Bichos Argentinos #4 – Balancing Act

Nezara viridula (southern green stink bug) | Pergamino, Pcia. Buenos Aires, Argentina

I encountered this adult Nezara viridula (southern green stink bug) (Hemiptera: Pentatomidae) in a soybean field in Buenos Aires Province, Argentina.  I liked the way it balanced itself on the leaf on which it was sitting to keep its body level.

Copyright © Ted C. MacRae 2011

Bichos Argentinos #3 – “Bicho Torito”

Diloboderus abderus, male | Buenos Aires, Argentina

In her appeal for submissions for her upcoming issue of An Inordinate Fondness, Susannah lamented the paucity of beetles in the closing weeks of her northern winter and mentioned in passing that even I had gone more than a week without posting about this great order.  I hadn’t realized that myself, so here I present Diloboderus abderus, one of the beetles that I encountered during my visit last weekend to La Reserva Ecológica Costanera Sur in Buenos Aires, Argentina.  This species, known commonly in Argentina as bicho torito (“little bull bug”) is common enough in Argentina and southern Brazil, where its white grub larvae have become somewhat of a pest in lawns, pastures, and grass crops such as wheat by way of feeding on the roots.  I first encountered this species during one of my previous trips to Argentina, where during a rain storm I saw literally hundreds of adults emerging from mowed grass medians in the city streets of Pergamino.  These photographs show two of numerous dead individuals that I found laying on the ground of similar medians just outside the reserve.  As with many scarab beetles in the subfamily Dynastinae (containing also the recently featured Dynastes tityus), males (above) are armed with pronotal and cephalic horns – presumably for use in sexual combat – while females (below) are unarmed.

Diloboderus abderus, female | Buenos Aires, Argentina

Copyright © Ted C. MacRae 2011

Bichos Argentinos #2 – Pseudomyrmex sp.

Pseudomyrmex sp. (twig ant) | Reserva Ecológica Costanera Sur, Buenos Aires, Argentina

One of the insects I tracked at La Reserva Ecológica Costanera Sur in Buenos Aires, Argentina last weekend was this twig ant in the genus Pseudomyrmex.  I had noticed these slender, wasp-like ants previously on trips to the U.S. desert southwest, but it wasn’t until I read a couple of recent posts about them at Myrmecos and 6legs2many that I knew specifically what they were. 

Alex characterizes these ants as “delightfully gentle, quirky little insects.”  What he didn’t mention is how frenetic and unceasing they are as they forage amongst the shrubbery.  I must have taken a couple dozen shots of several individuals over the course of the day, deleting every single one on the spot because I couldn’t get a clear, close, focused, nicely composed, unobstructed image.  Their habit of crawling rapidly along slender twigs is problematic enough, with little opportunity to brace the camera against anything steady and spend time composing the shot.  Add to that the frequently thorny nature of the trees they were roaming and their annoying habit of darting around to the backside of whatever twig they were on whilst trying to follow them in the viewfinder, and I almost decided I’d met my match and could do without the shot.  In the latter part of the day I encountered this individual, and as I already had my 65mm lens mounted I decided to give it another try.  I can’t say that I actually figured out the secret to getting the shot, but rather that I just lucked out and happened to have hit the shutter release at just the right moment – and with reasonable focus – as I tracked the ant along the branch on which it was crawling.  It was the only shot of one of these ants that stayed on the card that day.

The genus is huge, with 209 species occurring primarily throughout the Neotropics.  As a result, it would be foolish for me to even attempt a species ID.  Still, I can’t help noticing its great resemblance to this photo of Pseudomyrmex phyllophilus, taken by Alex in – you guessed it, Buenos Aires, Argentina.  I’ll wait for the correction, but in the off-chance that I’m right I think I deserve points on somebody’s scorecard!

Copyright © Ted C. MacRae 2011

Bichos Argentinos #1 – Eristalinus taeniops

Eristalinus taeniops - a hover fly in the family Syrphidae

It figures that perhaps the most striking insect I saw at La Reserva Ecológica Costanera Sur in Buenos Aires, Argentina would be an introduced species, as the area itself is a man-made reconstruction of the wet Pampas grasslands endemic to coastal areas of the Rio de la Plata.  My identification of this fly as Eristalinus taeniops is based on its great resemblance to the many online photographs that exist from both South America and the U.S. and also the Old World where it is apparently native.  I found no more authoritative sources with which to confirm the ID, so this online comparative will have to do (muscophiles feel free to comment or correct). 

According to BugGuide, E. taeniops is a recent import to the U.S. from Africa, and in fact it has apparently successfully invaded much of the world.  I suppose most folks will be inclined to forgive the fly for all this because of its strikingly patterned eyes, which I would have dearly loved to have gotten in tight for a closeup.  This shot with the 100mm lens dialed in to the max (and only slightly cropped for composition), however, was the only one I managed – the fly bolted as I quickly tried to switch to the 65mm lens, and although I saw two more individuals afterwards, I couldn’t get anywhere close to them in the day’s heat.  Eyes notwithstanding, the species is a near perfect mimic of a honey bee, making one wonder what selective pressures drove the development of these fantastically contrasting eyes.

Copyright © Ted C. MacRae 2011

La Reserva Ecologica Costanera Sur

Reserva Ecológica Costanera Sur, Buenos Aires, Argentina.

I spent this past weekend in Buenos Aires, Argentina before embarking on a one-week whirlwind tour to visit field sites in several other parts of the country.  It was supposed to be a short rest stop, but I can do nothing of the sort when there are exotic lands to explore.  Despite its rank as the fourth largest city in South America and the location of my hotel in the heart of downtown, only a short walk was needed to arrive at Reserva Ecológica Costanera Sur, a 350-hectare park located on the banks of the Rio de la Plata.  Originating as a debris field from construction during the 1970s, sedimentation and subsequent revegetation have created a naturalistic setting reminiscent of the original wet Pampas grasslands that occurred in the area.

A system of levees with trails courses through the wet grasslands.

Coursing through the area is a system of levees topped with gravel walking/biking trails that have become flanked with woody vegetation.  Native species such as ceibo (Erythrina crista-galli) and palo borracho (Chorisia speciosa) are common, although exotics such as Canary palms (above photo) have also become established.  In total, more than 11 km of trails are available, and having as much time as I desired on Sunday to explore the area, I walked every one of them once (and some twice) for a total hike of close to 15 km (not counting my morning walk to the area and then back to my hotel during late afternoon).  I wouldn’t say the area was teeming with insects, and those that I did encounter are not too dissimilar from those I am more familiar with in North America.  However, this is the southern Neotropics, so just about everything I encountered was something I had not seen before.  I went photography-crazy, snapping more than 250 shots on the day (and keeping about 100).

Leptodactylus ocellatus (rana criolla).

This frog was the first thing I encountered, even before walking through the Reserve gates.  Using the galleries at this fan site I believe it to represent Leptodactylus ocellatus (rana criolla, or “Creole frog”).  He was a sad sight when I first saw him – dry and dusty on the sidewalk outside of the Reserve.  I passed him by at first thinking he must be dead, then came back when my conscious started complaining, only to find him still alive.  I bathed him in water from my bottle, which perked him up rather quickly (not to mention making him much more photogenic!).  After a few photos, he revived sufficiently to jump off the stone wall bordering the Reserve into the grassy marsh.  I had done my good deed for the day.

Leptodactylus ocellatus (rana criolla) - my attempt at a natural light closeup.

Parabuteo unicinctus unicinctus (Gavilán Mixto) (I think!).

Also just before entering the Reserve gates, I scared up this hawk who flew a short distance ahead and landed on a post facing me.  Now, I have never once in my life attempted to photograph a bird, and with my longest lens being only my 100mm macro I’m ill-equipped for such even if I wanted to.  However, the hawk did not fly too quickly as I cautiously re-approached, and when I was within range I decided to give it a try.  I carefully crouched to ready my equipment and then cautiously rose to take a shot, and right then the hawk decided to take off.  Not a great shot, of course, but not bad either – especially for a first bird shot ever, and good enough to give me some amount of confidence in my ID as Parabuteo unicinctus (Gavilán Mixto, or “Mixed Hawk” – known in the U.S. as Harris’ Hawk).

Riodina lysippoides (Danzarina Chica)

Insect activity was rather light for the first couple hours after I arrived, but as the day began to heat up so did the number and diversity of the insects that I encountered.  While I waited for activity to pick up, I saw this pretty little butterfly that seemed surely a type of metalmark (family Riodinidae) and that I later identified as Riodina lysippoides (Danzarina Chica, or “Smaller Dancer”).  Shortly after taking this photo, I encountered another photographer who was obviously after insects.  I approached him and introduced myself to see what he was looking for, and it was butterflies.  I showed him my photo, but he did not know the name of the butterfly, only commenting that it was “bastante común” (common enough).  I’m confident in my ID, but this North American beetle collector won’t be too embarrassed if one of you lepidopterists needs to provide a correction.  I did see one other photographer that day as well, presumably after birds based on the yard-long lens he was carrying, but I did not talk to him.  Otherwise, I got plenty of strange looks from the hordes of walkers, runners, bikers, and picnickers that had come out to enjoy this Carnival weekend Sunday!

Copyright © Ted C. MacRae 2011

Saludos de Argentina

I was hoping somebody might try to guess in which city the photos in the previous post were taken, but nobody took the bait.  My allusion to a population of 13.1 million people makes for a rather short list, and in fact they were taken in Buenos Aires, Argentina.  I’m on another business trip, and though I’ve traveled to Argentina numerous times, all of my previous trips were prior to my owning a camera of any kind.  This trip is turning out to be much more frenetic than my Brazil trip of this past January, with not near as much time or opportunity to wander the gardens looking for insects to photograph; however, I did have a full day to myself in Buenos Aires yesterday, which was spent in its entirety at the nearby Reserva Ecológica Costanera Sur.  It’s summer here, although there is definitely a late-season, temperate feel to it.  Nevertheless, I found a number of interesting insects to photograph, and I promise to share some of those photos in the coming weeks.  For now, I hope you’ll indulge me a few more traditional sightseeing photos of what I consider to be one of the world’s most beautiful mega-cities.  I’m not sure when I’ll get to update again – I’m traveling to a number of locations in the country’s interior, and internet service in the places I’ve been and will be over the next week is usually either expensive or non-existent.

''Palo boraccho'' (Chorisia speciosa) trees (background) in full bloom in Plaza de San Martin

The elegant ''Calle Florida" in Buenos Aires centro.

''Galeria Pacifico'' on calle Florida - a national historic monument.

Puerto Madero Waterfront on the Rio de la Plata boasts trendy architecture and upscale restaurants.

''Puente de la Mujer'' (Woman's Bridge) on the Puerto Madero Waterfront. Commissioned in 2001, this unique asymmetrical cantilever pedestrian bridge is also a swing bridge that rotates 90 degrees to allow water traffic to pass.

Early morning view from my hotel room in the heart of Buenos Aires.

Las Nazarenas - my favorite restaurant in all of Argentina - serves traditional Argentine meats and wine.

Can you guess what is the botanical representation of this sculpture in the Puerto Madero district?

Copyright © Ted C. MacRae 2011

North America’s largest scarab beetle

Dynastes tityus male - USA: Missouri, Jefferson Co., DeSoto

As one of North America’s largest, most written about, and most photographed beetles, Dynastes tityus (eastern Hercules beetle) hardly needs an introduction.  I photographed this male specimen from my collection back in December while testing my DIY diffuser for the MT-24EX twin flash and 100mm macro lens.  It’s a good test subject for such – its glossy exoskeleton may be beauty to the eye but is the bane of flash photographers, and its nearly 60mm of length demand a huge subject-to-lens distance that gives even the largest lens-mounted flash a small apparent size.  Nevertheless, the diffuser did a pretty good job of creating even illumination and preventing harsh specular highlights, giving almost the effect of an indirect strobe in a white box.

Dense setae adorn the underside of the thoracic horn of the male.

I hadn’t really noticed until I took the photos the dense adornment of setae (hairs) on the underside of the thoracic horn.  While setae in insects most often perform a tactile function, the density and placement on the horns of the males of these beetles makes me wonder if they might serve more of a display function.

Despite the overwhelming popularity of this beetle amongst hobbyist breeders and its widespread occurrence across the eastern United States (and the internet), it is not one that I have encountered with much frequency myself.  I suspect this is due to the position of Missouri near its western limit of distribution – likely a function of the species’ preference for moist treehole cavities with rotting wood in which the larvae can develop.  This particular specimen was given to me many years ago by a nursery grower in Jefferson Co. during my first job out of graduate school – before I’d ever found one myself, but since then I’ve encountered perhaps half a dozen or so at blacklights in mesic forests across the eastern Ozark Highlands.  Most recently (last summer) I found a female sitting on my driveway, apparently attracted to the mercury vapor lamp above the garage that I leave on occasionally during the months of June and July just for such purpose.

Copyright © Ted C. MacRae 2011