Finally, after nearly 40 years, I’ve gotten my weevil collection organized and inventoried—nearly 1,000 specimens representing 160 species from the USA, Mexico, Brazil, Argentina, and South Africa. My sincere thanks to Bob Anderson, weevil specialist at the Canadian National Collection, for looking at my specimens and providing identifications.
I belong (or used to belong) to several Facebook groups frequented by insect collectors—both professional and amateur. One question that frequently comes up—primarily for collections with species organized by unit trays—is how to deal with species identification labels. Not surprisingly, the opinions are as varied as the collectors. Some like to put a label on each specimen, while others put a label only on the lead specimen of a series. Some also print or write a separate header label that is placed in the unit tray. What about when names change? Or when reexamination of the specimen(s) reveals an erroneous ID? Should you remove outdated or erroneous identification labels? Fold them? Turn them upside down? Remove them altogether? These questions may seem trivial if one deals only with their own personal collection, but they become much more important when identifying specimens in institutional collections accessible to the public.
Here is my philosophy: an identification is a hypothesis, not data. As a result, ID labels are fundamentally different from labels indicating locality, date, ecological information, and collector, which are data—immutable and unchanging. Identifications can be “wrong” or may change over time, but regardless they merely reflect an individual’s opinion based on their level of expertise and familiarity with state of taxonomy and nomenclature at the time the identification was made. It then follows that identification labels do not need to be placed on every specimen—if a specimen without an ID label gets separated from the series, it does not result in a loss of data in the way it does for a specimen without a locality label, nor do old ID labels need to be changed as a result of nomenclatural changes or corrected identifications—a new label may be added (especially if it is an ID correction), but the old label should not be removed.
Almost as bad as removing old ID labels is folding them, which not only makes them difficult to read but results in mutilation—not just from the fold itself but also from the additional pin holes that are added when re-pinning the folded label. Old ID labels, even if incorrect or out-if-date, represent a historical record of opinion regarding the identity of the specimen, and degrading the labels obscures that history. If one simply must do something to denote a corrected ID, the old label may be turned over, but even then every effort should be made to reuse existing pinholes—just flatten with a fingernail before reusing so the label doesn’t spin. Seriously, however, this simply isn’t necessary—just add the new ID label beneath the old one, which denotes it as the more recent ID (another reason why year should be included on ID labels). Some people don’t like the way this looks, but to do otherwise is to greater priority on visual aesthetics than the integrity of the scientific data represented by the specimen.
As for dealing with nomenclatural changes—I don’t, at least not with already labeled specimens. That old ID label is not “wrong”—it accurately reflects the ID that was given to the series at the time the specimens were identified. Of course, any additional specimens that are added to the unit tray will receive an ID label the reflects the newer nomenclature. Case in point is the above photo, which contains longhorned beetles known for many years as Cosmosalia chrysocoma but recently reassigned to the genus Lepturobosca. You’ll note the older series of specimens bear ID labels with the older name, but the most recently added series contains an ID label with the newer name. There is no reason to go back and change or add ID labels for the older specimens, especially since newer specimens reflecting current nomenclature have been placed in the same unit tray with them. The mix of ID labels representing past and present nomenclature is not problematic—in fact, it adds historical perspective to the series as a whole. On the other hand, were I to receive a series of specimens labeled with an older name from another collection, I would be inclined to add my own, more current ID label (and would certainly do so if the ID—current nomenclature or not—was incorrect), since it was the result of subsequent examination by a different specialist.
Lastly, I don’t waste time creating header labels for unit trays—the ID labels on the specimens themselves are enough to indicate the identity of the species, and the time required to update header labels when nomenclature changes is just that much less time that I have to pin, label, and identify additional specimens being added to the collection.
In any insect collection, space is expensive and, thus, almost always at a premium—especially a large, self-funded, private collection such as mine. As a result, I am constantly looking for creative ways to maximize space efficiency. The photo here shows a technique I’ve adopted that works especially well for “leggy” beetles. Rather than lining them up “knee-to-knee” and wasting space between the specimens, I line them up “knee-to-elbow” by orienting every other specimen head downward. Of course, one can always simply tuck the legs and antennae underneath the body. However, this manner of mounting not only obscures the underside, but, in my opinion, looks rather sloppy and aesthetically unpleasing.
I have a few other tricks I use to maximize not only space in my collection but also its athletics that I may show here in future posts. However, if you have tips and tricks of your own, I’d love to hear them in the comments below.
I’ve been collecting insects for a long time. A really long time… like, almost my whole life! In the beginning, as a child and adolescent, I collected everything—a so-called “general collector.” Sadly, none of the collections I made during those formative years survived—lost to curious cats and benign neglect. I loved hunting for insects but hadn’t yet learned the importance of collection maintenance and preservation. This changed once I began taking entomology courses in college, and in fact the oldest personally-collected insects in my present collection are from my Entomology 201 “Introduction to Entomology” course taken during my junior year in 1978.
Entering graduate school in 1980 began my next phase as a collector—learning to specialize. With more than three-quarters of known life on earth being represented by insects (and perhaps, conservatively, 95% when considering all the not yet discovered species of insects), attempting to build a collection focused on all groups of insects is barely less ambitious—or feasible—than attempting to build a collection representing all life on earth!* If one wishes—as I did—to make meaningful contributions to insect taxonomy, they must specialize in a particular group—typically a family but sometimes even more restricted to certain subfamilies, tribes, or even genera. Although I was still not quite ready to narrow my focus to that degree, I was already leaning towards beetles, especially longhorned beetles (family Cerambycidae) (this despite the fact that leafhoppers were my thesis subject).
* I am reminded at this point of the quote by Oliver Wendell Holmes, who, when asked if he was an entomologist, replied “No man can be truly called an entomologist, sir; the subject is too vast for any single human intelligence to grasp.” In ‘The Poet at the Breakfast Table: II’, The Atlantic Monthly (Feb 1872), 29, 231.
My interest in longhorned beetles grew even stronger after I finished my degree and began working as a field entomologist for the Missouri Department of Agriculture. Part of my responsibilities included detecting, identifying, and providing recommendations for control of insect infestations in commercial nurseries. Woodboring beetles—primarily longhorned beetles but also jewel beetles (family Buprestidae)—were among the most difficult to control and, to me, interesting of the nursery pests that I encountered. These quickly gelled as my focus groups, and nearly 40 years later I still study them seriously, although for various reasons I eventually began focusing my primary efforts on jewel beetles while working on longhorned beetles as a secondary interest.
If, by now, you have the impression that I stopped collecting insects in other groups, you would be mistaken. While I may have been (somewhat) successful in focusing my studies on woodboring beetles (let’s forget for now my later diversions into tiger beetles—family Cicindelidae), I have been spectacularly unsuccessful in restricting my collecting activities just to those groups of insects. For years after I ‘supposedly’ specialized in woodboring beetles, I continued collecting insects in other groups—primarily but not exclusively beetles, and the farther afield I go from my home state of Missouri, the less discriminating I become when it comes to deciding what insects to place in the bottle. Of course, while I pin and label all the specimens I collect in these other groups, I cannot effectively work with them; with rare exceptions, I lack the knowledge, literature, and reference materials necessary to identify the specimens or, more importantly, synthesize and disseminate the findings to the broader scientific community. Thus, the specimens accumulate in my cabinet—waiting to be seen by somebody with the knowledge to determine their significance. Until that happens, the knowledge they represent is locked away; hidden.
In recent years, I have begun making an effort to change that. Four+ decades of being a serious insect collector has given me the opportunity to establish relationships with entomologists whose specializations run the gamut. Each of them could make far greater use of the specimens I have collected in these other groups than I ever will, and I have begun reaching out to them offering access. The photos shown here represent one such group—the leaf beetles (family Chrysomelidae). It has been more than 30 years since anybody specializing in this group has looked at the specimens I’ve collected, and in that time I’ve not only collected numerous specimens from my home state of Missouri but also from extensive collecting trips across the U.S., Mexico, South America, and even Africa—enough to fill six Schmidt-sized boxes! Surely, within this amount of material, there are specimens representing significant records or possibly even new species and just waiting for a discerning eye to spot them. Shawn Clark at Brigham Young University graciously identified the specimens in these boxes, and in return for his efforts he was allowed to retain anything of interest to his research.
A similar situation exists for other groups of insects that I have accumulated a wealth of specimens over the past several decades: click beetles (family Elateridae), currently being examined by Paul Johnson at South Dakota State University; darkling beetles (family Tenebrionidae), currently being examined by Aaron Smith at Purdue University; and weevils (family Curculionidae), currently being examined by Robert Anderson at the Canadian National Collection.
It should be noted that, eventually, my entire collection will end up in a public research collection, where it will be accessible at any time to any researcher. Nevertheless, I still take satisfaction in knowing that I don’t have to die before significant specimens in my collection belonging to groups that I don’t study can come to light.
Chrysomelidae Box 1—Missouri 1.
Chrysomelidae Box #2—Missouri 2, Michigan, Connecticut, North Carolina, Georgia.
Hot on the heels of the previous installment in this series, I present the sixth “Collecting Trip iReport”; this one covering a trip to Arizona during July/August 2018 with Art Evans and—like the previous installments in this series—illustrated exclusively with iPhone photographs (see previous installments for 2013 Oklahoma, 2013 Great Basin, 2014 Great Plains, 2015 Texas, and 2018 New Mexico/Texas).
This trip was a reunion of sorts—not only had it been 20 years since I’d collected in Arizona, it had also been 20 years since I’d spent time in the field with Art Evans—which just happened to be in southeast Arizona! For years I looked forward to our next opportunity, and when he told me of his plans for an extended trip to take photographs of his forthcoming Beetles of the Western United States, I couldn’t pass up the chance. Art had already been out west for five weeks by the time I landed in Phoenix on July 28th, and together we drove to Cave Creek Canyon in the Chiricahua Mountains and spent the night before beginning a 7-day adventure in and around the “Sky Islands” of southeastern Arizona.
As with the recent New Mexico/Texas post, the material collected still has not been completely processed and curated, so I don’t have final numbers of taxa collected, but there were a number of species—some highly desirable—that I managed to find and collect for the first time, e.g., the buprestids Acmaeodera yuccavora, Agrilus restrictus, Agr. arizonicus, Chrysobothris chiricauhua, Mastogenius puncticollis, and Lampetis webbii and the cerambycids Tetraopes discoideus and Stenaspis verticalis. Who knows what as-yet-unrecognized goodies await my discovery in the still unprocessed material?!
Day 1 – Chiricahua Mountains, Cave Creek Canyon
After arriving at Cave Creek Ranch late last night, we awoke to some stunning views right outside our room!
The first buprestid of the trip was a series of Pachyschelus secedens on Desmodium near Stewart Campground. We beat the oaks and acacia along the way to Sunny Flat Campground but didn’t find much. Once we got near Sunny Flat I did some sweeping in an area with new growth of Helianthus sp. and got a series of Agrilus huachucae, a few lycids, and one Leptinotarsa rubiginosa. I beat one Acmaeodera cazieri from Acacia greggii and found another on flower of prickly poppy (Argemone sp.). On the roadside at Sunny Flat I found several Acmaeodera spp. on a yellow-flowered composite – one A. rubronotata, one A. solitaria(?), and three A. cazieri. Also collected one A. cazieri on a rain gauge, Mecas rotundicollis and one as yet undetermined acanthocinine cerambycid on miscellaneous foliage, one tiger beetle (Cicindela sedecimpunctata?) on the roadside, and two orange lycids in flight.
Desert flats east of Portal, Arizona
We came to this spot to look for Sphaerobothris ulkei on joint-fir (Ephedra trifurca), but after not finding any for awhile I got distracted by some big buprestids flying around. Caught several Hippomelas sphenicus, one Gyascutus caelatus, and two Acmaeodera gibbula on Acacia rigida, and the first and third were also on Prosopis glandulosa along with Plionoma suturalis. We finally found S. ulkei – searched the area for almost three hours, and Art and I each caught two and Margarethe caught one – also one each of P. suturalis and A. gibbula. I also got a mating pair of A. gibbula on Acacia greggii. After dinner, we went back and placed an ultraviolet light – checked it a couple hours later and got a nice series of Cylindera lemniscata and a few meloids (for Jeff).
Day 1 of the trip ended in typical monsoon fashion – heavy, thunderous rainstorms moved into the area during late afternoon, dimming prospects for blacklighting. Still, we set them up anyway at several spots and checked them later in the evening (flood waters preventing us from going to all the spots we wanted to). Not surprisingly, the one trap that yielded interesting specimens was in the lowest (warmest) area and received the least amount of rain. For me it was a nice series of Cylindera lemniscata.
Day 2 – Southwestern Research Station, Chiricahua Mountains, Arizona
There is a large stand of a narrow-leaved milkweed (Asclepias sp.) at the station, so we stopped by in our way up the mountain to check it for beetles. Got a nice little series of Tetraopes discoideus (tiny little guys!) on the stems as well as a few Rhopalophora meeskei, two Lycus spp., and one Pelonides humeralis on the flowers.
At the Southwestern Research Station with Barbara Roth, Art Evans, and Margarethe Brummermann.
Road from Southwestern Research Station to Ruster Park After leaving the SWRS on our way up to Rustler Park, we stopped to check a couple of bushes of New Mexico raspberry (Rubus neomexicanus). Margarethe thought there might be lepturines on the flowers, but instead we found a few Acmaeodera spp. and some Rhopalophora meeskei.
Further up the road we made another quick stop to check roadside flowers – just a single A. rubronotata on a yellow-flowered composite, but spectacular views of the valley below.
Gayle Nelson once told me about finding Chrysobothris chiricahuae on pine slash at Rustler Park, so I was pleased to see several fresh slash piles when we arrived. I saw a Chrysobothris (presumably this species) on the very first branch in the very first pile that I looked at, but I missed it (damn!) and didn’t see any more in that pile. However, in the next pile I visited I saw two and got them both. I looked at a third pile and didn’t see any, nor did I see any more on the two previous piles that I looked at. Still, two is better than none (assuming this is, indeed, what they are!).
Chiricahua National Monument
Not a bug collecting stop, but we wanted to drive into the monument and see the incredible rock formations which are best appreciated by driving through Bonita Canyon and then up to Massai Point. The unusual spires, columns, and balancing rocks are a result of erosion through vertical cracks in the compressed volcanic ash which was laid down in layers 25 million years ago and then uplifted. Tilting during uplift caused vertical fractures and slippage, into which water then worked its way to create today’s formations. One of the columns I saw is 143 feet tall and only 3 feet in diameter at one point near the base! Mexican jays were our constant, close companions as we hiked through the pinyon pine/oak/juniper woodland.
Vicinity Gleeson, Arizona
There is a wash across N Ghosttown Trail with stands of Baccharis sarothroides growing along the sides. Art previously collected a single Cotinis impia on one of the plants, so we came back to check them. We didn’t find any, but we did find two fine males and one female Trachyderes mandibularis on a couple of the plants. I also found a dead Polycestaaruensis.
Vicinity Tombstone, Arizona
Art saw Gyascutus caelatus here previously, so we came back and found them abundantly in sweet acacia (Acacia rigidula), which was in full bloom. They were extremely flighty and hard to catch, so we each got only four. I also collected one Stenaspis solitaria on the same and a Trachyderes mandibularis female in flight.
At another spot nearby, we stopped to look for Lampetus webbii, which Art had seen but not been able to collect when he was here a couple of weeks ago. We did not see any (but read on…), and I saw but did not collect a Trachyderes mandibularis and two Stenaspis solitaria. I also saw and photographed some giant mesquite bugs (Thasus neocalifornicus).
The day ended enjoying steaks, Malbec, and Jameson with two of the best hosts ever!
Day 3 – Box Canyon, Santa Rita Mountains, Arizona
Our first stop of the day was Box Canyon, a gorgeous, rugged canyon on the east side of the range. Mimosa dysocarpa was in bloom, off which I beat two Agrilus aeneocephalus, several Hippomelas planicauda, and one Stenaspis solitaria. Norm gave me an Acmaeodera cazieri that he’d collected on an unidentified yellow-flowered composite, and right afterwards I found some small, low-growing plants with purple flowers and sticky leaves (eventually ID’d as Allionia incarnata, or trailing four o’clock) to which Acmaeodera yuccavora and A. cazieri were flying in numbers. After that I crawled up top and beat the mesquites, getting one Chrysobothris sp., a mating pair of S. solitaria, and a couple of large clytrine leaf beetles.
Vicinity Duquesne, Arizona
We came here to look for Tetraopes skillmani (this is the type locality). We found the host plant (Sarcostemma sp.), but there were no beetles to be seen anywhere. Maybe another location nearby…
Patagonia Pass, Patagonia Mountains, Arizona We went up higher into the mountains to get into the oak woodland, where I hoped to find some of the harder-to-collect oak-associated Agrilus spp. Right away I beat one Agrilus restrictus off of Emory oak (Quercus emoryi), but no amount of beating produced anything more than a single Enoclerus sp.. I also beat the Arizona oak (Q. arizonica) and got only a single Macrosaigon sp. On Desmodium sp. I collected not only Pachyschelus secedens but a nice series of Agrilus arizonicus. For me it is the first time I’ve collected either A. restrictus and A. arizonicus, the former being quite uncommon as well, so all-in-all not a bad stop.
Sycamore Canyon, Santa Cruz Mountains, Arizona
We came here for night lighting, but while we still had light I did some sweeping in the low vegetation and collected a mixed series of Agrilus arizonicus (on Desmodium sp.) and Agrilus pulchellus – the latter a first for me, along with two small cerambyids that could be Anopliomorpha rinconia. Conditions were perfect (warm, humid, and no moon), and we had lots of lights (Art’s five LED units, Steve’s MV/UV combo setup, and my UV setup), but longhorned beetles were scarce – just one Prionus heroicus and one Lepturges sp. for me, and Steve got a few others including a nice Aegomorphus sp. I did also collect a few scarabs – Chrysina gloriosa and Strategus alous – because they’re just so irresistible!
Day 4 – Prologue One of the downsides (if you can call it that) of having great collecting is the need to take periodic “breaks” to process all the specimens and make my field containers available for even more specimens. Thanks to Steve and Norm for making their place available to Art and I so we can do this before heading out to our next set of localities.
Copper Canyon, Huachuca Mountains, Arizona
Copper Canyon is the classic spot for finding the charismatic Agrilus cavatus (see photo), but first we did some sweeping in the low vegetation near the parking area, where Norm got one Agrilus arizonicus and two Agrilus latifrons – and gave them to me! (Thanks, Norm!) I did some beating of the oaks, and after much work I ended up with a single Agrilaxia sp. and pogonocherine cerambycid on Emory oak (Quercus emoryi) and a couple of giant clytrines on the Arizona oak (Q. arizonicus). I then started sweeping the low-growing Acaciella angustissima – right away I got two A. cavatus. They were in the area past the cattle guard on the right where lots of dead stems were sticking up, and although I continued to sweep the plants more broadly in the area I never saw another one. Finally, Norm called me up to a small Mimosa dysocarpa near the car off which he collected three Agrilus elenorae – and gave them to me! (Thanks, Norm!) I gave the tree a tap and got one more, and in my last round of sweeping I came up with a Taphrocerus sp. (must be some sedges growing amongst the grasses).
Bear Canyon Crossing, Huachuca Mountains, Arizona
There was quite a bit of Mimosa dysocarpa in bloom along the roadsides on the west side of the Bear Canyon crossing, which I beat hoping to find some more Agrilus elenorae. I didn’t find any, but I did get several more Hippomelas planicauda, which is a nice consolation prize – and a great photo of the last one! Other than that I did a lot of sweeping and found only a single Acmaeodera cazieri.
Appleton-Whittell Research Ranch of the National Audubon Society, Elgin, Arizona
Cool temperatures and a blustery wind discouraged most insects from finding our blacklights. However, our blacklight did find some other interesting local residents. These two individuals could be the stripe-tailed scorpion, Paravaejovis (Hoffmannius) spinigerus, a common species in Arizona and southwestern New Mexico.
Day 5 – Miller Canyon Recreation Area, Huachuca Mountains, Arizona
There was a lot of Baccharis sarothroides growing in the lower canyon near the parking area, so I checked it all out hoping to find Tragidion annulatum. None were seen, and in fact there was very little insect life in general. I did pick up a couple of Acmaeodera solitaria by sweeping – not anything significant but the 15th species buprestid of the trip and found a dead Cotinis mutabilis, and Art got a nice series of Chalcolepidius click beetles on B. sarothroides and Prosopis glandulosa. Puzzling the lack of insect activity, given how green all the plants were and how fresh the growth looked. I guess we’ll have to look elsewhere.
Vicinity Naco, Arizona
We decided to try some desert thorn-scrub habitat so headed east towards Bisbee. Just north of Naco we saw some habitat where it had rained recently – everything was green with the sweet acacia (Acacia rigidula) and creosote (Larrea tridentata) in full bloom. Immediately out of the car I found a Dendrobias mandibularis on Baccharis sarothroides (and when I came back to it later I found a big, major male on it – see photos). On the sweet acacia we found a handful of Gyascutus caelatus (one of which I got a nice photo of), a mating pair of Sphaenothecus bivittatus, and a Cymatodera sp. Finally, out along the roadsides a riot of different yellow composites were in full bloom, including Heliomeris longifolia off which Art got a couple of Acmaeodera solitaria and I got two specimens of a large Acmaeodera sp. (blue-black with numerous small irregular yellow spots).
Vicinity Tombstone, Arizona
We decided to go back to the spot north of Tombstone where Art had earlier seen Lampetis webbii and give that species another shot. We looked at the Rhus sp. tree that he’d seen them on, and then we each followed the wash in opposite directions looking at the Rhus trees along them, which growing above the banks but never further away than about 25 feet. Along the way I collected several more Gyascutus caelatus on sweet acacia (Acacia rigida), which were more abundant this time than last and also easier to catch. After walking about 1/4-mile down the wash I saw something fly from a Rhus tree and land low on the bushes nearby. I quickly netted it, pulled it out, and was elated to see that it was, indeed, Lampetis webbii! I searched the Rhus in the area more carefully but didn’t find any more, then found some Rhus growing up along the road. At one point, I saw a large buprestid fly and land high in the top of another Rhus tree. I couldn’t tell for sure if it was L. webbii, but I extended my net as far as I could, positioned it beneath the beetle, and tapped the branch hoping it would fall in. Unfortunately, it flew away instead of dropping, so I can’t say for sure whether it was L. webbii or just a wayward G. caelatus. At any rate, L. webbii is yet another species that I have not collected before now and the 17th buprestid species of the trip.
Ramsey Canyon, Huachuca Mountains, Arizona
After returning from Tombstone, we visited Pat & Lisa Sullivan at their home at the end of Ramsey Canyon. Pat is a scarab collector who runs lights at his home nightly, and after a delicious dinner we spent the rest of the evening checking the lights. I was hoping to collect Prionus heroicus, and I got my wish. Also got Prionus californicus and several other non-cerambycid beetles such as Chrysina beyeri, C. gloriosa, Lucanus mazama, and Parabyrsopolis chihuahuae (the latter a first for me). I also placed a prionic acid lure (thanks Steve!) and got three more male P. heroicus. We also hunted around the rocks and roadsides hoping to find Amblycheila baroni but didn’t find any. Art did, however, find a female P. californicus and gave it to me (thanks!).
Day 6 – Vicinity Sonoita, Arizona
Unsuccessful attempt to collect Hippomelas martini, only recently described (Bellamy & Nelson, 1998) and part of the type series taken somewhere near this spot (“20 mi NE Patagonia, Hwy 82”) by “sweeping roadside vegetation”. At other locations it had been recorded on Calliandra sp., and I found patches of the plant here along and on top of the road cuts. This gives me confidence that I found the right spot, but I didn’t encounter this or any other beetles by sweeping the patches or visually inspecting them.
Box Canyon, Santa Rita Mountains, Arizona
We decided to come back to Box Canyon since we’d had such good luck last time. I started at the spot above the dry falls where I collected so many Acmaeodera cazieri and A. yuccavora on flowers of Allionia incarnata. This time it was hotter, drier, and windier, and the flowers were semi-closed. Still I found a few of each. I then started walking down the road towards the lower canyon crossing where I would meet up with Art. Things were really hopping on the Mimosa dysocarpa, with Hippomelas planicauda abundant (finally collected my fill) and several other Buprestidae also beaten from the plants: Agrilus aeneocepahlus, Acmaeodera scalaris, Acmaeodera cazieri, Chrysobothris sp., and a species of Spectralia! (seven species of Buprestidae at one location I think is the high for the trip.) I checked other plants and flowers along the way down but didn’t find much.
Lower Madera Canyon, Santa Rita Mountains, Arizona
Madera Canyon is perhaps the most famous insect collecting locality in Arizona – maybe in the country, and it is hard to make a visit to Arizona without stopping by here. We elected to work the lower canyon first in an area where Chrysobothris chalcophoroides has been taken on Arizona oaks (Quercus arizonicus). Hiking towards the oaks I found some Stenaspis solitaria in a Baccharis sarothroides and marveled at the variety of other insects active on the plants (see photos) – later I would also collect an elaphidiine cerambycid on the plant. Next I started working the oaks, beating every branch I could reach with my net handle. With one whack of the stick a single Paratyndaris sp. and a single Brachys sp. landed on my sheet – those would be the only buprestids I would collect off the oaks! Other than that I collected one Hippomelas planicauda on Mimosa dysocarpa for the record. While I was working the oaks up in the knoll, the weather started turning with blustery winds, and I could see the rain coming in the distance. By the time I got down from the knoll the rain had arrived, and I walked back to the car in a sunny downpour using my beating sheet as an umbrella!
Montosa Canyon, Santa Rita Mountains, Arizona
Just to try something different, we went to Montosa Canyon – the next canyon south of Madera Canyon – for tonight’s blacklighting. We set my sheet up just E of the crossing and Arts ground units back to the west along a gravel road on the south side of the crossing. Moths came in numbers, but the beetles were light – I collected only blister beetles (Epicauta sp.) and a Cymatodera sp. checkered beetle at the sheet, a series of tiger beetles and a female Strategus cessus at the second ground unit, and a male Strategus aloeus and two Stenelaphus alienus at the third ground unit.
Day 7 (last day) – Vicinity Continental, Arizona
There was a photo posted on BugGuide of Stenaspis verticalis taken last week, so we decided to give it a shot and see if we could get lucky and find it ourselves. We checked all the Baccharis sarothroides within ½-mile if the spot but didn’t find it. I did, however, collect four Euphoria leucographa, two Chalcolepidius smaragdula, two Aneflus spp., and singletons of Stenaspis solitaria and Dendrobias mandibularis. I also took a couple of Hippomelas planicauda on Mimosadysocarpa – just for the record!
Lower Madera Canyon, Santa Rita Mountains, Arizona
We returned to work the lower canyon area. I’d heard that the tiger beetle Cicindelidia obsoleta santaclarae has been taken in the area last week so was hoping to run into it. While Art worked the east side of the road I worked the west, initially following FR-781 into what looked like grassland areas where the tiger beetle might occur. I didn’t see any but took Acmaeodera scalaris on Heterotheca sp. flowers and Acmaeodera solitaria on Argemone mexicana flowers. There was also a fresh wind-thrown mesquite (Prosopis glandulosa) with a bunch of Chrysobothris octocola and one Chrysobothris rossi on it. Still the area looked abused from grazing and was uninteresting, so I looked for another area to explore.
Northwest of the parking lot I spotted another grassy area that was dotted with Baccharis sarothroides, so I decided to give that area a look. After clambering several times through barbed wire fence, I reached the area and began to give it a look. Still no tiger beetles, but every time I passed a B. sarothroides I inspected it closely. I’d looked at several plants when I came upon one with a Stenaspis solitaria sitting in the foliage, and when I looked down on one of the stems and saw a big male Tragidion sp. on the underside of the stem. After securing it, I looked closer at the plant and saw a pair of annulated antennae crawling up another stem – I knew right away it was a mating pair of Stenaspis verticalis! After carefully moving to the other side to confirm, I dared to take a few photos in situ (see below) and then secured the couple. Of course, this gave me newfound motivation to work the entire area to look for more. It was very hot by then, and I was already quite thirsty, but I summoned up all the stamina that I could and worked as many plants as I could, ending up with six Tragidion spp. and three Stenaspis verticalis. The latter was one of my top priority targets for this trips, and the only thing more satisfying than getting it is doing so on my last day on the field.
Montosa Canyon, Santa Rita Mountains, Arizona
We returned to Montosa Canyon and stopped at the Astronomy Vista partway up. It was hotter than bejeebuz! There was not an insect to be seen except giant cactus bugs and a single Euphoria leucographa that Art found on a sapping Baccharis sarothroides. Temp was 103°F even at this elevation!
We needed to escape the heat, and I wanted to see oaks for one more crack at Mastogenius, so we drove up to the 13-km marker and I collected on the way back down to below the 12-km marker. Conditions were much more agreeable (temps in the 80s), and near the top there was a Ceanothus sp. bush in bloom, off which I collected Rhopalophora meeskei and Stenosphenus sp. – both genera represented by individuals with black versus red pronotum. Then I started beating the (Mexican blue, I believe) oaks, and right away I got a Mastogenius sp.! Kinda small, so I’m thinking not M. robusta and, thus, probably M. puncticollis (another species new to my collection). I also beat a largish Agrilus sp. that I don’t recognize, a few clerids, two R. meeskei, one Stenosphenus sp., and a couple of leaf beetles. There was also another type of oak there – Arizona white, I believe, which I beat as well but only got one clerid.
We stopped by the Astronomy Vista again on our way back down the canyon, and I found a pair of Moneilema gigas on cholla (Opuntia imbricata).
It was a fantastic seven days in the field with Arthur, and it was a great pleasure to (in some cases, finally) meet Margarethe, Barbara, Steven, Norm, and Pat. I appreciate the warmth, generosity, and hospitality that all of them displayed to me and look forward to our next encounter, hopefully in the near future. Now, for some light reading during the plane ride home!
During my February/March 2015 visit to Argentina, I had the opportunity to travel to west-central provinces of San Juan and San Luis with Federico Ocampo for a weekend of insect collecting. Up to that point most of my collecting in Argentina had been limited to the northeastern provinces (Chaco, Corrientes, and Misiones), so I was excited for the chance to explore a radically different biome. West-central Argentina represents a transition zone from the flat, wet, treeless plains of the Humid Pampas in east-central Argentina (Buenos Aires, Santa Fe, and Córdoba Provinces) to the massive Andes Mountains running along the western edge of South America. This area is home to the Monte, a desert biome characterized by volcanic sediments, piedmont plains, large mountain blocks and dry salt lakes. Conditions in the Monte are generally more hospitable than in the neighboring Atacama and Patagonian Deserts lying north and south of the Monte, respectively. As a result, the flora and fauna in the Monte is relatively rich and characterized by a diversity of shrubs, grasses, and cacti.
Encón Dunes, San Luis Province, Argentina
Of the several sites we visited in the area, the most remarkable was “Las Dunas de Encón” (the Encón Sand Dunes) in San Luis Province. Belonging to a larger system covering some 250,000 hectares—the largest in South America (and, thus, sometimes called the “Argentinian Sahara”)—the dunes are thought to have formed some 100–200K years ago as a result of dry conditions brought on by Quaternary glaciations. I find sand dune systems endlessly fascinating due to their unique and often endemic plants and animals and have visited many systems in North America (Bruneau, Coral Pink, Glamis, Great, Medora, St. Anthony, and others), but this was the first sand dune system I’ve had the opportunity to see outside of the U.S. Federico, a scarab specialist, shares that fascination and has, in fact, described a number of species in the scarabaeine tribe Eucraniini—endemic to South America—that utilize these very sand dunes (Ocampo 2005, 2007, 2010). He was hoping one or more of them might be out and about; I was hoping to see anything, really.
Parkinsonia praecox? – adult host plant for Lampetis baeri and L. corinthia.
One of the first plants that caught my attention was a woody, fabaceous shrub that looked very much like what I would have previously called Cercidium, now Parkinsonia, and which after a bit of digging I conclude is likely Parkinsonia praecox. Woody, fabaceous shrubs in desert habitats are a sure bet to host jewel beetles, so I began paying special attention to each shrub as I wandered by. It wasn’t long before I saw a large, brilliant metallic green jewel beetle sitting on an outer branch of one of the shrubs—it was one of the most beautiful jewel beetles I have ever seen out in the field with my own eyes! I managed to catch it, and over the next few hours I collected not only several more of this species but also several individuals of an even larger, more somber-colored species. I was able to identify them as Lampetis baeri (Kerremans, 1910) and L. corinthia (Fairmaire, 1864), respectively, when I compared them to material in the collections at Fundacion Miguel Lillo, Instituto de Entomologia, Tucuman, Argentina [IFML]) during my visit there the following week (see photos below).
Lampetis baeri (Kerremans, 1910) [IFML]
Lampetis corinthia (Fairmaire, 1864) [IFML]
As a jewel beetle enthusiast, you would think that was the highlight of my day. In fact, the fun had only started. For a time after our arrival, Federico pointed out burrows likely made by eucraniine adults, but we didn’t see any evidence of activity at first. It wasn’t long, however, before we found the first adult—a fine Eucranium beleni Ocampo, 2010, the largest of the three species occurring at this site (about the size of our North American Deltochilum). One of the more obvious features of eucraniines is their enormously enlarged forelegs and pronotum to hold the musculature required to carry—that’s right, carry!—provisions to the larval burrow (in contrast with the more commonly seen habit among members of the subfamily of using the hind legs to push provisions to the burrow). This unusual morphology gives these beetles not only an amusing, shuffling gait but also a rather comical method for turning themselves upright (as seen in this video narrated by Federico). There are other dung beetles that pull, rather than push, larval provisions (e.g., Sisyphus spp., which stand on highly elongate hind legs and walk backwards while pulling the dungball), but eucraniines seem to be the only ones that actually lift provisions off the ground to carry them. In the case of E. beleni, this involves carrying pieces of dung with the forelegs held out in front of the head while walking forward on the middle and hind legs (Ocampo 2010). I didn’t get to see that behavior with E. beleni, but I did see it with one of another of the eucraniines we found that day (see below). In the E. beleni photo below, note the brushy middle and hind tarsi—an adaptation for walking on loose sand.
Eucranium belenae Ocampo, 2010 walks on its middle/hind legs while holding its forelegs aloft.
Eucranium belenae burrow plugged with a piece of dung.
The second species in the group that we encountered was Anomiopsoides cavifrons (Burmeister, 1861). This species is much smaller than E. beleni (about the size of a large Onthophagus), and unlike E. beleni—and, in fact, most other dung beetles—the larvae of A. cavifrons develop on plant matter rather than dung. Both males and females provision the larval burrows with pieces of plant debris that they pick up with their front legs and carry back to the burrow while walking on their other four legs. This rather amusing video shows a male bringing a piece of debris back to his burrow, then exiting to find and retrieve another piece of debris to bring back to the burrow. The molar region of their mandibles is heavily sclerotized for masticating the plant fibers in preparation for the larvae. There are a couple of other species in the tribe that opportunistically include plant matter in their diet, but A. cavifons seems to be the only one known to utilize dry plant matter in desert habitats almost exclusively (Ocampo 2005). Anomiopsoides cavifrons was far more abundant in the dunes than E. beleni, and by early to mid-afternoon they were encountered with such regularity that I stopped even looking at them.
Anomiopsoides cavifrons (Burmeister, 1861) male at burrow entrance.
We also were fortunate to see a few individuals of the third species known from these dunes, Anomiopsoides fedemariai Ocampo, 2007. This species is intermediate in size between the extremes represented by E. beleni and A. cavifrons and utilizes pellets of the plains viscacha (Lagostomus maximus), a species of rodent in the family Chinchillidae, for food (Ocampo 2007).
Ocampo, F. C. 2005. Revision of the southern South American endemic genus Anomiopsoides Blackwelder, 1944 (Coleoptera: Scarabaeidae: Scarabaeinae: Eucraniini) and description of its food relocation behavior. Journal of Natural History 39(27):2537–2557 [pdf via DigitalCommons].
Ocampo, F. C. 2007. The Argentinean dung beetle genus Anomiopsoides (Scarabaeidae: Scarabaeinae: Eucraniini): description of a new species, and new synonymies for A. heteroclyta. Revista Sociedad Entomología Argentina 66(3–4):159–168 [pdf via SciELO Argentina].
Ocampo, F. C. 2010. A revision of the Argentinean endemic genus Eucranium Brullé (Coleoptera: Scarabaeidae: Scarabaeinae) with description of one new species and new synonymies. Journal of Insect Science 10:205, available online: insectscience.org/10.205 [pdf via DigitalCommons].
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.
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.
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 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, 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 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):
* 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.
I’ve been a student of insects for most of my life, and of the many aspects of entomology that interest me, field collecting and identification remain the most enjoyable. My interest in beetles first began to gel during my days at the university (despite a thesis project focused on leafhoppers), and early in my career I settled on wood-boring beetles (principally Buprestidae and Cerambycidae) as the taxa that most interested me. To say that species identification of these beetles can be difficult is an understatement, but I was fortunate to have been helped by a number of individuals—well-established coleopterists—who freely shared their time and expertise with me during my early years and pointed me in the right direction as I began to learn the craft. Some of the more influential include colleagues that have since passed (e.g., Gayle Nelson, John Chemsak, Chuck Bellamy, and Frank Hovore) and those that, thankfully, continue with us (e.g., Rick Westcott and Henry Hespenheide).
It has been a little more than 30 years now since I began studying these beetles, and due in great part to the help I received early on and the motivation that it inspired within me, I have gained a certain amount of proficiency in their identification as well. Not surprisingly, I too regularly receive requests from people looking for help with identifications. I rarely turn down such requests (in fact, I don’t think I have ever turned one down)—it not only helps my own research but also, occasionally, allows me to fill a gap or two in my collection. More importantly, however, it is my duty—I benefited greatly from those who shared their expertise with me, so it’s only fair that I continue by their example.
As common a practice as this is among collectors, it seems odd that there are few written guidelines on the etiquette of requesting and providing identifications. Note that this is something different than borrowing specimens for study, which has its own set of expectations and responsibilities. As someone who has both requested and received requests for specimen identifications for a long time now, I have my own thoughts about reasonable expectations in this regard. Perhaps you, too, will find these thoughts useful the next time you contemplate asking somebody to identify your specimens (or accepting a request to do so).
Guidelines for requesting identifications
Always ask permission to send specimens before doing so. ‘Nuff said.
Leave extra room in the specimen box. While tightly packed specimens minimize shipment size and can reduce cost, it also increases risk of damage during shipment due to ‘bumping’ or during removal from the box for ID. More importantly, it allows little or no room for the addition of identification labels to specimens. Additionally, many identifiers find it helpful to remove all of the specimens from a box and group them by related taxa to facilitate identification. The reassembled specimens may require more space than they did in their original arrangement.
Send the entire available series of specimens. A common practice among those sending specimens for ID is to hold back specimens from a series and send only one or a few examples. Whether this is to, again, minimize the size of the shipment, confirm a provisional ID, or safeguard specimens perceived as desirable, it nevertheless prevents the identifier from having access to the range of data and variability represented in the series. This is important if the series contains 1) multiple species, 2) previously undocumented distributions or ecological data, or 3) unusual morphological variants. An exception to this is when very long series of specimens are available and sending the entire series would be unwieldy and/or unnecessary. In this case, the identifier should be informed that only a partial series of specimens was sent.
Allow retentions. It doesn’t happen often, but sometimes individuals have balked at my requests to retain specimens that proved useful for my studies. This is poor etiquette, as it shows little respect for the value of the service being provided by the person making the identifications. More common is to allow retention of examples from a series, but not singletons. This also, in my opinion, is poor etiquette. I remember one of my early sendings to Gayle Nelson that contained a single specimen of Agrilus audax, a very rare North American buprestid known by only a handful of specimens. Not surprisingly, Gayle did not have this species in his collection, and while I, too, was a student of the group I didn’t hesitate to give this specimen Gayle—established and well-respected expert of the family that he was. To this day the species remains unrepresented in my collection, yet I have never second guessed that decision due to the value of what I gained in his respect and mentorship in the years since. Most identifiers are both humble and sparing in their requests for retentions.¹
Allow time for identifications. Individuals with expertise in a given group are generally few in number, and those willing to provide identifications may be fewer still. As a result, they usually have a number of boxes on hand at any one time awaiting identification. Get an idea from them at the start of how long they expect it will be before they can complete the task. If the projected timeline passes and you don’t hear back from them, an inquiry is fine, but be polite and understanding.
¹ A corollary to this asking for specimens in exchange for specimens retained. An exchange involves two parties sending each other specimens that mutually benefit each other’s collections. Identifications are a service provided by one party that benefit the requester. To suggest an exchange as ‘payment’ for retained specimens ignores the value of the service being provided by the identifier
Guidelines for providing identifications
Once specimens are received, protect them from damage as you would your own collection. Maintain them in a protective cabinet or check them regularly to ensure that dermestid pests do not gain a toehold.
Provide the identifications in as timely a manner as possible. This is not always easy, especially for those willing to accept a large number of requests and who may find themselves inundated with boxes awaiting identification. If you cannot provide identifications relatively quickly, be honest with the requestor regarding how long you expect the identifications to take. If it does take longer, provide an update to the requestor and give them the option to have the specimens returned or confirm that they are okay with the delay.
Add your identification label with your name and date (year) to at least the first specimen in the series. Even better is if you can add a small, pre-printed ID label to every specimen in the series, but this can be difficult if the number of specimens and/or diversity of species is large. If there are specimens with prior identifications that you disagree with, turn the prior ID label upside-down, replace through an existing pin hole, and add your ID label. I disagree with the practice of folding prior ID labels—not only could I be wrong, but this unnecessarily damages something with historical value, especially if new pin holes are added to the label. Always place your ID label below any existing labels (i.e., label order should reflect their sequence of placement—oldest labels nearest the specimen and newest labels furthest away).
Keep retentions to a minimum. I generally ask to retain specimens only when they significantly improve the representation in my collection or provide significant new data—i.e., un- or under-represented species, undocumented distributions or ecological data, etc. The bar for singletons is even higher—usually only if they are completely absent from my collection (with ~65% of U.S. Buprestidae now represented in my collection, this is an increasingly uncommon occurrence).
Following #4, provide an accounting of retained specimens. Minimally, a list of species and their number should be given, and my preference is to provide label data as well (especially if requested). I once sent a batch of beetles (in a family in which I do not specialize) to an expert for identification, and when I received them back it was obvious that a number of specimens had been retained (perhaps 1/3 of the total number). When I wrote to the identifier and asked for an accounting (remember, I was only asking for an accounting—I did not have a problem with the retentions themselves), I received a rather terse reply from the individual stating that he did not ‘have time’ to provide this. Needless to say, this level of dismissiveness was not appreciated, and I have since found another more agreeable researcher with expertise in that family to send specimens for identification.
Again, these guidelines are written from the perspective of a private individual sending and receiving specimens for identification. Scientists at institutions may have additional or differing guidelines on this subject, but in any case these guidelines should be communicated to and understood by individuals requesting identifications before any material is sent.
If you have additional suggestions or comments on how these guidelines can be improved I would appreciate hearing them.