Arthropoda

Arthropods – insects, arachnids, crustaceans, myriapods, & relatives

Spring beetles on Coreopsis flowers

/ Ted C. MacRae / 3 Comments
Abby Lee, Ryan Fairbanks, Stephen Penn atop a rhyolite glades

The WGNSS Entomology Group takes in the view of rhyolite glades from atop Hughes Mountain.

Each spring the Entomology Group of the Webster Groves Nature Study Society takes a field trip to one of the many natural areas outside of the St. Louis area. This year the destination was Hughes Mountain Natural Area, about 75 miles SSW of St. Louis in Washington Co. I especially looked forward to going there this spring, as my last visit to the area was close to 20 years ago. Despite the long absence, I vividly recalled the spectacular vistas from atop the mountain of rhyolite and the diversity of unique plants and insects in the igneous glades that flanked its slopes. When we arrived, we found the glades ablaze with spring wildflowers in full bloom, the most prominent of which was lance-leaved coreopsis (Coreopsis lanceolata). As one of the so-called “yellow composites”, coreopsis is a favored source of pollen and nectar for a variety of insects, including beetles and especially the jewel beetles that I find so interesting.

Acmaeodera neglecta

Acmaeodera neglecta Fall, 1899

Species in the genus Acmaeodera are incredibly diverse in the southwestern U.S. (nearly half of the ~150 species/subspecies known from the U.S. occur in Arizona), where they are usually encountered on a variety of flowers. It is my opinion that the adult beetles mimic small bees, especially in flight by virtue of their fused elytra that do not separate during flight as in most other beetles and thus results in a profile resembling that of a small sweat bee (family Halictidae). The diversity of Acmaeodera drops off considerably in the eastern U.S., with only three species occurring broadly in the area. Missouri is a bit luckier than most eastern states, as two additional species found primarily in the south-central U.S. also occur here (MacRae 1991). One of these is Acmaeodera neglecta Fall, 1899. This tiny species (adults measure only 4–6 mm in length) is very similar to the much more common and widespread A. tubulus (Fabricius, 1801) (see photos here), and in fact its resemblance to that species is so great that it remained unreported from Missouri until Nelson (1987) recognized it among material that I had collected and sent to him during my early collecting days. Acmaeodera neglecta can be distinguished from A. tubulus by the elytra with slightly larger punctures and duller surface and the spots usually longitudinally coalesced into an irregular “C”-shaped marking on each side. I find this species most often in glade habitats.

Acmaeodera ornata

Acmaeodera ornata (Fabricius, 1775)

Acmaeodera ornata (Fabricius, 1775) is more widespread than A. neglecta (although not nearly so commonly encountered as A. tubulus). This handsome species is distinctly larger than A. tubulus and A. neglecta, usually around 8-11 mm in length, and has a broader, more flattened appearance with a distinct triangular depression on the pronotum. The elytra have a bluish cast rather than the bronzy sheen of A. tubulus and A. neglecta, and the spots on the elytra are smaller, more numerous, and more of a creamy rather than yellow color. No other species in the eastern U.S. can be confused with it, although there is a very similar species (A. ornatoides Barr, 1972) that occurs in Oklahoma and Texas. I have encountered this species numerous times on a variety of flowers in Missouri but have never managed to rear it, and in fact larval hosts remain unknown with the exception of one very old (and unreliable) report of the species breeding in hickory (Carya) and black-locust (Robinia).

Valgus canaliculatus

Valgus canaliculatus (Olivier, 1789)

As a general rule, beetles in the family Scarabaeidae don’t visit flowers—species in the subfamily Cetoniinae being a significant exception. This tiny representative of the subfamily, Valgus canaliculatus (Olivier, 1789), is no larger than the Acmaeodera neglecta adult above by length, although the body is broader and strongly flattened. This species is a representative of the tribe Valgini, one of only two tribes in the family that possess dorsal and ventral scale-like setae (the unrelated tribe Hopliini, or monkey beetles, being the other) (Jameson & Swoboda 2005). It has been suggested that the setae might play a role in crysis or adaptive coloration, and even more interesting is the association of most New World species with termites. Eggs are laid in termite galleries and the larvae feed on the wood within the galleries, but it remains unclear whether the termophily is obligatory or the beetles are simply taking advantage of the stable environment and accessible food source offered by termite colonies. Like other species in the subfamily, the adults are fond of flowers; however, only male valgines visit flowers, using specially modified, brush-like mouthparts to lap up nectar. As far as has been determined, the males do not feed on pollen.

Valgus canaliculatus

Note the flattened, scale-like setae covering both the dorsal and ventral surfaces as well as the legs.

REFERENCES:

Fall, H. C.  1899. Synonpsis of the species of Acmaeodera of America, north of Mexico. Journal of the New York Entomological Society 7(1):1–37 [pdf].

Jameson, M. L. & K. A. Swoboda. 2005. Synopsis of scarab beetle tribe Valgini (Coleoptera: Scarabaeidae: Cetoniinae) in the New World. Annals of the Entomological Society of America 98(5):658–672 [pdf].

MacRae, T. C. 1991. The Buprestidae (Coleoptera) of Missouri. Insecta Mundi5(2):101–126 [pdf].

Nelson, G. H. 1987. Additional notes on the biology and distribution of Buprestidae (Coleoptera) in North America, II.   The Coleopterists Bulletin 41(1):57–65 [pdf].

© Ted C. MacRae 2015

A cicada that snaps, crackles, and pops!

/ Ted C. MacRae / 3 Comments

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

Platypedia putnami

Platypedia putnami | Las Animas Co., Colorado

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

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

REFERENCES:

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

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

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

© Ted C. MacRae 2015

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

/ Ted C. MacRae / 6 Comments
American carrion beetles (Necrophila americana) aggregating at sap flow on the trunk of an oak (Quercus sp.) tree.

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

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

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

Necrophila americana mating pair.

Necrophila americana mating pair.

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

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

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

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

REFERENCES:

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

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

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

© Ted C. MacRae 2015

Multiple Megarhyssa males

/ Ted C. MacRae / 9 Comments

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

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

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

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

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

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

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

REFERENCE:

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

© Ted C. MacRae 2015

Cover Photo—The Coleopterists Bulletin 69(1)

/ Ted C. MacRae / 3 Comments

cso69-1co14.indd

The March 2015 issue of The Coleopterists Bulletin (vol. 69, no. 1) is out now (I got mine yesterday), and while I’m always happy to see the latest issue of this journal in my mailbox I am especially pleased with this one because it features my photograph of an adult female Crossidius coralinus fulgidus on flowers of gray rabbitbrush (Ericameria nauseosa). I photographed this beetle in September 2011 near Vernal, Utah at the beginning of a trip with Jeff Huether to find and photograph endemic sand dune tiger beetles across the western U.S. We had just visited the dunes near Maybell, Colorado and were on our way to Idaho to visit the St. Anthony and Bruneau Sand Dune systems before dropping south to Coral Pink Sand Dunes in Utah and the Great Sand Dunes in Colorado. I was still a “Crossidius virgin” at that point—my first real Crossidius collecting trip would not come until two years later when Jeff and I visited the Great Basin and surrounding areas in a dedicated effort to find as many species/subspecies of Crossidius as possible (we succeeded in finding 12 of 14 targeted taxa). Having never seen C. coralinus before, you can imagine my excitement at seeing the spectacularly colored adults sitting atop flowers of their rabbitbrush host plants. I am especially fond of this photo, however, because it actually represents one of my earliest attempts to combine a natural blue sky background with a flash-illuminated subject—a technique I had learned from John Abbott just a few weeks earlier at the inaugural BugShot Workshop in Gray Summit, Missouri (just 15 miles from my home). I didn’t quite get the shade of blue I was looking for in this particular shot, but it’s close enough and the subject depth-of-field couldn’t be better. I have worked a lot on this technique since then and now consider blue sky background as part of my signature style.

This is the third issue of The Coleopterists Bulletin to feature one of my photographs on the cover. The first was the June 2013 issue (vol. 67, no. 2), which featured a beautiful, metallic green weevil, Eurhinus cf. adonis (2nd photo) that I photographed on flowers of Chilean goldenrod (Solidago chilensis) in northern Argentina, and the very next issue (September 2013, vol. 67, no. 3) featured my photograph of Chrysobothris octocola on dead mesquite (Prosopis glandulosa) in western Oklahoma (and a new state record).

If you’re not one already, consider becoming a member of The Coleopterists Society (I’ve been one for 33 years now!). Their flagship journal, The Coleopterists Bulletin, is your one-stop shop for all things beetley—a quarterly fix of pure elytral ecstacy! In addition to the latest issues of the journal, your membership also gives you online access to archives of past issues via JSTOR and BioOne.

© Ted C. MacRae

Buprestidae type specimens at Fundación Miguel Lillo, Argentina

/ Ted C. MacRae / 1 Comment

During my most recent visit to Argentina this past February and March, I had the chance to go behind the scenes and visit the entomology collection at Fundación Miguel Lillo, Instituto de Entomología, Tucumán. It’s always a treat to visit any entomology collection—public or private—at any location. When the collection has holdings of Buprestidae, so much the better. Much to my delight, however, this collection not only had holdings of Buprestidae (not surprisingly representing primarily Argentine species), but also a small collection of type specimens designated by Antonio Cobos Sanchez (1922–1998). Cobos was one of the 20th century’s most prolific students of Buprestidae, with publications in the family spanning the period from 1949–1990 (coincidentally, 1990 being the year of my very first buprestid publication!). I was graciously allowed to photograph these specimens, some of which present interesting nomenclatural situations that are worthy of comment. These are presented below with my notes.

Jose xx & Ted MacRae

Looking at the insect collection at Fundación Miguel Lillo, Argentina.

Sufamily POLYCESTINAE

Tribe TYNDARINI

Tylauchenia golbachi Cobos, 1993 (currently placed in Oocypetes)

Tylauchenia golbachi Cobos, 1993. The species was moved to the genus Ocypetes.

Lapsus calami or mislabeled type specimen? Cobos (1973) described Tylauchenia golbachi from Argentina (now placed in the genus Ocypetes), stating the type locality as “6 kms. N. de Belén, 1.240 m. alt., Catamarca, Argentina (Willink, Terán y Stange coll., con trampa de Malaise, 1-15-I-1970…)”. The specimen above bears the holotype label, but the locality label clearly shows that it was collected in Tucumán rather than Catamarca and that the collector’s name is Guanuco rather than the above stated names. Interestingly, in the same publication Cobos gives the allotype female collection data as “San Pedro de Colalao, Tucumán, Argentina (Coll. Guanuco, 9-III-1949)”. At first I thought this might actually be the allotype rather than the holotype; however, 1) the specimen clearly bears a holotype label, and 2) it is also clearly a male based on the dissected genitalia preserved on the label below the specimen. There are two possible explanations, both of which make it difficult to determine what is the true type locality: 1) the holotype and allotype specimens are correctly labeled, but Cobos simply transposed their label data in his publication describing the species, making Tucumán the true type locality, or 2) the holotype and allotype locality labels were switched at some point and the true type locality is Catamarca, as stated in the publication in which the species is described. This latter possibility is more serious, as in addition to the doubts it generates regarding the type locality it also raises concern about the integrity of the holotype specimen. The latter explanation, however, seems less likely, as it is more difficult to imagine a scenario where only the locality label but not the others was switched than to imagine a transposition of label data in the publication. Sadly, at this point, there seems no easy way to determine which of the two explanations is correct.

Subfamily CHRYSOCHROINAE

Tribe DICERCINI

Lampetis tucumana monrosi Cobos (nomen nudum?)

Lampetis tucumana “monrosi” Cobos (ms name?)

A manuscript name? Cobos never actually proposed a subspecies “monrosi” for Lampetis tucumana (Guérin-Méneville & Percheron, 1835) (the name on the separate box label is misspelled). He did use the name for two other buprestid taxa: Tetragonoschema monrosi Cobos, 1949—now regarded as a synonym of T. argentiniense (Obenberger, 1915), and Anthaxia monrosi Cobos, 1972—now placed in the genus Agrilaxia. The holotype label on the specimen clearly states “Lampetis tucumana monrosi” in Cobos’ handwriting, so one can only presume that Cobos had identified this specimen as representing a distinct subspecies but never followed through and actually described it.

Ectinogonia (Pseudolampetis) fasciata metallica Cobos, 1969

Psiloptera (Pseudolampetis) fasciata metallica Cobos, 1969. Pseudolampetis was later considered a subgenus of Ectinogonia but is now regarded as a full genus.

Oh, what a tangled web we weave! Cobos (1969) originally described this taxon as a subspecies of Psiloptera (Pseudolampetis) fasciata Kerremans, 1919. Moore (1986) moved Pseudolampetis to a subgenus of Ectinogonia, which resulted in two taxa in the latter genus bearing the name “metallica“—Ectinogonia (Pseudolampetis) fasciata metallica (Cobos, 1969) and Ectinogonia metallica Fairmaire, 1856—the latter now considered a synonym of E. speciosa (Germain, 1856). In taxonomic nomenclature, two taxa in the same genus cannot bear the same name—a situation known as homonymy. In such cases, the older name has priority and the younger name, in this case Cobos’, must be replaced. This was done by Bellamy (2006), who proposed the new name moorei for this subspecies, resulting in the name Ectinogonia (Pseudolampetis) fasciata moorei Bellamy, 2006. To bring some level of absurdity to the situation, the subgenus Pseudolampetis was subsequently raised to full genus rank, being listed as such in the recent world catalogue (Bellamy 2008), and since Cobos’ name was not originally proposed within the genus Ectinogonia it no longer competes with Germain’s name in that genus. As a result, there is no homonymy and Cobos’ original name must once again stand as Pseudolampetis fasciata metallica (Cobos, 1969), while Bellamy’s replacement name must be regarded as unnecessary. This fact seems to have been overlooked when Pseudolampetis was raised to genus rank, as Cobos’ taxon is still listed in the world catalogue as “Pseudolampetis fasciata moorei (Bellamy, 2006)”! This situation is a perfect example of just how complicated these situations can be to identify, track, and update. The type locality for the unique female is given as “Chagual, 1.200 metros de altitud, Rio Marañón, en el Perú, VIII-1953 (B. Fernández leg.)”.

Subfamily BUPRESTINAE

Tribe STIGMODERINI

Conognatha rufiventris weyrauchi Cobos, 1969

Conognatha rufiventris weyrauchi Cobos, 1969. The taxon is now considered a synonym of Conognatha abdominalis Waterhouse, 1912.

Insufficient grounds. Cobos (1969) regarded this specimen from Peru as subspecifically distinct from Conognatha rufiventris Waterhouse, 1912 from Brazil based on a suite of subtle character differences and named the taxon Conognatha rufiventris weyrauchi in honor of Prof. W. Weyrauch, who made made the holotype specimen available to him for study. Moore & Lander (2010) considered that the taxon did not represent C. rufiventris, but rather was a uniquely colored specimen of Conognatha abdominalis Waterhouse, 1912. The holotype is a male with the type locality given as “del Valle de Chatichamayo, a 1.200 m., en Peru (J. Schuiike leg.)”.

Conognatha amphititres Cobos, 1958 (syn. of Buprestis amoena Kirby, 1818; currently placed in Conognatha)

Conognatha amoena amphititres Cobos, 1958. The taxon is now considered a synonym of C. amoena (Kirby, 1818).

Insufficient grounds—part II. Cobos (1958) regarded this specimen from Brazil as subspecifically distinct from C. amoena (Kirby, 1818—originally described in the genus Buprestis) based on subtle characters and gave it the name Conognatha amoena amphititres (no etymology was given for the subspecies name). Moore & Lander (2006) regarded these differences as insufficient for subspecies status and placed the taxon as a synonym of the parent species. The holotype is thought to be a female with the type locality given as “Rio de Janeiro (Brasil)”.

Tribe CHRYSOBOTHRINI

Colobogaster weyrauchi Cobos, 1966

Colobogaster weyrauchi Cobos, 1966

Cobos (1966) described Colobogaster weyrauchi from Peru and named it after the collector, relating it to the widespread Colobogaster cyanitarsis Gory & Laporte, 1837. The type locality was given as “Pucallpá, 200 m. alt., Perú (W. Weyrauch coll. I-1948)”.

Subfamily AGRILINAE

Tribe CORAEBINI

Dismorpha grandis Cobos, 1990

Dismorpha grandis Cobos, 1990

Cobos (1990) described Dismorpha grandis from Argentina in his very last buprestid publication, stating that the species had the appearance of an enormous D. irrorata (Gory & Laporte, 1839) (thus, the name “grandis“). The holotype is a male with the type locality given as “Bemberg, Misiones, Argentina (Exp. Hayward-Willink-Golbach: 12-29-I-1945)”.

Tribe AGRILINI

Diadorina golbachi Cobos, 1974 (monotypic)

Diadorina golbachi Cobos, 1974 (monotypic)

Cobos (1974) described Diadorina golbachi from Argentina as the only member (and thus the type species) of the new genus Diadorina (the genus is still regarded as monotypic), naming it in honor of the collector. The holotype specimen is a female with the type locality given as “La Tigres, Santiago del Estero, Argentina (R. Golbaeh coll. 11-16-1-1970)”.

Tribe TRACHEINI

Pachyshelus huallaga Cobos 1969 (correct spelling is huallagus)

Pachyshelus huallaga Cobos, 1969

Cobos (1969) described and named this species after the river at the type locality in Peru. He related it to Pachyschelus atratus Kerremans, 1896 from Brazil and northern Argentina, stating that it differed by its distinct and less brilliant coloration and other features. Since the genus name is considered masculine, the correct species name is “Pachyschelus huallagus Cobos, 1969″. The unique holotype is a female with the type locality given as “Tingo María, Rio Huallaga, 700 metros de altitud, Peru, X-1946 (W. Weyrauch leg.)”.

Pachyschelus weyrauchi Cobos, 1959

Pachyschelus weyrauchi Cobos, 1969

Cobos (1969) described Pachyschelus weyrauchi from Ecuador and named it in honor of its collector. He related the unique male to Pachyschelus aeneicollis (Kirsch, 1873) from Peru and Bolivia, citing differences in coloration, body shape, and surface sculpture. The type locality was given as “El Puyo, 900 metros de altitud, Ecuador, 10-IV-1958 (W. Weyrauch leg.)”.

There are two additional Buprestidae type specimens in the collection (Colobogaster pizarroi Cobos, 1966 and Hylaeogena cognathoides Cobos, 1969), but they are in another drawer that we did not find immediately and, thus, I did not have a chance to photograph them. My apologies!

REFERENCES:

Bellamy, C. L. 2006. Nomenclatural notes and corrections in Buprestidae (Coleoptera). The Pan-Pacific Entomologist 81(3/4):145–158 [pdf].

Bellamy, C. L. 2008. A World Catalogue and Bibliography of the Jewel Beetles (Coleoptera: Buprestoidea). Volume 2: Chrysochroinae: Sphenopterini through Buprestinae: Stigmoderini. Pensoft Series Faunistica No. 77, pp. 626–1260, Pensoft Publishers, Sofia-Moscow [details & links].

Cobos, A. 1966. Notas sobre Bupréstidos neotropicales. XV: Tres especies nuevas de Colobogaster Sol. (Coleoptera). EOS, Revista Española de Entomología 41(2-3):205–214 [pdf].

Cobos, A. 1969. Notas sobre Bupréstidos neotropicales XVII. Especies y subespecies nuevas (Coleoptera). EOS, Revista Española de Entomología 44(1968):19–43 [pdf].

Cobos, A. 1958. Tercera nota sobre Bupréstidos (Ins. Coleoptera) neotropicales descripciónes y rectificaciónes diversas. Acta Zoologica Lilloana 15:83–102 [pdf].

Cobos, A. 1973. Revisión del género Tylauchenia Burm., y afines (Coleoptera, Buprestidae). Archivos del Instituto de Aclimatacion 18:147–173 [pdf].

Cobos, A. 1974. Notas sobre Bupréstidos neotropicales, XIX. El género Amorphosternus H. Deyrolle y afines. Archivos de Instituto de Aclimatación 19:65–81 [pdf].

Cobos, A. 1990. Revisión del género Dismorpha Gistel (Coleoptera, Buprestidae). Revista Brasileira de Entomología 34(3):539–559 [pdf].

Moore Rodriguez, T. 1986. Contribución al conocimiento de los Buprestidos neotropicales (Coleoptera: Buprestidae). Revista Chilena de Entomología 13:21–29 [BioStor].

Moore Rodriguez, T. & T. Lander. 2010. Revision du genre Conognatha. Edition Magellanes 24:1–172 [introduction and generic discussion in French and Spanish; keys to species in English, French and Spanish] [order information].

© Ted C. MacRae 2015

Flower ants? Check again!

/ Ted C. MacRae / 21 Comments

Last spring while hiking the North Fork Section of the Ozark Trail in southern Missouri (Howell Co.), I made sure to check the abundant flowering dogwood (Cornus florida) blossoms that were in gorgeous peak bloom at the time (early May). I’ve learned to check flowers of dogwood whenever I can, as they are quite attractive to a variety of insects but especially those groups of longhorned beetles (family Cerambycidae) that tend to frequent flowers as adults. In the case of flowering dogwood, most of the cerambycids that I encounter belong to two genera: Molorchus and Euderces. Both of these genera are known for their great resemblance to small ants, no doubt representing examples of Batesian mimicry (where a harmless species adopts the appearance or warning signals of a harmful species to gain protection from predators).

Tilloclytus geminatus

Tilloclytus geminatus on Cornus florida | North Fork Section, Ozark Trail, Howell Co., Missouri

During this particular hike I was determined to photograph Molorchus bimaculatus, common in Missouri during early spring on a great variety of flowering trees. On this day, however, the tiny (<10 mm length) beetles were rather scarce, and I had been frustrated in my attempts to get good photographs of the few that I had found. I’ve seen enough of these beetles over the years that I can recognize them quickly for what they are without the need to closely examine every “ant” that I see. So when I saw an “ant” that was too big and convex in profile to be Molorchus I almost discounted it as a true ant. Something about it, however, gave me pause, and when I looked closer I saw that it was, indeed, a longhorned beetle. But, it was not Molorchus, nor was it Euderces. Instead, it was the species Tilloclytus geminatus—an exciting find!

Tilloclytus geminatus

Adults in profile greatly resemble ants of the same size.

Tilloclytus geminatus has been recorded only sporadically from across the eastern U.S., where it has been reared from a variety of deciduous hardwoods (Craighead 1923, Rice et al. 1985). Perry (1975) did report rearing this species from Pinus virginiana (along with several other species normally associated with hardwoods); however, that record likely represents an ‘‘overflow’’ host (Hespenheide 1969) that is not typical of the species’ normal host preferences. I myself had never seen the species until the years after I published my checklist of Missouri cerambycids (MacRae 1994), having succeeded in rearing adults from a variety of previously unrecorded hardwood hosts that I collected at several localities across southern Missouri (MacRae & Rice 2007). It remains, for me, an infrequently encountered species—perhaps part of this a result of being overlooked due to its effective ant mimicry.

Tilloclytus geminatus

The anterior, oblique markings give the illusion of a constricted “waist”, while the posterior, transverse markings resemble the “sheen” of a shiny abdomen.

Unlike Molorchus and Euderces, this species has not been frequently associated with flowers as adults. In fact, the only report I am aware of is that of Rice et al. (1985), who reported adults on flowers of hawthorn (Crataegus sp.). Perhaps this additional find on Cornus is indicative of a true adult attraction to flowers by T. geminatus, although a single adult provides only weak support. However, a related ant-mimicking longhorned beetle—Cyrtophorus verrucosus—has been collected on flowers of roughleaf dogwood (Cornus drummondii) (MacRae 1994) as well as flowering dogwood (Scheifer 1998a). The floral attraction of ant-mimicking cerambycids may be more characteristic of species in the subfamily Cerambycinae, as only one flower record exists (Physocarpus opulifolius) for Psenocerus supernotatus (Wheeler & Hoebeke 1985) and none exist for Cyrtinus pygmaeus, both in the subfamily Lamiinae rather than Cerambycinae and the only other true ant-mimicking species in Missouri of which I am aware.

REFERENCES:

Craighead, F. C. 1923. North American cerambycid larvae. A classification and the biology of North American cerambycid larvae. Dominion of Canada, Department of Agriculture, Technical Bulletin No. 27 (new series), 239 pp. [Internet Archive].

Hespenheide, H. A. 1969. Larval feeding site of species of Agrilus (Coleoptera) using
a common host. Oikos 20:558–561 [JSTOR].

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

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

Perry, R. H. 1975. Notes on the long-horned beetles of Virginia, part III (Coleoptera: Cerambycidae). The Coleopterists Bulletin 29(1):59 [JSTOR].

Rice, M. E., R. H. Turnbow Jr. & F. T. Hovore. 1985. Biological and distributional observations on Cerambycidae from the southwestern United States (Coleoptera). The Coleopterists Bulletin 39(1):18–24 [pdf].

Schiefer, T. L. 1998a. A preliminary list of the Cerambycidae and Disteniidae (Coleoptera) of Mississippi. Transactions of the American Entomological Society 124(2):113–131 [JSTOR].

Wheeler, A. G., Jr. & E. R. Hoebeke. 1985. The insect fauna of ninebark, Physocarpus opulifolius (Rosaceae). Proceedings of the Entomological Society of Washington 87(2):356–370 [BioStor].

© Ted C. MacRae 2015

Just how widespread is Prionus heroicus?

/ Ted C. MacRae / 29 Comments

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

Prionus heroicus male

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

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

Prionus heroicus male

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

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

Prionus heroicus male

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

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

Prionus heroicus male

Defensive posturing as a result of being disturbed.

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

Prionus heroicus male

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

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

REFERENCES:

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

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

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

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

Linsley, E. G. 1962. The Cerambycidae of North America. Part II. Taxonomy and classification of the Parandrinae, Prioninae, Spndylinae, and Aseminae. University of California Publications in Entomology 19:1–102, 1 plate [OCLC WorldCat].

Linsely, E. G., J. N. Knull & M. Statham. 1961. A List of Cerambycidae from the Chiricahua Mountain area, Cochise County, Arizona (Coleoptera). American Museum Novitates 2050:1–34 [pdf].

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

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

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

© Ted C. MacRae 2015