Where do BitB readers come from (and why I like Facebook better than Twitter and Google+)?

/ Ted C. MacRae / 14 Comments

I’m not obsessed with blog stats, but every now and then it’s interesting to take a look and see what information I can glean from them. One of the stats provided by WordPress is “Referrers”—which sites readers came from. This is good information to know, as it can help guide decisions on which sites to put effort into as a referral site. It was precisely this stat that caused me to leave Google+ some months ago. I tried G+ for a time as an alternative to Facebook, cross-posting links to new posts and occasionally posting separate photos to maintain a consistent level of activity. But after several months I decided the interactions I was having on G+ weren’t very satisfying—no conversations about the subjects like what happens on Facebook, just brief comments of the “Nice shot” variety. Moreover, my WordPress Referrer stats showed virtually no traffic coming from G+. This was puzzling, as I found myself continually being added to G+ circles (thousands eventually, which in itself seemed very “spammish” to me), but since there was no automatic mechanism for linking new posts on G+ (like there is for Facebook and Twitter), I decided the tiny amount of traffic it drove was not worth the effort. I stopped posting to G+ (yet continued to be added to circles, which made me even more suspicious and eventually led me to deleting my G+ account altogether).

As my involvement with G+ waned, I became more involved with Twitter. I get Twitter—really, I do, although I had trouble getting it at first. It’s quick, it’s fun… it’s a great way to keep tabs on a lot of people who like to post links to things I am interested in. Nevertheless, I still find myself having trouble staying consistently involved with Twitter. My problem is the 140-character limit—again, I’m more interested in conversation than quips, and in this regard Facebook is a much less limiting—and thus more enjoyable—venue for interacting with like-minded individuals. I also find Twitter to be rather clumsy when it comes to sharing photos compared to Facebook’s more elegant (Google+ inspired?) model. If I can’t converse on Twitter the way I’d like to, then all I really have left to use Twitter for is to provide links to new posts on BitB. A few hundred followers may be modest, but one would still think it enough to drive a fairly good amount of traffic to the blog. Curiously, recent review of Referrer stats show this not to be the case. Over the past 30 days, only 43 visitors have come to BitB from Twitter—less than 1.5 per day! WordPress enables automatic linking of new posts on Twitter, so it doesn’t really take any effort on my part to maintain the account, but I still have to wonder if such little return warrants even this amount of effort.

Of course, search engines—primarily Google—reign supreme in driving traffic to BitB, with the past 30 days yielding 6,180 visits. But among non-search engine sites, where do most of my readers come from? Facebook! In the past 30 days, 232 visitors have clicked on a link to BitB through Facebook—either on my own page or that of somebody else who liked a post on BitB and provided a link to it. Considering how much fun I have on Facebook aside from providing links to posts on BitB—whether it be quick photos of experiences as they happen, enjoying photographs of other expert insect macrophotographers, or involvement in multi-party conversations about the finer points of insect taxonomy—the fact that it also drives a large amount of traffic to BitB almost seems like a bonus. People like to make fun of Facebook, and the recent exodus of many bug bloggers to Twitter and G+ cannot be ignored, but for me Facebook continues to be the supreme medium for online interaction.

I realize this a one-case study and don’t intend to generalize my experience to others. It does, however, raise some interesting questions. Why are Facebook users so much more likely to click on my links that Twitter or G+ users? What prompted thousands of G+ users to add me to their circles but almost none of them to actually click through to my content? Is my experience typical? Any insight on these questions would be appreciated.

I should also mention another significant referrer for BitB—Alex Wild. Combined stats from his Myrmecos and Compound Eye blogs over the past 30 days resulted in a cool 99 BitB referrals. While this is not quite at the same level as Facebook, it is remarkable for an individual blogger to be the source of so much traffic for my blog. I doubt Alex himself is responsible for all of these visits (although I’m sure he checks in from time to time), rather it is likely that a portion of the enormous reader base he has uses his sites as jumping off points for other bug blogs they like. No other bug blogger, and not even WordPress Reader or Blogger themselves, comes close to sending as much traffic to BitB as does Alex Wild. So, Alex… thank you!

Copyright © Ted C. MacRae 2013

“Rare jewel beetles discovered in Mexico by team of scientists!”

/ Ted C. MacRae / 2 Comments

I hope you’ll excuse the hyperbolic title, but such has been my impression with some of the headlines I’ve seen recently in the popular media regarding newly described insect taxa in various parts of the world. The “discovery” of new species in far away, tropical lands sounds exciting and ground-breaking to many people, who envision teams of scientists wearing pith helmets and cargo shorts machete-slashing their way through miles of virgin forest before stumbling into a secret biodiversity hot-spot, their weeks of toil and sweat finally paying off by becoming the first white men to lay eyes upon a bounty of strange, exotic, never-before-seen creatures. In reality, new species of insects are not at all hard to find—in fact, depending on where you go it can be downright easy. Admittedly the chances are greater in the tropics, where many areas remain little explored, but even in well-studied North America new species turn up regularly. This includes popularly collected beetles in the very well-studied eastern U.S., where I’ve already described one new jewel beetle (family Buprestidae) and one new longhorned beetle (family Cerambycidae) from right here in my home state of Missouri (MacRae 2000, 2003) and am in the process of describing another new jewel beetle. No, finding new species is easy—recognizing them as such is the hard part. That’s not to say that new species cannot be recognized when first encountered, but I suspect that a majority of new insect species aren’t actually “discovered” until they’ve been brought back from the field, curated, and sat in a cabinet for years or decades—unrecognized for what they really are due to resemblance to known species until somebody comes along and examines them more critically.

Such is the case with two jewel beetle species that Chuck Bellamy and I describe in a paper just published in The Pan-Pacific Entomologist (MacRae & Bellamy 2013). I joined Chuck on several trips to Mexico in 1992 and again from 2004–2006 to explore the tropical thorn woodlands in the southern states of Oaxaca, Puebla, Guerrero and Michoacán. Jewel beetle diversity is high in these still relatively intact woodlands, with a number of new species already having been described from the area in recent years, and all-told we collected well over 100 species. At least a dozen or more of these look to be new, and considering that the Mexican jewel beetle fauna as a whole includes more than 800 known species the actual number could greatly exceed 1,000. The two described in this most recent paper resemble the common, widespread species Actenodes calcaratus. This big, beautiful jewel occurs from the southwestern U.S. through Mexico and Central America to northern South America, developing as larvae in dead wood of a variety of fabaceous hosts. We collected several of what we thought was this species during our trips, but a number of subtle but consistent differences in punctation and surface sculpturing emerged as we began comparing them more critically against A. calcaratus from other locations. The coup de grâce, however, was the coloration of the male face—normal bronze in A. calcaratus (Fig. 5) and similar to the female (Fig. 6), but flash-green in male A. scabrosus (Fig. 2) and green-violaceous in male A. michoacanus (Fig. 8). It’s quite remarkable that both of these species differ from their more widespread relative by subtle morphological characters but such striking sexually dimorphic facial coloration, and we subsequently found a similar situation with another species in the genus (A. undulatus) that otherwise bears little resemblance to A. calcaratus.

Figs. 1–9. Actenodes spp. 1–3. Actenodes scabrosus. 1–2. Male holotype. 1. Dorsal habitus. 2. Frontal view. 3. Female paratype (Guerrero). 4–6. A. calcaratus. 4–5. Male (MEXICO, Guerrero, Hwy 95, 5 km S Milpillas, 7.vii.1992, "big dead tree", G. H. Nelson [FSCA]). 4. Dorsal habitus. 5. Frontal view. 6. Female (MEXICO, Hwy 95, 2 km S Milpillas, 6.vii.1992, on Acacia farnesiana, G. H. Nelson [FSCA]), frontal view. 7–9. A. michoacanus. 7–8. Male holotype. 7. Dorsal view. 8. Frontal view. 9. Female paratype, frontal view. All scale bars = 5 mm.

Figs. 1–9. Actenodes spp. 1–3. Actenodes scabrosus. 1–2. Male holotype. 1. Dorsal habitus. 2. Frontal view. 3. Female paratype (Guerrero). 4–6. A. calcaratus. 4–5. Male (MEXICO, Guerrero, Hwy 95, 5 km S Milpillas, 7.vii.1992, “big dead tree”, G. H. Nelson [FSCA]). 4. Dorsal habitus. 5. Frontal view. 6. Female (MEXICO, Hwy 95, 2 km S Milpillas, 6.vii.1992, on Acacia farnesiana, G. H. Nelson [FSCA]), frontal view. 7–9. A. michoacanus. 7–8. Male holotype. 7. Dorsal view. 8. Frontal view. 9. Female paratype, frontal view. All scale bars = 5 mm.

In the case of both of these new species, the first specimens were actually collected more than 40 years ago but remained “hidden” among specimens of A. calcaratus until we examined the collections containing them more closely. While it might seem that the striking male facial coloration both of these species exhibit should have resulted in their quick recognition as undescribed species, even seemingly obvious characters such as this can be overlooked when an otherwise great resemblance to a common, widespread species prevents their critical examination.

REFERENCES:

MacRae, T. C. 2000. Review of the genus Purpuricenus Dejean (Coleoptera: Cerambycidae) in North America. The Pan-Pacific Entomologist 76(3):137–169.

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.

MacRae, T. C. & C. L. Bellamy. 2013. Two new species of Actenodes Dejean (Coleoptera: Buprestidae) from southern Mexico, with distributional and biological notes on Buprestidae from Mexico and Central America. The Pan-Pacific Entomologist 89(2):102–119.

Copyright © Ted C. MacRae 2013

Observation and Bias in Biology

/ Kent / 11 Comments

The following is a guest post by my friend Kent Fothergill. Read more of Kent’s musings at his blog, biologistsoup.

Observation is a key activity in scientific inquiry. People who work with insects can make many interesting observations from collected insects: distribution, phenology, etc. Observations can be documented and analyzed later from photographs. A collection of photographs can also yield information about: associations with other species, behavior, while providing the same information as collected specimens – as such photography is a new tool changing entomology. Of course, most observations are made using only human senses without photographic or specimen documentation, but all observations can be subject to biases.

Observer biases are our evolutionary legacy. Our brains evolved to process and interpret data based on patterns observed in previously processed data. Because of the vast amount of data flowing in from our five senses and our limited ability to focus on data, our brains let most data be background. Even the subset of data that we focus our attention on is filtered, who hasn’t taken a photograph and found something much more interesting in the photograph than the original subject (e.g., these mites on harvestmen)? All data, even the data subset we are focused on can be misinterpreted. When teaching scientific methods, my students always enjoyed the optical illusion exercises to demonstrate why objective analyses and accurate measurement are important.

Remember, that the brain also compares incoming data to previous data. This allows pattern recognition. Recently, Ted and I were blacklighting along the Mississippi River in Southeast Missouri. We found a pair of Elaphidion mucronatum (spiny oak borer) a very common insect in Southeast Missouri. So common that many would move on to other more interesting subjects at that point. The insects were in a mate guarding situation.  Because I had a name for the behavior, my brain put my observation in the mate guarding category. At this point I would have moved on, except Ted wished to document the subject with his camera rig, which meant I would do what any friend should: watch the insects while Ted ran to vehicle to get his camera so he would be able to photograph them. While Ted was gone things got interesting. The male was positioned above the female, who was more or less caged between his legs. The pair was moving in unison on the tree trunk with very little actual contact between the pair. This was interesting, but when the female E. mucronatum suddenly shot out from under the male ending up 10’ vertical below him on the side of the tree trunk I was stunned. The male covered this distance with amazing speed and recaptured the female. After a couple minutes the female again shot out from under went down a few feet and doubled back ending out of sight above the male. At this point the male remained motionless for a brief period. When Ted came back with his camera, I took my eyes off of the male to tell him about what I had seen, and the male had vacated the area. Later, on the very same tree, we saw a mate guarding pair (presumably the same individuals) coming down towards us.

I have viewed many mate guarding insects. Mate guarding is a male insect using its body to prevent other males from mating with this female. Evolutionary biologists will explain mate guarding behavior in terms of enhanced male reproductive success, and that is why mate guarding persists. I never questioned this explanation, but should have. The E. mucronatum observation caused me to see mate guarding in a new way and realize that mate guarding involves a male and female component – I know this seems obvious, but I had my own cultural bias to overcome in this regard. I had never considered that mate guarding could involve non-willing females.

Based on a 10 minute observation of a very common insect my new understanding of mate guarding now recognizes that mate guarding influences female fitness also. Mate guarding persists when it creates a change in fitness in the male and female such that there is a positive net change in fitness for reproductive output for all individuals involved. In the case I witnessed, there may actually be a reproductive cost for the female and that is why she tried to avoid/escape the mate guarding. I have much more to learn about mate guarding.

Science is a way of objectively seeing the world and testing what you have seen to approach truth. This observation of E. mucronatum was also a mirror that showed my cultural bias and how that bias influenced my interpretation of my observations. For me, this observation could be a watershed event.

The moral(s) of this story:

  1. Life is short: enjoy time in the field with friends.
  2. Pay attention. There are new and wonderful things to observe even in the common and mundane.
  3. Be aware of the biases that can keep you from the truth.
  4. Have fun out there!

Copyright © Kent Fothergill 2013

“Blue-sky” tips and tricks

/ Ted C. MacRae / 4 Comments

For the past two years I’ve been working to refine my “blue-sky” technique for insect macrophotographs. This refers to careful balancing of camera and flash settings to achieve full-flash illumination of the subject while still allowing enough ambient illumination from the sky to produce a natural looking blue background. The use of flash, of course, is almost a necessity in insect macrophotography, as it’s nearly impossible to take hand-held photographs of insects, especially small ones, using only ambient light—there just isn’t enough of it to adequately illuminate the subject while using fast shutter speeds to prevent motion blur and high aperture settings to achieve acceptable depth-of-field. Flash illumination, however, has a drawback (actually several, but let’s focus on one)—if there isn’t something else close enough behind the subject to reflect light from the flash, the background will be jet black. In some cases this is perfectly fine, and it is almost always preferred over a cluttered background of jumbled branches and foliage. However, it usually doesn’t work well with darkly colored insects, and to me it gives the undesirable impression that the photo was taken at night. I suppose I could carry around colored cards to place behind the subjects that I photograph, but as a photographer who prides himself on the ability to take in situ field photographs of insects in their native habitats, something about the ‘artificiality’ of colored cards prevents me from resorting to them. A leaf placed behind the subject may be an acceptable alternative, but is usually possible only with quite small subjects (due to the size of the leaf needed) and is virtually impossible in dry, western habitats.

cf. Eremochrysa punctinervis | Gloss Mountains, Major Co., Oklahoma

cf. Eremochrysa punctinervis | Gloss Mountains, Major Co., Oklahoma

It’s hard to recommend specific camera settings for blue sky background, as they must be determined experimentally in each situation. The above photo of what I take to be Eremochrysa punctinervis (a green lacewing in the family Chrysopidae—identification via Frank & Slosser 1996) was taken with a 100mm macro lens set at f/16 and with ISO bumped up slightly to 320 (I normally use ISO 100–200) and shutter speed decreased slightly to 1/160 sec (I normally use 1/200 to 1/250 sec). The higher ISO makes the camera sensor more sensitive to light and the slower shutter speed allows more time for ambient light to reach the sensor. When aimed at the brightest part of the sky (next to but not right at the sun), these settings allowed sufficient light to register this beautiful shade of blue on the camera sensor. The ambient light alone is still not sufficient to illuminate the subject—if the photograph had been taken with these settings but without flash, the background would still be blue, but the subject and branch on which it is sitting would be nearly black! Only a flash pulse occurring while the shutter is open can provide enough light to fully illuminate the subject when the aperture setting is that high. In essence, the photo combines two exposures—a flash-illuminated subject and an ambient-illuminated sky.

Eremochrysa punctinervis | Gloss Mountains, Major Co., Oklahoma

Same photo before cloning out antennal shadowing

One problem that can be encountered when using this technique is the effect of wind. Holding the subject up against the sky exposes it to even the slightest of breezes, which can cause movement of delicate body parts such as the long antennae of this subject. What looks like blurring of the antennae is actually shading of the sky by the antennae as they fluttered in the wind. The antennae themselves were “frozen” by the very short flash pulse—much shorter than the 1/160 sec exposure, but they blocked enough light from the sky during the 1/160 sec exposure to darken the part of the background over which they moved. In the case of the finished photo shown at the beginning of the post, it was a relatively simple matter to use Photoshop’s cloning tool to remove the shadowing. Nevertheless, even more desirable is to avoid the need for such post-processing manipulations to begin with—waiting for a pause in the wind or moving to a more protected location would have obviated the need for PS cleanup.

REFERENCE:

Frank, W. A. & J. E. Slosser. 1996. An Illustrated Guide to the Predaceous Insects of the Northern Texas Rolling Plains. Texas Agricultural Experiment Station, Cotton DVD, Publication #MP-1718, 24 pp.

Copyright © Ted C. MacRae 2013

Cover photo for the June 2013 issue of The Coleopterists Bulletin

/ Ted C. MacRae / 4 Comments

Eurhinus cf. adonis on Solidago chilensis | Chaco Province, Argentina

Did anybody think that weevil photograph on the cover of the June 2013 issue of The Coleopterists Bulletin (vol. 67, no. 2) looked familiar? If so, it’s  because you saw it first in my April 28, 2013 post,  This is Eurhinus cf. adonis (ID courtesy of Charles O’Brien), which I photographed near La Escondida in Chaco Province, Argentina on flowers of Solidago chilensis. This photo reminds me that I need to pay more attention to portrait-style photographs, as landscape oriented photos don’t often fit very well on magazine and journal covers.

Beyond being my first cover for The Coleopterists Bulletin (and I hope not the last), the issue contains a number of papers that I will be studying with interest. These include a paper describing new species of Chrysobothris (Buprestidae) from the West Indies with notes on others, a checklist of longhorned beetles (Cerambycidae) from Montana, and the synonymization of Megacyllene comanchei under M. angulifera—all by Mike Ivie and colleagues (I did have the privilege of reviewing the Chrysobothris paper, and my Megacyllene “comanchei“—now M. angulifera—specimens were among those examined). Also of interest to me is a paper about wood-boring beetle emergence (including Buprestidae and Cerambycidae) from ponderosa pines killed by mountain pine beetle and fire in the Black Hills of South Dakota. Finally, Brett Ratcliffe has included a primer on best writing and curatorial practices for describing a new species of beetle—as a somewhat but not highly practiced alpha taxonomist, this should be an interesting read for me that will hopefully give me a chance to correct any nascent bad habits that I may be developing. Scarabaeologists and weevil specialists should be equally pleased with this issue, with a half-dozen or more papers in each group filling most of the remaining pages.

Copyright © Ted C. MacRae

Plionoma suturalis in Oklahoma—a new state record!

/ Ted C. MacRae / 11 Comments

When I returned from my vacation/insect collecting trip to western Oklahoma two weeks ago, most people upon learning where I went responded with a funny look that said, “Why would you want to go to Oklahoma?” Even entomologists familiar with my inclination for beetles merely assumed I went there to collect tiger beetles and were surprised to learn that, for this trip, I was actually targeting jewel beetles (family Buprestidae) and longhorned beetles (family Cerambycidae). Jewel beetles and longhorned beetles, of course, are largely associated with dead wood, and western Oklahoma is smack dab in the middle of the Great Plains. However, this does not mean that there are no trees in the area, or that whatever trees do exist are merely western examples of pedestrian eastern species with a depauperate beetle fauna. In fact, I came to this area precisely because previous visits had seemed to indicate high potential for interesting species of woodboring beetles. On my September 2011 visit, passing through on my way back from Colorado, I found several individuals of the unusual fall-active Acmaeodera macra (representing a northern range extension), and during last year’s fall visit I found a single Chrysobothris octocola adult on a dead mesquite (Prosopis glandulosa) branch—a northeastern range extension and new state record for Oklahoma! Interesting records for other species of beetles over the past few years also supported the idea that western Oklahoma was understudied and held the promise of more interesting new records for anyone willing to spend time in the area.

Plionoma suturalis (male) | Gloss Mountains, Major Co., Oklahoma

Plionoma suturalis (male) on mesquite (Prosopis glandulosa) | Gloss Mountains, Major Co., Oklahoma

Nearly all of these interesting records have been found in the Gloss Mountains, a fascinating system of gypsum capped, red clay mesas in Major Co. I now regard the Gloss Mountains State Park as my “portal” to northwestern Oklahoma and can’t imagine traveling to or through the area without stopping and spending time knocking around this fascinating, brick-red landscape. Such was the case during this year’s trip, and while I had decided to spend at least the first field day in and around the State Park, the collecting was so good that I stayed for a second day and returned for a third later in the week. The beetle shown in these photos is part (and only part) of the reason why. Arriving in the morning of the first day in the field, I headed straight for the mesquite tree on which I had found the C. octocola adult last fall. It’s a common species in the southwestern U.S. that normally wouldn’t warrant any special attention, but since the Oklahoma record was based on a single specimen I wanted to see if I could find additional individuals to confirm that the species was actually established in the area and that last year’s record wasn’t just a one-off. I whacked a dead branch, and onto my beating sheet fell a C. octocola adult! I whacked another dead branch, and off fell another adult! As it was, I would find the species as abundantly here, in strict association with mesquite, as I have seen it at other locations further to the southwest. Soon after collecting the first few C. octocola adults, however, I whacked a live branch on the same mesquite tree, and off fell two large, colorful longhorned beetles that I recognized instantly as representing the species Plionoma suturalis.

Plionoma suturalis (female) | Gloss Mountains, Major Co., Oklahoma

Plionoma suturalis (female) on mesquite flowers | Gloss Mountains, Major Co., Oklahoma

Plionoma suturalis belongs to the great tribe Trachyderini. Beetles in this tribe are known for the bright colors, attraction to flowers, and diurnal (day-active) tendencies, and while we have a few species in the eastern U.S. they are far more diverse in the southwestern states. Plionoma suturalis and another U.S. species (P. rubens) are known to occur from Texas west to California and south into northern Mexico, but I immediately had the feeling that finding this species in Oklahoma was a significant record. The beetles were abundant on the mesquite trees that lined the parking lot and dotted to landscape below the main mesa, with many observed feeding on the flowers (the trees were in full bloom) and numerous mating pairs also observed. Considering its abundance at the site and possible significance of the record, I collected several dozen specimens to serve as vouchers (not to mention I had only collected a handful of specimens in all of my previous years of collecting). Checking my database later that evening (I never leave home without my computer!) confirmed my suspicions—Oklahoma was not only a new state record, but a significant northeastern range extension. In fact, the closest previous record was by Lingafelter & Horner (1993), who recorded eight specimens from Wichita Co., Texas—just over 200 miles to the south! Further, the Wichita Co. specimens were all collected in 1956, and subsequent collecting had yielded no additional specimens, leading the authors to consider the status of this species in north-central Texas as doubtful.

The female feeds on flowers of mesquite (Prosopis glandulosa)

Large number of individuals were seen feeding on mesquite flowers.

Plionoma suturalis is one of only a handful of North American longhorned beetle species in which the adults exhibit bimodal seasonal activity, with adults appearing during the spring months, disappearing during the summer, and reappearing in the fall (see  for a previous example from Missouri) (Linsley 1962). In the Lower Rio Grande Valley of south Texas (where the activity of many species of longhorned beetles and other insects is distinctly bimodal to coincide with moderate temperatures and increased precipitation during spring and fall), this species has been found on fresh-cut mesquite and huisache (Acacia farnesiana) in the fall months and on the blossoms of fabaceous trees during spring and early summer (Hovore et al. 1987).

REFERENCES:

Hovore, F. T., R. L. Penrose & R. W. Neck. 1987. The Cerambycidae or longhorned beetles of Southern Texas: a faunal survey. Proceedings of the California Academy of Science 44(13):283–334, 20 figs.

Lingafelter, S. W. & N. V. Horner. 1993. The Cerambycidae of north-central Texas. The Coleopterists Bulletin 47(2):159–191, 7 figs.

Linsley, E. G. 1962. The Cerambycidae of North America. Part III. Taxonomy and classification of the subfamily Cerambycinae, tribes Opsimini through Megaderini. University of California Publicatons in Entomology 20:1–188, 56 figs.

Copyright © Ted C. MacRae 2013

A chalcidid jewel beetle parasitoid wasp

/ Ted C. MacRae / 9 Comments
Acanthochalcis nigricans | Gloss Mountains State Park, Major Co., Oklahoma

Acanthochalcis nigricans | Gloss Mountains State Park, Major Co., Oklahoma

As a student of jewel beetles with an interest in their larval host plant associations, rearing has been an important tool for my studies. Through the years, I’ve retrieved literally hundreds of batches of dead wood from the field and placed them in rearing containers that I keep in my garage. It’s hard work, but the several thousand jewel beetles that I’ve reared from these batches, many representing new distributions, host associations, and even new species (e.g., MacRae 2003) clearly suggest it has been worth the effort. Of course, jewel beetles are not the only insects that emerge from this wood. Numerous other insects have shown up in the rearing containers as well, mostly beetles in other families associated with dead wood such as longhorned beetles, powderpost beetles, checkered beetles, etc. Non-beetles have been reared as well, mostly representing parasitic hymenopterans, and in this group my favorite are the chalcidid wasps (family Chalcididae). Chalcidids and some of their close relatives are instantly recognizable by their greatly swollen and toothed hind femora. Most species in this family are parasitoids of Lepidoptera and Diptera, but some parasitize other insects, including jewel beetles and especially those in the genus Chrysobothris. I have reared a few hundred of these wasps over the years, representing at least a dozen or more species and currently being identified by fellow buprestophile Henry Hespenheide. Once identified, it will be an easy matter to associate these specimens with the Chrysobothris beetles that emerged with them from the same batch of wood. From this, we anticipate that any number of new parasitic wasp/beetle host associations will be revealed.

Among chalcidid wasps, the large size and very long ovipositor distinguish this genus.

Among chalcidid wasps, the large size and very long ovipositor distinguish this genus.

The chalcidid wasp featured in this post was not reared, but rather was encountered in the field during my recent collecting trip to northwestern Oklahoma. In fact, it was the very first insect that I encountered at the very first site that I stopped at—Gloss Mountains State Park. Although the wasp was photographed on a dead branch of eastern red-cedar (Juniperus virginiana), I first saw it on a dead branch of mesquite (Prosopis glandulosa). Based on its long ovipositor and large size (~19 mm in length, including the ovipositor), I presume this to be one of the two Acanthochalcis species commonly encountered in North America, with the presence of white pubescent patches on its abdomen identifying it as A. nigricans, occurring across the southwestern U.S. from Kansas and Oklahoma to California (A. unispinosa, ranging from Texas to California, lacks these pubescent patches). This species is a known associate of Chrysobothris jewel beetles, including C. femorata and C. edwardsii (Universal Chalcidoidea Database), but in this case I believe it is associated with C. octocola—an equally large jewel beetle that I first encountered on the mesquite at this very spot last fall (a new state record!). I beat quite a few more C. octocola adults from dead mesquite branches during this trip but didn’t find any other Chrysobothris spp. associated with the mesquite. That said, it is possible that the wasp is associated with the larger of two species of Chrysobothris that I beat from the eastern red-cedar at the site (forgive me for being coy about the identity of the beetle right now, as it will be the subject of a future post). However, since all of the wasps I saw that day were originally seen on or flying around dead mesquite branches I’m betting on C. octocola.

The white abdominal pubescent patches distinguish this species from A. unispinosa.

The white abdominal pubescent patches distinguish this species from A. unispinosa.

REFERENCE:

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.

Copyright © Ted C. MacRae 2013

Agrilus fuscipennis on Persimmon

/ Ted C. MacRae / 10 Comments

Agrilus fuscipennis

Agrilus fuscipennis may not be the largest or the prettiest member of the genus occurring in Missouri (that honor is reserved for Agrilus concinnus, or “hibiscus jewel beetle”—MacRae 2004). Nevertheless,  it comes pretty darned close! Add to that the fact that it is among our most seldom encountered jewel beetles, and you can understand how excited I was to see this species on my sheet after beating a small persimmon (Diospyros virginiana) tree last weekend at Hercules Glades Wilderness in the White River Hills of extreme southwestern Missouri. In fact, I have only collected this species three times previously—all single specimens beaten from persimmon, and all back in the 1980s!

Agrilus fuscipennis

Jewel beetles are unquestionably popular among insect collectors, due no doubt in large part to their vivid, metallic colors. I think the family, however, would be even more popular were it not for the genus Agrilus. Fully one in five species of jewel beetles belongs to this genus, which at nearly 3,000 described species and counting (Bellamy 2008) is perhaps the largest genus in the entire animal kingdom. As might be expected, such hyperdiversity has resulted in taxonomic quagmire, with species limits difficult to define and many hardly distinguishable except by examination of male genitalia (MacRae 2003). Additionally, in contrast to the rest of the family which is generally recognized as containing some of the most spectacularly beautiful beetles in the world, the most species of Agrilus are small, usually less than 8 mm in length and often as small as only 4–5 mm, and also lack the vivid colors (at least, to the naked eye) for which the rest of the family is so noted.

Agrilus fuscipennis

Agrilus fuscipennis is one of several species that buck this general Agrilus theme. While not forming a discrete taxonomic group within the genus, they are all unified by the following characteristics: 1) relatively large for the genus (A. fuscipennis measures 12–14 mm length), 2) vivid red pronotum and black elytra, and 3) mine the lower trunks, crown and main roots of living rather than dead host plants. For A. fuscipennis the larval host is persimmon, and other similar species include A. vittaticollis on serviceberry (Amelanchier) and A. concinnus on wild hibiscus (Hibiscus). These other species also are not very commonly encountered, at least in my experience, perhaps partly because they are not as easily reared from their hosts as species that develop as larvae in dead wood (the latter can be easily reared by retrieving infested wood from the field and placing in containers to trap emerging adults).

Agrilus fuscipennis

In the interest of full disclosure, these photos were taken in the studio after returning home. Although the persimmon branch is real, the “blue sky” is actually just a colored index card. I prefer to photograph insects in the field, especially with insects such as tiger beetles where it is desirable to include elements of the insect’s natural habitat in the photograph. However, I don’t have a problem with studio photography if field photographs prove too difficult or time-consuming or present too high a risk of escape by a prize specimen. My normal protocol for the latter is to place the first individual in a vial and continue to search for another that I will then try to photograph in the field. If that doesn’t work then I still have the first individual as a backup for studio photographs. In the case of this beetle, I found it on the very first clump of persimmon that I beat but never saw another despite beating persimmon for the rest of the afternoon (just like the three I found separately back in the 80s)! I have plans to photograph A. concinnus later this summer on its Hibiscus host plant in southeastern Missouri—hopefully I will succeed in getting true field photographs of that species.

Agrilus fuscipennis

REFERENCES:

Bellamy, C. L. 2008. World catalogue and bibliography of the jewel beetles (Coleoptera: Buprestoidea), Volume 4: Agrilinae: Agrilina through Trachyini. Pensoft Series Faunistica 79:1–722.

MacRae, T. C. 1991. The Buprestidae (Coleoptera) of Missouri.  Insecta Mundi 5(2):101–126.

MacRae, T. C. 2004. Beetle bits: Hunting the elusive “hibiscus jewel beetle”. Nature Notes, Journal of the Webster Groves Nature Study Society 76(5):4–5.

Copyright © Ted C. MacRae 2013