Melyridae

9th Annual Fall Tiger Beetle Trip: Day 3.2

/ Ted C. MacRae / 4 Comments

My plan to retrieve beetle-infested wood in Oklahoma’s Glass Mountains has morphed from a quick stop to an all-morning affair, and by the time I loaded up the bundles it was well past noon. Fortunately, my next planned stop—Alabaster Caverns State Park—was only about a 90-minute drive, meaning I would still have plenty of time to give the area a good look. Unlike the Glass Mountains, with its gypsum-capped, flat-topped mesas rising above the surrounding landscape, Alabaster Caverns is level ground fissured by deep, rugged canyons that have eroded through the gypsum cap into the soft, underlying red clay. Nevertheless, both sites are part of the same Gypsum/Red Hills geological formation, so their associated flora and entomofauna are also similar. It was during my original visit to Alabaster Caverns back in 2009 that I found robust populations of Cylindera celeripes (Swift Tiger Beetle), and in October of the following year I discovered its previously unknown larva. My originally intent in coming here this time was to look for Cicindela pulchra (Beautiful Tiger Beetle), but since I had failed to find this species in the Glass Mountains I had little optimism that I would find it here as well. Still, it’s a beautiful park and I was anxious to see some of the canyon areas that I had not explored on previous visits, after which my trip would take a turn to the south.

Alabaster Caverns State Park, Woodward Co., Oklahoma

As I expected, no amount of searching on the flats above showed any evidence of C. pulchra, and I saw pretty much the same assortment of beetles visiting the yellow-flowered Heterotheca stenophylla (stiffleaf false goldenaster) and Gutierezzia sarothrae (broom snakeweed) blooming in profusion that I had seen on Day 2 at Gloss Mountains State Park. Since I had neglected to photograph the gray blister beetle (family Meloidae, genus Epicauta) that I was seeing so commonly the day before, I decided I should go ahead and take advantage of the opportunity while I had it. As I mentioned in my Day 2 post, these beetles were seen almost exclusively on Gutierezzia, and shown below are two of the better photos that I ended up with.

Epicauta sp. | Alabaster Caverns State Park, Woodward Co., Oklahoma

Mouthparts at 3X—love that pollen!

Another species that I saw very commonly were tiny little beetles feeding exclusively on the Heterotheca flowers. Measuring less than 5mm in length, a majority of flowers had at least one of these small gray beetles, and sometimes as many as four or five. Just based on appearance I suspected they represented something in or related to the soft-winged flower beetles (family Melyridae), and in fact they are a dead ringer for the species Listrus senilis(compare to these photos of the MCZ type specimen). This species seems to occur abundantly throughout the Great Plains (Mawdsley 1999) as far south as Texas (BugGuide). The small size of these beetles made them much more difficult to photograph, so my ‘keeper’ rate was lower than for the Epicauta beetle, but a few turned out okay:

Listrus senilis on Heterotheca stenophylla | Alabaster Caverns State Park, Woodward Co., Oklahoma

Listrus senilis at 5X—another pollen lover!

The most significant find of the day, however, was also the most unexpected—I saw numerous individuals of an Acmaeodera jewel beetle feeding on the Heterotheca flowers. Why is this so unexpected? Because throughout most of North America members of the genus Acmaeodera are almost exclusively active as adults during spring and early summer. Those occurring in southeastern Arizona are found more during July and August, a result of the summer monsoon season, but truly fall-active species are limited to a few occurring in the Lower Rio Grande Valley of south Texas. When I saw the first one I presumed it was a late season straggler, but then I saw another, and another. It was clear by their numbers that now is their activity period. I do not know what species they represent, but I took numerous photos and will post them once I have made an identification. It remains to be seen whether this is an unusual habit for a known species (more likely) or a previously unknown species (less likely, though new species of Acmaoeodera continue to be discovered routinely in the U.S.)—stay tuned!

REFERENCE:

Mawdsley, J. R. 1999. Redescription and notes on the biology of Amecocerus senilis (LeConte) (Coleoptera: Melyridae: Dasytinae). Journal of the New York Entomological Society 107(1):68-72.

Copyright © Ted C. MacRae 2012

The most common beetle in Argentina

/ Ted C. MacRae / 6 Comments

Astylus atromaculatus | Buenos Aires Province, Argentina

I don’t know if this is truly the case, but Astylus atromaculatus (family Melyridae) is one of only a few beetles in the country that actually has two Spanish common names—”astylus moteado” and “siete de oro” (meaning “spotted astylus” and “seven of gold”, both names referring to black splotches on the elytra). It is also the only beetle that I’ve seen everywhere I’ve been in the country—north and south, soybean fields and cornfields, countryside and city. I have yet to visit a soybean field where I don’t see them, perhaps nibbling on a leaf here and there but mostly just mating, and they can be downright overwhelming in cornfields (see this post with photos of the adults dripping from corn tassels, literally!). For all their ubiquity, however, their economic impact seems more nuisance than substantive. Corn breeders complain about interference during tasseling, and larval feeding on seeds during or just after germination seems to be on the rise due to increased use of conservation tillage, but overall this species seems to be more bark than bite.

Copyright © Ted C. MacRae 2012

Return to La Reserva Ecológica Costanera Sur

/ Ted C. MacRae / 14 Comments

Last March I discovered —a gem of natural beauty in the heart of Buenos Aires, Argentina.  Though its origins are semi-artificial, its biota a mix of native and introduced species, and its pathways continually choked with pedestrians and cyclists, for me it is a refuge—a place where I can spend an entire day looking for insects without ever retracing my footsteps.  Last Sunday after arriving in Buenos Aires, I couldn’t check into my hotel and change into my “bug collecting clothes” fast enough before making a beeline to the Reserve just a few blocks away.  I “discovered” a huge area on the east side of the Preserve that I hadn’t found during my last visit that was devoid of paved paths—and thus people—and spent the next several hours rummaging through the brush looking for insects to photograph.  Early November is early spring in Buenos Aires, and insect activity was still just beginning.  I did find a number of insects to photograph, though not as many as I had found during my early March visit.

This butterfly, which I regard as Actinote carycina (Yellow Lazy), was common around stands of a purple-flowered plant.  I watched this particular individual flit endlessly back and forth in front of one particular stand, rarely pausing long enough to allow a shot or two before resuming its patrols.  Vigorous aerial battles ensued every time another individual approached the stand, and although I can’t say for sure that it was this individual that always won, the same patrolling flight pattern resumed as soon as one of the contestants flew away.

Beetles were scarce, but I saw this particular species of Melyridae (presumably in the genus Astylus, and thus a close relative of Astylus atromaculatus or “spotted maize beetle”).  I don’t normally do random “bug-on-a-flower” photos, but I’ve recently become enamored with the use of “blue sky technique” for insect macrophotography and thought the red and black color of the beetle against the yellow flower it was feeding on was well suited for a blue background.  The beetle was quite small (only ~6 mm in length), thus requiring the 65mm 1–5X lens and full-flash illumination.  Normally this would result in a black background unless something is placed behind the subject, and I suppose I could just carry around a colored cards for placing behind subjects to get whatever color background I want.  However, there is something appealing to me in having the ability to achieve a blue sky by actually using the sky, despite the trickiness of the technique.  In this case, I  played with ISO settings of 400–640 and shutter speeds of 1/100 to 1/125 sec (settling at the high end of each range for this photo) to get the color of the sky true, then used low F.E.C. settings (-1 2/3 in this case) to temper the illumination of the subject.  I’m still not completely happy with the results—there is more motion blur in the photo than I would like, and I burned the yellows a little too much as well.  I think ISO800 and F.E.C. -2 or even lower would have given better results.  At any rate, this photo was the best of the bunch, and it will have to do.

Copyright © Ted C. MacRae 2011