exposed, however, larvae will move when the feeding hole reaches a certain size and find another place to conceal themselves before resuming feeding. Different caterpillar species have different exposure tolerances, and as a result, this combines with slight differences also in preferred tissue types to create recognizable differences in the damage patterns resulting from feeding by different species.

For those interested, making these animated gifs is really simple and allows those of us without expensive macro-video gear to simulate short videos of insect behavior. I make my animated gifs at GIFMaker.me—all you do is take a series of photos, touch them up in photo editing software (I use Photoshop Elements to adjust levels, color and sharpness), upload them to the site in the sequence desired, and click “Create Now”. It couldn’t be easier! You don’t even need a “real” camera—I took the photos for this gif with my iPhone using the “burst” function to take a rapid sequence of photos (all you do is hold your finger down on the shutter button for the desired length of time).

© Ted C. MacRae