Tortoise beetles on the job

Back in late February and early March I did my annual tour through the soybean growing regions of central and northern Argentina to look at insect efficacy trials (pretty amazing to me still when I think about it—I actually get paid to spend time in Argentina looking for insects!). Normally on such trips there is no shortage of soybean insects to occupy my attentions—of all the large-acre row crops, soybean probably has the greatest diversity of insect associates, and in South America it is rare for any soybean field to not experience pressure from at least one of them. Soybeans, however, are not the only plants that occur in soybean fields—there are also weeds, many of which also have their own suite of insect associates. Sometimes these weed-associated insects can be even more interesting than the soybean insects I’m look for.

Botanochara angulata?

Botanochara angulata? mating pair | Córdoba Prov., Argentina

On this particular day, as I walked through a soybean field in central Córdoba Province I noticed distinctive red and black tortoise beetles (family Chrysomelidae, subfamily Cassidinae) on some of the plants. I thought it odd that tortoise beetles would be on soybean, as I’m not aware of any soybean associates in the group. A closer look, however, quickly revealed that the beetles were not on the soybean plants themselves, but rather on vines that were weaving their way through the plants. The plant was akin to bindweed and obviously a member of the same plant family (Convolvulaceae), but none of my field mates knew which of the many weedy species of the family that occur in Argentina that this particular plant represented. Species of Convolvulaceae are, of course, fed upon by a great diversity of tortoise beetles—always a treat for this coleopterist to see, and it was all I could do to concentrate on the task at hand and finish doing what I needed to do so I could turn my attention to finding and photographing some of these beetles. Once I began photographing them I found them surprisingly uncooperative (not my normal experience with tortoise beetles), but I soon found a mating pair that was a little more cooperative (probably because they were mating), with the above photo being my favorite of the bunch.

Paraselenis tersa?

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

As I was searching for beetles to photograph, I encountered some yellow tortoise beetles associated with the same plant but that I had not noticed earlier. Unlike the conspicuously red and black colored species (which seems to best match Botanochara angulata according to Cassidinae of the World), the yellow species (which I presume represents Paraselenis tersa, also ID’d using the same site) seemed almost cryptically colored. When I finished taking photographs of B. angulata, I began searching for a P. tersa to photograph and encountered the female in the above photograph guarding her eggs—score!

Undetermined cassidine larvae.

A single tortoise beetle larva was encountered.

Tortoise beetle larvae are always a delight to see as well—their dinosaurian armature and fecal adornments, both obviously designed to dissuade potential predators, form one of the most ironic defensive combinations one can find. If additional tactics become necessary, they are among the few insects that are known to actually “circle the wagons” (the technical term for this being “cycloalexy“). While I only found a single larvae (of which species I don’t know), its presence seems to further suggest that at least one of the species represented an actively developing population and that the adults I found were not just hangers-on putzing around until winter (such as it is in central Argentina) forced them to shut down for the season.

Undetermined cassidine larva.

Spiky spines and a pile of poop make formidable defenses.

My impression is that tortoise beetles are by-and-large noxious to predators, thus explaining why so many species in the group exhibit aposematic coloration. However, the apparent cryptic coloration of Paraselenis makes me wonder if this is not universally true. It seems especially odd for two species to feed on the exact same species of plant but only one of the species to be noxious, which leads me to even more questions about how two species feeding on the same plant at the same time avoid direct competition with each other. I wondered if perhaps one species was on the wax while the other was on the wane (late February is well along into the latter part of the season in central Argentina), but the fact that both species were involved in reproductive activities (mating in Botanochara and egg guarding in Paraselenis) suggests this was not the case.

Ted MacRae photographing tortoise beetles.

A candid photo of me photographing tortoise beetles (and revealing my technique for getting “blue sky” background photographs).

© Ted C. MacRae 2014

Posted in Chrysomelidae, Coleoptera | Tagged , , , , , , , , | 6 Comments

A Crossidius hirtipes subspecies blend zone…

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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


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

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

Copyright © Ted C. MacRae 2014

Posted in Cerambycidae, Coleoptera | Tagged , , , , , , , , , | Leave a comment

Introducing Acmaeodera chuckbellamyi

Acmaeodera chuckbellamyi MacRae, 2014 | Atascosa Mountains, Arizona

Acmaeodera chuckbellamyi MacRae, 2014 | Holotype female (scale bar = 1 mm) (MacRae 2014: Fig. 1).

Of the many entomology journals I subscribe to, there are few that I await with as much anticipation as The Coleopterists Bulletin. Focusing exclusively on the largest order of life on earth, it’s a quarterly dose of elytral ecstasy that no beetle enthusiast should be without. I awaited the March 2014 issue, however, with special anticipation, as this was the issue that would honor my late friend and colleague, Chuck Bellamy. Last week, the issue arrived in my mailbox, and it did not disappoint!

The issue begins with an In Memorium, spearheaded by fellow buprestophile Rick Westcott and containing contributions and photos from many of Chuck’s contemporaries (including me) (Westcott et al. 2014). This is followed by an especially touching remembrance of Chuck by his longtime friend Art Evans (with whom Chuck co-authored An Inordinate Fondness for Beetles), after which come 11 scientific papers with descriptions of new beetle taxa named in Chuck’s honor. These include nine new species of jewel beetles (family Buprestidae) from Mexico, Central America, China, Kenya, Europe, Peru, and Arizona, a new seed beetle (family Bruchidae) from Mexico, and two new checkered beetles (family Cleridae) from Mexico. For my part, I described one of the jewel beetles, a member of the genus Acmaeodera known from but a single specimen¹ collected in southeastern Arizona which I dedicated to Chuck with the name “Acmaeodera chuckbellamyi MacRae, 2014″. Last but not least, the Fall family provides some remembrances of Chuck and his association with BioQuip Products, Inc.

¹ It is generally not advisable to describe a new species based on a single specimen. However, in this case multiple attempts to recollect the species were unsuccessful, and eventually the type locality was significantly altered in 2009 by the Murphy Fire. It is possible (and indeed likely) that the species still exists in similar nearby habitats (especially further south in Mexico), but the circumstances mentioned above make it unlikely that additional material will become available for the foreseeable future. In such cases, it is, in my opinion, better to name the species so that it can be made available to the broader scientific community.

In all, 12 new beetle taxa are named in Chuck’s honor, bringing the total number of patronyms honoring him to six genus-group names and 31 species-group names—a fitting legacy and testament to the breadth of his impact in the taxonomic community. The issue can be found online at BioOne—abstracts are freely available, but membership in The Coleopterists Society is required to access full-text and pdfs. For those who are not society members, I offer below pdf versions of the two papers that I authored or co-authored.


Westcott, R. L., S. Bílý, A. R. Cline, S. D. Gaimari, H. Hespenheide, T. C. MacRae, M. G. Volkovitsh, S. G. Wellso & G. Williams. 2014. In Memoriam: Charles Lawrence Bellamy (1951–2013). The Coleopterists Bulletin 68(1):1–13 [pdf].

MacRae, T. C. 2014. Acmaeodera chuckbellamyi MacRae (Coleoptera: Buprestidae: Acmaeoderini), a new species from Arizona, USA. The Coleopterists Bulletin 68(1):50–52 [pdf].

© Ted C. MacRae 2014

Posted in Buprestidae, Coleoptera | Tagged , , , , , , , , | 7 Comments

Tiger beetles in Argentina’s Chaco forest

The day after I photographed Brasiella argentata on the mud/san banks of the Rio Paraná in Corrientes, Argentina, I decided to drive westward into the heart of Chaco Province. The destination: Chaco National Park, where some of the best remaining examples of the original “Gran Chaco” remain. Once covering nearly a million square kilometers in northern Argentina, Paraguay and Bolivia, this distinctive ecoregion has been largely converted to a vast, hot sea of cotton fields and mesquite fence-rows. A unique plant community in the Gran Chaco is the quebracho forest that takes its name from quebracho colorado chaqueño (Schinopsis balansae)—a tall, massively-trunked tree (related to, of all things, poison ivy!) with beautiful red wood that has been logged relentlessly wherever it occurs. Chaco National Forest is unique for the largely intact example of this forest it preserves and the mature quebracho trees that it contains.

Odontocheila chrysis | Chaco National Park, Argentina

Odontocheila chrysis (Fabricius, 1801) | Chaco National Park, Argentina

Insect life was not abundant as I walked the dark forest path. The lateness of the season (early April) and long-enduring drought occurring in the region had taken their toll, and I was content to see just about anything. At one point, a flash of movement caught my eye, and as I scanned the forest floor in the area where I had seen it, the familiar silhouette of a Golden Forest Tiger Beetle—Odontocheila chrysis (Fabricius, 1801)—became visible. I was already familiar with this species, having seen fairly good numbers of them at another location further east during my first visit to the area 12 years earlier. Long-legged and fast-flying, this tiger beetle occurs throughout much of South America, where it lives in more shaded areas of forest clear-cuts, secondary forests, savannas, and open scrublands (Erwin & Pearson 2008). The ground-dwelling adults are known to congregate along paths and at large openings on the forest floor, and indeed I had seen them in their greatest numbers on a shaded dirt road around the margins of a temporary mud puddle. When disturbed, the wary adults fly up from the forest floor to land in adjacent bare area of substrate or on the leaves of understory plants.

Superposition eyes are adapted to the dark forest environment in which this species lives.

Superposition eyes are an adaptation to the dark forest environment where this species lives.

I faced a bit of a quandary when I saw this individual—do I collect it as a voucher and studio photograph backup, or do I go ahead and try to get the much more desirable in situ photograph of an unconfined adult in its native habitat. Considering that I had already collected a sufficient number during my earlier trip, I opted for the latter. I am fortunate that I got these two quite acceptable photographs before the adult flashed away in the blink of an eye right after I took the second shot, because I never saw another one the rest of the day or even the trip.  

An interesting feature of O. chrysis is its superposition eyes. In such eyes, each rhabdom (light sensitive unit) in the compound eye receives light through many ommatidial facets. This is in contrast to apposition compound eyes, where each rhabdom receives light from only a single facet. Superposition eyes are designed to increase photon capture, which is an advantage in the dark forest habitats where this beetle prefers to live (Brännström 1999).

Brasiella argentata | Chaco National Park, Argentina

Brasiella argentata (Fabricius, 1801) | Chaco National Park, Argentina

Shortly after photographing O. chrysis, I came upon a small opening where the path was a little wider and sunnier and the soil a little sandier and drier. Immediately I saw the small, zippy flits of the same tiger beetle species I had photographed the previous day on the banks of the Rio Paraná—Brasiella argentata. I could not find in the literature whether this species has superposition or apposition compound eyes, but considering that the species occur in great numbers on sunny river banks and that the few individuals I saw in the forest were in a sunny opening, I’m betting it’s the latter.

I couldn’t help but make another attempt to photograph this species, considering the difficulty I’d had the previous day (and that I wasn’t completely satisfied with any of the photos that I had obtained). More good fortune, despite there being only a few individuals to work with, as I managed to get the above photograph, which I consider far better than any that I already had. These beetles, too, quickly disappeared, and I never saw them again, but knowing I had the photos that I wanted made that okay.

Habitat for Odontocheila chrysis and Brasiella argentata

Quebracho forest habitat for Odontocheila chrysis and Brasiella argentata.


Brännström, P. A. 1999. Visual ecology of insect superposition eyes. Unpublished Ph.D. Dissertation, Lund University, 142 pp. [abstract].

Erwin, T. L. & D. L. Pearson. 2008. A Treatise on the Western Hemisphere Caraboidea (Coleoptera). Their classification, distributions, and ways of life. Volume II (Carabidae-Nebriiformes 2-Cicindelitae). Pensoft Series Faunistica 84. Pensoft Publishers, Sofia, 400 pp. [Amazon descriptionbook review].

© Ted C. MacRae 2014

Posted in Cicindelidae, Coleoptera | Tagged , , , , , , | 6 Comments

ID Challenge #22

For this ID Challenge, please identify the objects/structure in the photos below and discuss how they are related to each other. I’ll give 5 pts to anybody who correctly identifies the object/structure in each photo and another 5 pts to anyone who correctly elucidates their connection. Go!

Edit: I am looking for a family-level ID for the objects in the first photo and a genus-level ID for the plant bearing the structure in the second photo to get full credit. Answers will be held in moderation until the answers are revealed to give all a chance to play.

What are these?

What are these objects?

What is this, and how does it relate to the structures in the other photo?

What is this structure, and how does it relate to the objects in the first photo?

© Ted C. MacRae 2014

Posted in [No taxon] | Tagged , | 16 Comments

Crossidius hirtipes rhodopus in Adobe Valley, California

Crossidius hirtipes rhodopus | Adobe Valley, Mono Co., California

Crossidius hirtipes rhodopus Linsley, 1955 | Adobe Valley, Mono Co., California

On Day 7 of last August’s Great Basin Collecting Trip, we left Bishop and headed back north to the Mono Basin to look for Crossidius hirtipes rhodopus, a distinctive reddish subspecies known only from the Mono Basin. I’d seen this beetle before—almost 20 years ago during one of several trips to the type locality of Nanularia monoensis (described by my late friend Chuck Bellamy in his 1987 revision of the genus), so we drove south of Mono Lake on Hwy 120 through Adobe Valley on our way to the Benton Range where I last saw them. Of course, C. h. rhodopus occurs more broadly in the Mono Basin than just the Benton Range, and as we drove through the valley we saw robust stands of the beetle’s host plant, yellow rabbitbrush (Chrysothamnus viscidiflorus), in full bloom stretching across the floor of the valley to the towering White Mountains in the distance. Impatience can sometimes be a virtue, and in this case our decision to stop and check the plants rather than waiting until we got to the Benton Range paid off—not only were the beetles out in force, allowing us to photograph and collect to our heart’s content, but we saw only a few beetles on but a single flowering plant during our subsequent visit to the Benton Range. Apparently the rains that had caused such a profusion of bloom in the Adobe Valley had not graced the Benton Range, resulting in the driest conditions I have seen during my several visits there.

This subspecies is one of the more darkly colored subspecies

This subspecies is one of the more darkly colored subspecies

Crossidius h. rhodopus is among the most distinctive of all the C. hirtipes subspecies due to its dark reddish-brown coloration. It closely resembles C. h. nubilus, which we had seen the day before at its only known locality further south at Westgaard Pass between the White and Inyo Mountains, but it is not as dark as that subspecies and lacks the extensive clouding of black on the apical portions of the elytra. The red-brown legs and brown antennae becoming darker at the tip further characterize C. h. rhodopus, originally described as a full species (Linsley 1955) but later regarded as a subspecies of the widely distributed and highly polytopic C. hirtipes LeConte, 1854 (Linsley & Chemsak 1961).

Yellow rabbitbrush (Chrysothamnus viscidiflorus) abounds in the valley, as the White Mountains loom in the background.

Yellow rabbitbrush (Chrysothamnus viscidiflorus) abounds below the magnificent White Mountains.

Those who are unfamiliar with the Mono Basin are missing one of California’s greatest natural treasures. A closed, internal-drainage basin bordered to the west by the massive Sierra Nevada Mountains (with Yosemite National Park lying just over the peaks), to the east by the Cowtrack Mountain, to the north by the Bodie Hills, and to the South by the north ridge of the Long Valley, the eerily beautiful Mono Lake is its most prominent feature. Do not, however, neglect other areas of the basin, which offer their own uniquely dramatic beauty. Adobe Valley, stretching south of the lake towards the White Mountains and famous for the wild mustang that live there, is one such area.

A handsome male rests on yellow rabbitbrush flowers (studio shot).

A robustly handsome female perches a terminal flower cluster of yellow rabbitbrush (studio shot).


Linsley, E. G. 1955. Notes and descriptions of some species of Crossidius. The Pan-Pacific Entomologist 31(2):63–66.

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

© Ted C. MacRae 2014

Posted in Cerambycidae, Coleoptera | Tagged , , , , , , , , , | 6 Comments

Beetle Collecting 101: How to rear wood-boring beetles

I’ve been collecting wood-boring beetles for more than three decades now, and if I had to make a list of “essential” methods for collecting them I would include “beating,” “blacklighting,” and “rearing.” Beating is relatively straightforward—take a beating sheet (a square piece of cloth measuring 3–5 ft across and suspended beneath wooden, metal, or plastic cross members), position it beneath a branch of a suspected host plant, and tap the branch with a stick or net handle. Many wood-boring beetles tend to hang out on branches of their host plants, especially recently dead ones, and will fall onto the sheet when the branch is tapped. Be quick—some species (especially jewel beetles in the genus Chrysobothris) can zip away in a flash before you have a chance to grab them (especially in the heat of the day). Others (e.g., some Cerambycidae) may remain motionless and are cryptically colored enough to avoid detection among the pieces of bark and debris that also fall onto the sheet with them. Nevertheless, persistence is the key, and with a little practice one can become quite expert at efficiently collecting wood-boring beetles using this method. Blacklighting is even easier—find the right habitat (preferably on a warm, humid, moonless night), set up a blacklight in front of a white sheet, crack open a brew, and wait for the beetles to come!

Rearing, on the other hand, takes true dedication. One must not only learn potential host plants, but also how to recognize wood with the greatest potential for harboring larvae, retrieve it from the field, cut it up, place it in rearing containers, and monitor the containers for up to several months or even years before hitting pay dirt (maybe!). Despite the considerable amount of effort this can take, the results are well worth it in terms of obtaining a diversity of species (usually in good series), some of which may be difficult to encounter in the field, and identifying unequivocal larval host associations. I have even discovered two new species through rearing (Bellamy 2002, MacRae 2003)! Moreover, checking rearing containers can be a lot of fun—in one afternoon you can collect dozens or even hundreds of specimens from places far and wide, depending on how far you are willing to travel to collect the wood. Because of the effort involved, however, the more you can do to ensure that effort isn’t wasted on uninfested wood and that suitable conditions are provided to encourage continued larval development and adult emergence from infested wood the better. It is with this in mind that I offer these tips for those who might be interested in using rearing as a technique for collecting these beetles.

I should first clarify what I mean by “wood-boring” beetles. In the broadest sense this can include beetles from any number of families in which the larvae are “xylophagous,” i.e., they feed within dead wood. However, I am most interested in jewel beetles (family Buprestidae) and longhorned beetles (family Cerambycidae), and as a result most of the advice that I offer below is tailored to species in these two families. That is not to say that I’ll turn down any checkered beetles (Cleridae), powderpost beetles (Bostrichidae), bark beetles (family Scolytidae), or even flat bark beetles sensu lato (Cucujoidea) that I also happen to encounter in my rearing containers, with the first two groups in particular having appeared in quite good numbers and diversity in my containers over the years. Nevertheless, I can’t claim that my methods have been optimized specifically for collecting species in these other families.

First, you have to find the wood. In my experience, the best time to collect wood for rearing is late winter through early spring. A majority of species across much of North America tend to emerge as adults during mid- to late spring, and collecting wood just before anticipated adult emergence allows the beetles to experience natural thermoperiods and moisture regimes for nearly the duration of their larval and pupal development periods. Evidence of larval infestation is also easier to spot once they’ve had time to develop. That said, there is no “bad” time to collect wood, and almost every time I go into the field I am on the lookout for infested wood regardless of the time of year. The tricky part is knowing where to put your efforts—not all species of trees are equally likely to host wood-boring beetles. In general, oaks (Quercus), hickories (Carya), and hackberries (Celtis) in the eastern U.S. host a good diversity of species, while trees such as maples (Acer), elms (Ulmus), locust (Gleditsia and Robinia), and others host a more limited but still interesting fauna. In the southwestern U.S. mesquite (Prosopis) and acacia (Acacia) are highly favored host plants, while in the mountains oaks are again favored. Everywhere, conifers (PinusAbies, JuniperusTsuga, etc.) harbor a tremendous diversity of wood-boring beetles. To become good at rearing wood-boring beetles, you have to become a good botanist and learn not only how to identify trees, but dead wood from them based on characters other than their leaves! Study one of the many good references available (e.g., Lingafelter 2007, Nelson et al. 2008) to see what the range of preferred host plants are and then start looking.

I wish it were as simple as finding the desired types of trees and picking up whatever dead wood you can findm but it’s not. You still need to determine whether the wood is actually infested. Any habitat supporting populations of wood-boring beetles is likely to have a lot of dead wood. However, most of the wood you find will not have any beetles in it because it is already “too old.” This is especially true in the desert southwest, where dead wood can persist for very long periods of time due to low moisture availability. Wood-boring beetles begin their lives as eggs laid on the bark of freshly killed or declining wood and spend much of their lives as small larvae that are difficult to detect and leave no obvious outward signs of their presence within or under the bark. By the time external signs of infestation (e.g., exit holes, sloughed bark exposing larval galleries, etc.) become obvious it is often too late—everything has already emerged. Instead, look for branches that are freshly dead that show few or no outward signs of infestation. You can slice into the bark with a knife to look for evidence of larval tunnels—in general those of longhorned beetles will be clean, while those of jewel beetles will be filled with fine sawdust-like frass that the larva packs behind it as it tunnels through the wood. Oftentimes the tunnels and larvae will be just under the bark, but in other cases they may be deeper in the wood. Broken branches hanging from live trees or old, declining trees exhibiting branch dieback seem to be especially attractive to wood-boring beetles, while dead branches laying on the ground underneath a tree are not always productive (unless they have been recently cut).

One way to target specific beetles species is to selectively cut targeted plant species during late winter, allow the cut branches to remain in situ for a full season, and then retrieve them the following winter or early spring. These almost always produce well. Doing this will also give you a chance to learn how to recognize young, infested wood at a time that is perfect for retrieval, which you can then use in searching for wood from other tree species in the area that you may not have had a chance to cut. I have cut and collected branches ranging from small twigs only ¼” diameter to tree trunks 16″ in diameter. Different species prefer different sizes and parts of the plant, but in general I’ve had the best luck with branches measuring 1–3″ diameter.

Once you retrieve the wood, you will need to cut it into lengths that fit into the container of your choice (a small chain saw makes this much easier and quicker). In the field I bundle the wood with twine and use pink flagging tape to record the locality/date identification code using a permanent marker. I then stack the bundles in my vehicle for transport back home. Choice of container is important, because moisture management is the biggest obstacle to rearing from dead wood—too much moisture results in mold, while too little can lead to desiccation. Both conditions can result in mortality of the larvae or unemerged adults. In my rearing setup, I use fiber drums ranging from 10-G to 50-G in size (I accumulated them from the dumpster where I work—mostly fiber drums used as shipping containers for bulk powders). Fiber drums are ideal because they not only breath moisture but are sturdy and may be conveniently stacked. Cardboard boxes also work as long as they are sturdy enough and care is taken to seal over cracks with duct tape. Avoid using plastic containers such as 5-G pickle buckets unless you are willing to cut ventilation holes and hot-glue fine mesh over them. While breathable containers usually mitigate problems with too much moisture, desiccation can still be a problem. To manage this, remove wood from containers sometime later in the summer (after most emergence has subsided), lay it out on a flat surface such as a driveway, and hose it down real good. Once the wood has dried sufficiently it can be placed back in the container; however, make sure the wood is completely dry or this will result in a flush of mold. I generally also wet down wood again in late winter or early spring, since I tend to hold wood batches through two full seasons.

I like to check containers every 7–15 days during spring and summer. Some people cut a hole in the side of the container that leads into a clear jar or vial—the idea being that daylight will attract newly emerged adults and facilitate their collection. I’ve tried this and was disappointed in the results—some of the beetles ended up in the vial, but many also never found their way to the vial and ended up dying in the container, only to be found later when I eventually opened it up. This is especially true for cerambycids, many of which are nocturnal and thus probably not attracted to daylight to begin with. My preference is to open up the container each time so that I can check the condition of the wood and look for evidence of larval activity (freshly ejected frass on the branches and floor of the container). I like to give the container a ‘rap’ on the floor to dislodge adults from the branches on which they are sitting, then dump the container contents onto an elevated surface where I can search over the branches and through the debris carefully so as not to miss any small or dead specimens. I use racks of 4-dram vials with tissue packed inside each and a paper label stuck on top of its polypropylene-lined cap as miniature killing jars. Specimens from a single container are placed in a vial with a few drops of ethyl acetate, and I write the container number and emergence date range on the cap label. Specimens will keep in this manner until they are ready to be mounted weeks or months (or even years) later. If the vial dries out, a few drops of ethyl acetate and a few drops of water followed by sitting overnight is usually enough to relax the specimens fully (the water relaxes the specimens, and the ethyl acetate prevents mold if they need to sit for a while longer).

I store my containers in an unheated garage that is exposed to average outdoor temperatures but probably does not experience the extreme high and low temperatures that are experienced outdoors. In the past I wondered if I needed more heat for wood collected in the desert southwest, but I never came up with a method of exposing the containers to the sun without also having to protect them from the rain. Metal or plastic containers might have eliminated this problem, but then breathability would again become an issue. I would also be concerned about having direct sun shining on the containers and causing excessive heat buildup inside the bucket that could kill the beetles within them. Now, however, considering the success that I’ve had in rearing beetles from wood collected across the desert southwest—from Brownsville, Texas to Jacumba, California, this seems not to be a big issue.

If anybody else has tips for rearing wood-boring beetles that they can offer, I would love to hear from you.


Bellamy, C. L. 2002. The Mastogenius Solier, 1849 of North America (Coleoptera: Buprestidae: Polycestinae: Haplostethini). Zootaxa 110:1–12 [abstract].

Lingafelter, S. W. 2007. Illustrated Key to the Longhorned Woodboring Beetles of the Eastern United States. Special Publication No. 3. The Coleopterists Society, North Potomac, Maryland, 206 pp. [description].

MacRae, T. C. 2003. Agrilus (s. str.) betulanigrae MacRae (Coleoptera: Buprestidae: Agrilini), a new species from North America, with comments on subgeneric placement and a key to the otiosus species-group in North America. Zootaxa 380:1–9 [pdf].

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

Copyright © Ted C. MacRae 2014

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