immatures

2019 Arkansas/Oklahoma Insect Collecting Trip iReport

/ Ted C. MacRae / 11 Comments

Alternative title: Rich and Ted’s Excellent Adventure

This is the seventh “Collecting Trip iReport”; this one covering a 5-day trip to Arkansas and Oklahoma from June 7–11, 2019 with my friend and local collecting buddy Richard Thoma. As with all previous “iReports” in this series, this one too is illustrated exclusively with iPhone photographs.

Previous iReports include the following
– 2013 Oklahoma
– 2013 Great Basin
– 2014 Great Plains
– 2015 Texas
– 2018 New Mexico/Texas
– 2018 Arizona

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…and so it begins!

Day 1 – Ozark National Forest, vic. Calico Rock, Arkansas
It’s been many years since I’ve visited these sandstone glades overlooking the White River near Calico Rock. Conditions were partly sunny when we arrived, but water on the ground suggested rain earlier in the day. We had only a short time to start exploring before the wind started blowing up and the smell of rain filled the air. I did manage to beat one Amniscus sexguttata from a branch of living Pinus echinata and collect a couple of Strigoderma sp. from Coreopsis lanceolata flowers before steady rain forced us to retreat.

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White River near Calico Rock, Arkansas—before the rain.
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White River near Calico Rock, Arkansas—rain’s a comin’!

Day 2 – Ouachita National Forest, Winding Stair Campground & Ouachita Trail, Oklahoma
We walked the trail from the campground S about 2½ miles and back. I started off with Acmaeodera tubulus on Krigia sp. flowers, eventually finding a lot of them on this plant at higher elevations along with a single Acmaeodera ornata, and I beat a few Agrilus cepahlicus off of Cornus drummondii. This had me thinking it would be a good buprestid day, but it wasn’t, the only other species collected being some Chrysobothris cribraria off of small dead Pinus echinata saplings and Pachyschelus laevigatus on Desmodium sp. Also beat a few miscellaneous insects off of Cercis canadensis and Vaccineum arborea and swept some from grasses and other herbaceous plants. Back at the campground I collected Chrysobothris dentipes on the sunny trunks of large, live Pinus echinata trees.

Emerald Vista, along the Talihema Scenic Drive.
Acmaeodera tubulus on flower of Rosa carolina.
Acmaeodera tubulus on flower of Rosa carolina.
Canthon sp.
Apheloria virginiensis reducta (ID by Derek Hennen).
The biggest cairn I’ve ever seen.

Ouachita National Forest, Talimena Scenic Dr at Big Cedar Vista, Oklahoma
There were lots of native wildflowers like Coreopsis tinctoria and Ratibida columnifera in bloom, so we stopped to check them out. There were lots of butterflies, however, I found only a single Typocerus zebra on Coreopsis lanceolata.

View south from Talimena Scenic Drive at Big Cedar Vista.
Coreopsis tinctoria (plains coreopsis).
Ratibida columnifera (upright prairie coneflower).

Ouachita National Forest, Winding Stair Campground, Oklahoma
We returned to the campground in the evening to do some blacklighting. I had high hopes, but only five cerambycids came to the lights, all represented by a single individual: Monochamus carolinensis, Acanthocinus obsoletus, Amniscus sexguttatus, Eutrichillus biguttatus, and Leptostylus tranversus (the first four are pine-associates). I also picked up a few other miscellaneous insects.

Rich processes the day’s catch as the blacklight hums in the background.

Day 3 – Medicine Park Primitive Campground, Oklahoma
There wasn’t much insect activity going on in eastern Oklahoma, so we drove out west to the Wichita Mountains for hopefully better luck. We found a small park with a primitive campground in the city of Medicine Park—my first thought was to beat the post oaks dotting the campground, but when I went into the native prairie between the campground and the creek I never came out! Right away I found what must be Acmaeodera ornatoides on flowers of Opuntia sp., then I found more on flowers of Gallardia pulchella along with Acmaeodera mixta. The latter were also on flowers of Thelesperma filifolium along with Acmaeodera neglecta—took a nice series of each, and I also got a few of the latter on flowers of Coreopsis grandiflora. Strangalia sexnotata were on flowers of C. tinctoria and Torilis arvensis, and then on the latter plant I saw a male Strangalia virilis—a Texas/Oklahoma specialty that I’ve never collected before! I spent the next hour looking for these guys and ended up with 3 males and 2 females along with a few Trichiotinus texanus—another Texas/Oklahoma specialty—and a single Agrilaxia sp. nr. flavimana (could be A. texana). One single Typocerus octonotatus was on flowers of Achillea millefolium. I think we may come back here tomorrow—I’d like to look for more S. virilis and beat the post oaks (the reason we stopped here to begin with).

A cacophony of native wildflowers!
An orgy of Euphoria kernii (Kern’s flower scarab) in Opuntia sp. flower. Multiple color forms exist for this species.
At first I thought this was a type of hover fly (family Syrphidae), but eventually I determined it to be Esenbeckia incisuralis, a horse fly (family Tabanidae)—incredible emerald green eyes!
Papilio polyxenes asterius (black swallowtail) caterpillar.
Echinocereus reichenbachii baileyi (lace hedgehog cactus).

Lake Lawtonka nr. Ma Ballou Point, Oklahoma
We stumbled into this area while looking for stands of Sapindus drummondii (soapberry)—found a small stand along the road, but it was too inaccessible. The same diversity of blooms were present as at the previous spot, so I picked a few longhorns off flowers of Coreopsis grandiflora and Gaillardia pulchella. Super windy, so we didn’t stay long.

View across Lake Lawtonka from Ma Ballou Point.
Neochlamisus sp. (case-bearing leaf beetle) larvae inside their “casas de caca” on Monarda fistulosa (bee balm).
I believe this is Harrisina coracina, a leaf skeletonizer in the family Zygaenidae. Both BugGuide and the Moth Photographers Group show records only from Texas.

Day 4 – Wichita Mountains National Wildlife Refuge, Oklahoma
Before starting the day’s collecting, we wanted to go into the Wichita Mountains National Wildlife Refuge to have a look around. On the way into the refuge we some American bison near the road and had to stop, take photos, and simply admire these massive, majestic beasts. We then went to the Cedar Plantation, where I had visited before back in 2012 and photographed black individuals of Cicindelidia obsoleta vulturina (prairie tiger beetle). No tiger beetles were out now (they come out in the fall), but I’d hoped to maybe see Cylindera celeripes (swift tiger beetle) along the 2-tracks in the area. No such luck—nevertheless, we saw a myriad of interesting insects, including several more Esenbeckia incisuralis (green-eyed horse flies) and a beautiful Trichodes bibalteatus (checkered beetle), the latter of which I photographed on flowers of Ratibida columnifera and Achillea millefolium with the big camera. Afterwards we visited the “prairie dog town” and got marvelous views and photographs of black-tailed prairie dogs.

Native American wildlife on a native American landscape.
American bison (Bison bison bison).
Wichita Mountains from Cedar Plantation.
Acmaeodera mixta on flower of Rudbeckia hirta (black-eyed Susan).
Typocerus octonotatus on inflorescence of Achillea millefolium (yarrow).
Strangalia sexnotatus on flower of Ratibida pinnata (gray coneflower)
Trichodes bibalteatus on flower of Rudbeckia hirta (black-eyed Susan).
Trichodes bibalteatus on flower of Ratibida pinnata (gray coneflower)
The author walks a bison trail through the Cedar Plantation.
Black-tailed prairie dog at its burrow entrance.
“Watch you lookin’ at, Willis?!”
Black-tailed prairie dog (Cynomys ludovicianus).

Medicine Park, Jack Laughter Park, Oklahoma
We’d noticed this spot yesterday because of the old post oaks and wealth of wildflowers blooming up the mountainside. There wasn’t much going on today, however—just a few Acmaeodera mixta on flowers of Gaillardia pulchella. I did find an Anthaxia (Haplanthaxia) sp. on my arm! Otherwise I spent some time photographing the landscape and some geometrid larvae on flowers of Gaillardia pulchella.

Opuntia sp. (prickly-pear cactus) amidst rocky exposures.
Small Oncoptus fasciatus (large milkweed bugs) nymphs colonize seed pods of Asclepias asperula (antelope-horns).

Medicine Park Primitive Campground, Oklahoma
We returned to this spot since we had so much luck yesterday. I was hoping to collect more Acmaeodera ornatoides and Strangalia virilis, but there was much less going on today than yesterday—basically didn’t see anything for the first hour and a half. I didn’t give up, however, and kept checking the area where we saw most of the S. virilis yesterday, and eventually I saw another male in the same area as yesterday on the same stand of Torilis arvensis. I found two more males in the same area over the next hour, so three males on the day was a good reward for the time spent looking for them. I also collected Trichodes apivorus and Trichiotinus texanus on flowers of Allium sp. Interestingly, beating the post oaks—the reason why I originally wanted to stop here—produced nothing. So, not very many specimens on the day, but happy with those I did get.

Thelesperma filifolium (stiff greenthread).
Coreopsis grandiflora (large-flowered tickseed).
Gaillardia pulchella (firewheel).
Coreopsis tinctoria (plains coreopsis).
Torilis arvensis (erect hedge parsley), introduced.
Opuntia sp. (prickly-pear cactus).
Opuntia sp. (prickly-pear cactus).
Allium sp. (wild onion).

Medicine Park, Jack Laughter Park, Oklahoma
I was pretty much done for the day after spending all morning at the refuge and most of the afternoon at the previous spot, but Rich wanted to take another look at Jack Laughter Park because he’d found some interesting grasshoppers there. As with earlier in the day there were few beetles of interest to me, but I did collect a couple of Trichiotinus texanus on flowers of Cirsium undulatum. I checked out some large post oaks with large dead branches thinking that might be what Strangalia virilis was breeding in but never saw any, and eventually I turned my attention to photographing a few interesting native plants that I found along the way.

Krameria lanceolata (trailing krameria).
Cirsium undulatum (wavyleaf thistle or gray thistle) inflorescence.

Cirsium undulatum (wavyleaf thistle or gray thistle) can be distinguished by its wavy leaves that are gray-green on both upper and lower surfaces.

Day 5 – Epilogue
We were tempted to do one last little bit of collecting on the way back to St. Louis, but since had pretty good luck during the last couple of days and the drive alone would take more than nine hours we decided to leave well enough alone and get home at a reasonable hour. A walk with Beauregard when I got home to stretch the post-drive legs was the perfect way to end the mini-vacation.

©️ Ted C. MacRae 2019

Best of BitB 2014

/ Ted C. MacRae / 20 Comments

Welcome to the 7th Annual “Best of BitB”, where I pick my favorite photographs from the past year. Before I do this, however, let me briefly recap the year 2014. The trend of increasing travel each year continued, with more days spent on the road than in any prior year. Travel for work over the past few years has settled into a familiar routine—touring soybean fields in Argentina in late February and early March, working in my own field trials at (previously three, now four) sites in Illinois and Tennessee from late May through late September, touring more soybean fields at sites across the southeastern U.S. during mid-September, returning to Argentina in October to finalize plans for field trials in the upcoming season, and—finally—attending/presenting at the Entomological Society of America (ESA) Meetings (this year in Portland, Oregon). This heavy travel load makes scheduling my own insect collecting trips a bit tricky, but I’m a persistent sort! In late May I traveled to Tennessee and Georgia with fellow buprestophile Joshua Basham and lab mate Nadeer Youseff to collect several rare jewel beetles, then in late June I collected prionids and jewel beetles in Colorado, New Mexico, and Oklahoma with Jeff Huether. In addition to these longer trips, I also managed to take advantage of my work travel to check out interesting natural habitats along the way to and from my field sites. I continue to give the occasional entomology seminar as well, speaking in March at “Day of Insects” in Ames, Iowa and here in St. Louis to the Entomology Natural History Group of the Webster Groves Nature Study Society in April and the Missouri Master Naturalists Confluence Chapter in December. On top of all this, I still managed to vacation with my family in Lake Tahoe during March and in Cabo San Lucas, Mexico during late July.

I say all this to highlight the fact that after all these years I still consider myself an entomologist with a camera rather than a bona fide insect photographer. The reason for this is that the science of entomology itself remains my primary focus—photography is simply one of the tools that I have come to use in my pursuit of the discipline. I don’t mean to imply that I don’t continue to work on my photography style and technique—because I do. But my style and technique are not goals in of themselves; rather, they are means to an end—that end being my entomological studies. With that said, I present my favorite BitB photographs from 2014. As in previous years, my photos are largely hand-held, in situ field shots that are intended to tell a natural history story in a (hopefully) aesthetic manner. Links to original posts are provided for each photo selection, and I welcome any comments you may have regarding which (if any) is your favorite and why—such feedback will be helpful for me as I continue to hone my craft. If you’re interested, here are my previous years’ picks for 2008, 2009, 2010, 2011, 2012 and 2013. Once again, thank you for your readership, and I hope to see you in 2015!

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

Paraselenis tersa (Boheman, 1854) | Cordoba Prov., Argentina

From Tortoise beetles on the job (posted April 20). This photograph of a tortoise beetle female over her egg mass illustrates maternal guarding behavior—rare in insects. The perfect lateral profile shot and clean, blue sky background also give the photo a pleasing aesthetic quality.

Who likes mole crickets?

Scapteriscus borellii Giglio-Tos, 1894 | Emanuel Co., Georgia

From Who likes mole crickets? (posted June 6). This has to be the most comical expression ever on the face of an insect!

Chrysobothris orono Frost, 1920 | South Cumberland State Park, Tennessee

Chrysobothris orono Frost, 1920 | South Cumberland State Park, Grundy Co., Tennessee

From Chrysobothris orono in Tennessee (posted July 29). I found this rare jewel beetle for the first time this year with the help of Josh Basham and Nadeer Youseff. The beetle itself is beautiful enough, but photographing it on a pine root with a presumed adult emergence hole adds considerable natural history interest to the photo. Rock substrate behind the root adds a pleasingly blurred background.

Buprestis (Stereosa) salisburyensis Herbst, 1801 | South Cumberland State Park, Tennessee.

Buprestis (Stereosa) salisburyensis Herbst, 1801 | South Cumberland State Park, Tennessee.

From The Buprestis tree (posted August 10). This was another of several jewel beetles that I found for the first time after more than three decades of collecting this group. I like the value contrast in this photo from the striking, metallic colors of the beetle against the nicely blurred cinnamon-colored pine bark of the tree on which it is sitting.

A "super moon" watches over a parasitized hornworm caterpillar.

A “super moon” watches over a parasitized hornworm caterpillar.

From A time of reckoning (posted August 13). I fully admit this is a composite photograph. Nevertheless, it is a faithful recreation of a true sight, and I don’t consider the use of composite techniques to overcome equipment shortcomings to be unethical. There is a haunting symmetry between the blood red moon—considered by some as a sign of the second coming—and the sad, parasitized caterpillar waiting for its inevitable demise.

The greatly expanded palps are thought to mimic beetle mandibles or spider pedipalps.

Phyllopalpus pulchellus Uhler, 1864 | Hickman Co., Kentucky

From My, what busy palps you have! (posted September 2). I’ve become quite fond of insect photos with the subject “peering” at me, the photographer”, from some unusual vantage point. The “pupils” in the eyes of this red-headed bush cricket give the insect an almost quizzical look.

Acmaeodera immaculata Horn, 1881 | vic. Vogel Canyon, Otero Co., Colorado.

Acmaeodera immaculata Horn, 1878 | vic. Vogel Canyon, Otero Co., Colorado.

From Sunset beetles (posted September 30). Taking photos of insects at sunset is a challenging and ephemeral experience—one has only a few minutes to take advantage of the unusual and serene colors it offers, while at the same time trying to determine the best camera and flash settings to use in the rapidly fading light. Of the several that I’ve tried, this one is my favorite because of the softly complimentary colors of the beetle, the flower upon which it is sitting, and the dying orange sky behind it. If I had to choose, I would probably pick this one as my favorite of the year because of the unusual and serene colors.

Megacyllene decora (Olivier, 1795) | Stoddard Co., Missouri

Megacyllene decora (Olivier, 1795) | Stoddard Co., Missouri

From Amorpha borer on goldenrod (posted October 5). I featured this very same species in Best of BitB 2012 but can’t resist choosing this second attempt at photographing the spectacularly beautiful adult—this time on goldenrod. As with the previous version this is a true in situ field photograph, hand held and using the left-hand technique to achieve precise composition against a clear blue sky—difficult to do with an insect of this size and using a 100-mm lens, but well worth the effort.

Buprestis (Knulliobuprestis) confluenta Say, 1823 | Woods Co., Oklahoma

Buprestis (Knulliobuprestis) confluenta Say, 1823 | Woods Co., Oklahoma

From A Buprestis hat-trick! (posted October 14). I didn’t take near as many of the classic “frontal portraits” this year, but this one of a jewel beetle that had eluded me for more than 30 years until this past June is perhaps my favorite of them all.

Agrilus concinnus Horn, 1891 | Stoddard Co., Missouri

Agrilus concinnus Horn, 1891 | Stoddard Co., Missouri

From North America’s Most Beautiful Agrilus Jewel Beetle (posted October 19). There was a time when this beetle was considered one of North America’s rarest species of jewel beetle. Several years worth of hunting by me and others revealed this beetle’s association with mallow and its unusually late adult activity period—the two combining to make this beetle “seem” rare. This year I succeeded in photographing the spectacular adult beetle.

Cacama valvata female ovipositing

Cacama valvata (Uhler, 1888) | Vogel Canyon, Otero Co., Colorado

From Scorching plains, screaming cactus (posted December 5). Insect photos are always better when they also show some aspect of the subject’s natural history. I was lucky to find this female cactus dodger cicada in the act of ovipositing into the dry stem of cholla cactus—in a position where I could get a perfect lateral profile with a clean, blue sky background.

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

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

From Cactus beetle redux (posted December 20). Cactus beetles can be difficult to photograph, but sometimes they cooperate by nicely posing on a pleasing pink flower bud with a blue sky in the background and the cactus spines forming a nice, fuzzy “halo” around the jet black beetle. There were surprisingly few cactus spines impaled in the control unit of my flash after this photo session.

I hope you’ve enjoyed this 2014 version of “Best of BitB” and look forward to seeing everyone in 2015.

Copyright © Ted C. MacRae 2015

Cactus beetle redux!

/ Ted C. MacRae / 11 Comments

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

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

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

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

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

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

The hazards of photographing cactus beetles.

The hazards of photographing cactus beetles.

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

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

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

REFERENCES:

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

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

© Ted C. MacRae 2014

A striking mallow caterpillar

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Tarache delecta ("mallow caterpillar") on Hibiscus lasiocarpus | Hickman Co., Kentucky

Tarache delecta (“mallow caterpillar”) on Hibiscus lasiocarpus | Hickman Co., Kentucky

Last month while searching stands of Hibiscus lasiocarpus (hairy rose mallow) in western Kentucky, I encountered this rather large caterpillar feeding on the foliage. I presumed that something as large and striking in appearance as this should be a cinch to identify by scanning through photos on BugGuide, and not surprisingly I found photographs (here, here and here) of two very similar looking caterpillars from Oklahoma posted by Charles Schurch Lewallen. None of the photos, however, had an identification associated with them other than subfamily Acontiinae (family Noctuidae). The contributor mentioned in one of the photos that he had found nothing similar in the Wagner (2005) “bible” (a book that I do not yet own but hope to soon). Armed with this scant information (but definitive knowledge of its host plant), I searched Noctuidae of North America and settled on Tarache delecta as a good possibility. According to that site, T. delecta is the only member of the Acontiinae that feeds on plants in the genus Hibiscus. The site references Crumb (1956) for a larval description, but more useful was a plate of black & white photos that I found in Weiss (1919) and that seemed to be a good match for the species I had photographed. Weiss (1919) refers to the larva as the “mallow caterpillar” and notes that full grown larvae are 34–36 mm in length and dark purple with black spots edged with orange—consistent with the caterpillar shown here.

Apparently this species has been considered a pest of ornamental mallows. Weiss (1919) notes that the larvae feed on the upper and lower leaf surfaces usually near the margins, making large holes in the leaves and sometime devouring parts of the bracts around the buds. I will also note that, in recommending control of the caterpillars, he states that “there does not seem to be any reason why spraying with arsenate of lead should not be successful.” My, how times have changed!

REFERENCE:

Crumb, S. E. 1956. The larvae of the Phalaenidae. U. S. Department of Agriculture, Technical Bulletin 1135, 356 pp. + 10 plates [Google Books].

Wagner, D. L. 2005. Caterpillars of Eastern North America: A Guide to Identification and Natural History. Princeton University Press, Princeton, New Jersey, 512 pp. [Amazon].

Weiss, H. B. 1919. The more important insect enemies of the rose-mallow in New Jersey. New Jersey Department of Agriculture, Bureau of Statistics and Inspection Circular 25, 9 pp. + 4 plates [Google Books].

© Ted C. MacRae 2014

A time of reckoning

/ Ted C. MacRae / 11 Comments

The sun shall be turned to darkness and the moon to blood, before the day of the Lord comes, the great and magnificent day.

A "super moon" watches over a parasitized hornworm caterpillar.

A “super moon” watches over a parasitized hornworm caterpillar.

I’m not normally one to quote Bible passages, but this line from Acts 2:20 seems appropriately ominous for the predicament of this poor hornworm caterpillar. The white objects on its back are the cocoons of tiny parasitic wasps in the family Braconidae who spent their entire lives inside the body of the growing caterpillar slowly eating away the inner tissues of the caterpillar, eventually consuming all but the most essential of its internal organs before exiting the skin and spinning their tiny, silken cocoons. Inside the cocoons the tiny grubs transformed into adult wasps, chewed their way out through the tip of the cocoon, and flew off to mate and find more hornworm caterpillars to parasitize. Its unwelcome guests now gone, this poor caterpillar has nothing to do but to sit and await its inevitable demise (which I suspect the caterpillar will not regard as such a “great and magnificent day”).

I found this caterpillar resting on a vine climbing a tree along the Mississippi River in southeast Missouri after setting up an ultraviolet light nearby and noticing the softly glowing cocoons. I was going to photograph it in situ, but I’ve learned that choice of background can have a dramatic effect on insect photographs, and the jumble of weeds and tree bark that would have comprised the background had I photographed the caterpillar where it sat seemed decidedly boring. I looked up and saw the blood red moon (a so called “super moon”) rising above the river in the eastern sky and decided to give it a try. The above photograph is actually a composite of two photographs—one of the caterpillar taken with flash and fairly normal camera settings, and another of the moon itself with aperture, shutter speed, and ISO all adjusted for very low light conditions (at least to the extent possible without a tripod). While this may not qualify in some people’s minds as a “real” photograph, it is nevertheless a true representation of what I actually saw, as I also made a number of attempts to capture both the insect and the moon in a single exposure. Since it is impossible to have both the insect (very close) and the moon (very far) in focus at the same time, the resulting photograph has a different, though still striking, effect, as shown in the photograph below:

IMG_6919_enh_1080x720

A more surrealistic version of the above photograph, with both caterpillar and moon captured in a single exposure.

This second photograph is actually much harder to take, as the moon does not appear in the viewfinder as the small, discrete, fuzzy-edged object resulting in the image, but rather as a large, blinding light that is difficult to place within the composition and know exactly where it will end up (at least, without a lot of trial and error). Add to that the fact that my camera image and histogram display panel is, at the moment, not functional, forcing me to “guess” if I had the right settings (in a situation where I’m well outside of my ‘normal’ settings for flash macrophotography). I’m a little surprised that I ended up with any usable photographs at all!

I’ve tried this type of photography with the sun as well—those interested to see how those photographs turned can find them at Sunset for another great collecting trip and Under Blood Red Skies.

© Ted C. MacRae 2014

“Picudo negro” (black weevil) on soybean in Argentina

/ Ted C. MacRae / 1 Comment

During my recent tour of soybean fields in Argentina, I traveled north to Tucumán Province and met with entomologists at the Estación Experimental Agroindustrial Obispo Columbre (“Obispo Columbre Agricultural Experiment Station”). This provincial station, established more than 100 years ago (1909), conducts research on agricultural and production technology for the Tucumán agricultural region. Focus crops include sugarcane, citrus, and grain—primarily soybean, corn, wheat, and dry beans, with research activities ranging from basic biological studies on emerging pests (such as Rhyssomatus subtilis, featured here) and Helicoverpa armigera (recently discovered in Brazil and now in northern Argentina) to resistance monitoring for transgenic crop target pests such as Spodoptera frugiperda, Helicoverpa zea, and Diatraea saccharalis.

Rhysommatus subtilis is a significant regional pest of soybean in Tucumán Province.

Figure 1. Rhysommatus subtilis is a significant regional pest of soybean in Tucumán Province.

In recent years the laboratory has had a dedicated effort to characterize the biology and economic impact of R. subtilis on soybean (Fig. 1). Although practically limited to soybean growing regions in Tucumán Province, this insect has increased greatly in importance within that area in recent years along with two other weevils: Sternechus subsignatus (picudo grande, or “big weevil”) and Promecops carinicollis (picudo chico, or “little weevil”) (Casmús et al. 2010). Of the three species, S. subsignatus is perhaps the most serious because of its stem boring habit that can result in stand loss, while P. carinicollis is the least because its feeding is largely limited to leaves. Rhyssomatus subtilis is intermediate in importance, primarily due to larval feeding within developing pods.

Adults feed by clipping leaf petioles. The impact is minor, but it is a characteristic sign of adult presence.

Figure 2. Adults feed by clipping leaf petioles. The impact is minor but signals adult presence.

I have not yet seen S. subsignatus in soybean fields in the area, but I saw P. carinicollis during last year’s tour (see this post) and encountered R. subtilis at several locations during this year’s tour. Rhyssomatus subtilis presence in soybean can be detected even before the adults are noticed by the occurrence of clipped leaflets (Fig. 2), which is caused by adults feeding on leaf petioles.

Adult females chew a small hole into the wall of the developing pod, not to feed but for oviposition

Figure 3. Adult females chew small holes into developing pods, not to feed but for oviposition.

Leaf feeding has little if any impact on the crop; however, as the crop enters pod development stages of growth adult females begin chewing small holes in the pod walls (Fig. 3), not for feeding but for oviposition. Eggs are laid singly in the pod (Fig. 4), with larvae (Fig. 5) feeding on the developing seeds within.

Eggs are laid singly inside the pod.

Figure 4. Eggs are laid singly inside the pod.

This manner of feeding by the larva not only directly impacts yield but also hampers efforts to control active infestations by preventing contact with foliar-applied insecticides. Eventually the larvae mature, exit the pod, and drop to the soil where they burrow, pupate, and emerge as adults during the next cropping season while plants are still in early to mid-vegetative stages of growth.

This neonate larva has just hatched and will feed within the pod on developing seeds.

Figure 5. This neonate larva has just hatched and will feed within the pod on developing seeds.

Management techniques include rotation with grass crops to reduce populations (the weevil is oligophagous on soybean and dry beans), use of insecticide seed treatments to control adults during early vegetative stages of growth, and subsequent use of foliar insecticide applications if adults remain after the effect of seed treatments begins to diminish.

REFERENCE:

Casmús, A., M. G. Socías, L. Cazado, G. Gastaminza, C. Prado, E. Escobar, A. Rovati, E. Willink, M. Devani & R. Avila. 2010. El picudo negro de la vaina de soja en el NOA. Estación Experimental Agroindustrial Obispo Columbre, Tucumán, Argentina, 8 pp.

Copyright © Ted C. MacRae 2014

Not all soybean caterpillars are ‘ugly’!

/ Ted C. MacRae / 4 Comments

Although photographs of beetles dominate this site (they are my true love, after all), I am nevertheless an agricultural entomologist by day and, as such, find occasion to post photos of the insects I encounter in my area of expertise—soybean. I think by and large those soybean insects—especially the caterpillars—don’t generate as much interest as the beetles that I feature. I guess this is understandable—caterpillars of the agricultural pest variety seem generally unable to compete with the visual and behavioral charisma exhibited by jewel beetles, tiger beetles, tortoise beetles, etc. Here, however, is an example of a soybean caterpillar that is as beautiful as any beetle you will find—the larva of the silver-spotted skipper, Epargyreus clarus (Lepidoptera: Hesperiidae). Not only are the colors to die for, but that comically big head makes for a truly laughable frontal portrait!

Epargyreus clarus (silver-spotted skipper) late-instar larva on soybean | Baton Rouge, Louisiana

Epargyreus clarus (silver-spotted skipper) late-instar larva on soybean | Baton Rouge, Louisiana

This particular individual was found last September in a soybean field near Baton Rouge, Louisiana (amazingly, this is the first insect I have featured from Louisiana). Silver-spotted skippers feed on a wide variety of plants in the family Fabaceae (of which soybean is a member), but their occurrence on soybean rarely reaches levels that cause any economic impact. Normally the caterpillars hide during the day in a silken nest constructed by folding over a leaflet or tying adjacent leaflets together, emerging only at night to feed.

What a pretty face!

What a pretty face!

I suppose the orange spots on the head are intended to serve as false eye spots—for some reason the larger the eyes the more a potential predator seems to take pause before deciding to eat something. The actual eyes can be seen along the outer edge of the orange spot as a row of simple ocelli—incapable of forming sharp images and serving as little more than light and motion detectors. I can’t even begin to speculate on the function of the curious asperate/rugose texture of the head!

Copyright © Ted C. MacRae 2014

Tortoise beetles on the job

/ Ted C. MacRae / 7 Comments

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

Botanochara angulata?

Botanochara angulata? mating pair | Córdoba Prov., Argentina

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

Paraselenis tersa?

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

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

Undetermined cassidine larvae.

A single tortoise beetle larva was encountered.

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

Undetermined cassidine larva.

Spiky spines and a pile of poop make formidable defenses.

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

Ted MacRae photographing tortoise beetles.

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

© Ted C. MacRae 2014