Arthropoda

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

A black background is better… sometimes

/ Ted C. MacRae / 6 Comments

Eriophora ravilla (a tropical orb weaver) | Pinellas Co., Florida

If there is one subject that causes more disagreement among macrophotographers, it is the pitch black background. Granted, black backgrounds are common—almost ubiquitous in macrophotography, since they are easily created by using full flash illumination and ensuring that nothing lies behind the subject close enough to reflect the light from the flash. Detractors, however, claim that it gives subjects an ‘unnatural’ look, as they are rarely seen this way in nature. This may be true, but I still believe that for some subjects the black background simply cannot be beat for its aesthetics, even if the subject is not normally seen in this manner. Take, for example, the Great Plains ladies’-tresses orchid—nothing but a pitch black background could better showcase the delicate, white blossom and its almost crystalline lower lip!

That said, however, there are some subjects for which a pitch black background actually can be considered a ‘normal’ background. This tropical orb weaver spider (Eriophora ravilla) is one example. Unlike many other members of the family Araneidae (orb weavers), species in this genus are strictly nocturnal and not seen hanging on a web during daylight hours. Hiding in a curled leaf during the day, they emerge at night and build a large web (up to 1 meter wide), only to consume it by morning and return to their hiding place until the next evening. My nephew Jack and daughter Madison and I first saw this spider during our nighttime foray into the intertidal mangrove marsh behind my sister-in-law’s condominium in Seminole, Florida last month while discovering rare, endemic beetles and their larvae. Knowing that it would likely build its web in the same place on subsequent evenings, I went out a few nights later with my camera and took a few shots.

Some claim that black backgrounds are undesirable for even nocturnal subjects; that there is nothing ‘natural’ about an artificial, narrow beam of light illuminating a single subject at night since no animal other than a person with a flashlight would see something like this. This contention seems a little strained, as one could take such a stance on illumination of any kind. Technically speaking even colors don’t actually exist, so the rendering of subject images on camera film/sensor, whether by natural or artificial illumination,  is itself biased towards human sensibilities. Regardless, the sight of an eerily glowing spider hanging in the blackness strikes a familiar chord with anyone who has wandered the bush by night. A black background not only recreates that human experience, but also emphasizes the subject’s (in this case strictly) nocturnal nature with stark elegance.

At first I took this spider to represent the very common barn spider, Neosona crucifera—widespread across North America. However, after noting the dark femora and yellow “shoulders” of the abdomen I began to rethink that ID. Fortunately, I took one photo of the ventral side (not shown) that shows well the color pattern diagnostic for the circum-Caribbean species E. ravilla.

Copyright © Ted C. MacRae

And the winner is…

/ Ted C. MacRae / 13 Comments

Okay, time to fess up on which of my photos was selected for the 2013 ESA World of Insects Calendar, but before I do let me say that getting readers’ comments on which one they thought was selected proved to be a very interesting exercise. The final tally is as follows (I gave ½ a vote for mentions of a photo as a second choice):

1. Trimerotropis saxatilis nymph – 4½ votes
2. Crossidius coralinus fulgidus – 3½ votes
3. Tetracha floridana – 3 votes
4. Buprestis rufipes – 2 votes
4. Edessa meditabunda eggs – 2 votes
6. Megaphasma denticrus – 1 vote

My personal favorites were Buprestis rufipes, Crossidius coralinus fulgidus and Tetracha floridana, with the second having what I thought was the best “calendar appeal.” I also thought the Trimerotropis saxatilis was strong for its natural history back story. It thus comes as no surprise that these were the top four vote-getters among those who commented.

The two photos that did not receive any votes are interesting—Spissistilus festinus, because the post containing that photo is one of the Top 5 posts on this blog (based on page views); and Cicindela formosa generosa, because that was the photo selected by ESA for their 2013 Calendar! I went back and forth on whether to include the photo in the final selections, but it won out over some others I was considering because of its composition—not many tiger beetle closeups contain as much scale and depth. I guess that’s what ESA like about it as well, but whatever the reason it seems I need to develop a better sense of what photo judges are looking for.

Since nobody guessed the correct photo, I’m going to give all who commented 5 “participation” points, and those of you who used italics with scientific names will get an additional 2 bonus points. Brady Richards maintains his spot atop the overalls in BitB Challenge Session #6 with 66 points, but Mr. Phidippus‘ 58 points moves him into second place over Sam Heads with 54 points.

For those who did not vote for this photo (or, everybody!), maybe access to this 1680×1120 version of the photo (click to enlarge) will help change your minds.

Cicindela formosa generosa (Coleoptera: Carabidae: Cicindelinae) – eastern big sand tiger beetle

Copyright © Ted C. MacRae 2012

2013 ESA World of Insects Calendar Selection

/ Ted C. MacRae / 20 Comments

Today I received word from Richard Levine at the Entomological Society of America that one of my photos had been selected for the 2013 version of their famed World of Insects Calendar!

Excuse me for a moment please… (pumps fist, stirs the pot, does a very bad moon walk…)

Okay, I’m back. Honestly, this is an honor that I did not expect—at least not yet. Historically dominated by such giants in the world of insect macrophotography as Piotr Naskrecki,  Thomas Myers, and others, competition for ESA’s World of Insects Calendar is fierce. Last year more than 500 photographs were submitted for 13 slots (12 months and an introductory page) by 98 photographers from around the world. I was one of those photographers, though not selected (no surprise as I was a first-time submitter). However, I took great pleasure in seeing fellow bug blogger Adrian Thysse nab two of the 2012 slots, and I increased my resolve to try again for next year with a selection of eight mostly newer photographs.

At the suggestion of Dave Stone, I present each of those photos below along with a short description of why I submitted it. However, I’m not going to tell you which photo ultimately was selected—I thought it might be fun to see which photo you think was selected and why. As added incentive for guessing, I’m going to award 10 BitB Challenge points to each person who correctly picks the selected photograph. BitB Challenge Session #6 is coming down to the wire, so this could have a big impact on the overall standings.

The 2013 Calendar will become available for sale later this year (probably October) at the ESA website—last year’s version cost only $12 (discounted to $8 for ESA members, and free for those attending the annual meeting [which I will be attending this year]).

Megaphasma denticrus (Phasmida: Diapheromeridae) – giant walkingstick

From North America’s longest insect (21 Aug 2009).  This is one of my earlier super-closeup attempts. I liked the combination of blue and brown colors on the black background.

Buprestis rufipes (Coleoptera: Buprestidae) – redbellied Buprestis

From Special Delivery (13 July 2010).  The use of a white box shows off the brilliant (and difficult-to-photograph) metallic colors well, and I like the animated look of the slightly cocked head.

Edessa meditabunda (Hemiptera: Pentatomidae) – alquiche chico

From  (18 May 2011). I found these Edessa meditabunda stink bug eggs on the underside of a soybean leaf in Argentina almost ready to hatch. The developing eye spots in each egg gives the photo a “cute” factor rarely seen in such super close-ups.

Cicindela formosa generosa (Coleoptera: Carabidae: Cicindelinae) – eastern big sand tiger beetle

From  (10 May 2011). I like this slightly panned out view because of the sense of scale and landscape created by the inclusion of the plantlets and the view over the small rise.

Trimerotropis saxatilis (Orthoptera: Acrididae) – lichen grasshopper

From  (15 July 2011). Some of my favorite insect photos are not only those that show the bug in all its glory, but also tell a story about its natural history. This nymph is almost invisible when sitting on the lichens that cover the sandstone exposures in its preferred glade habitat. 

Tetracha floridana (Coleoptera: Carabidae: Cicindelinae) – Florida metallic tiger beetle

From  (23 August 2011). I used extension tubes to improve the quality of flash lighting (decreased lens to subject distance results in greater apparent light size), and I like the symmetry of the composition.

Spissistilus festinus (Hemiptera: Membracidae) – threecornered alfalfa hopper

From  (17 September 2011). Even though both the insect and the background are green, there is sufficient value contrast to create a pleasing composition, punctuated by the bizarre zig-zag pattern of the eyes.

Crossidius coralinus fulgidus (Coleoptera: Cerambycidae) – a rabbitbrush longhorned beetle

From  (4 October 2011). The blue sky background provides a pleasing contrast with the colors of this particular beetle and flowers.

Copyright © Ted C. MacRae 2012

Even a 12-year old can discover the larva of a rare, endemic species!

/ Ted C. MacRae / 13 Comments

Since discovering the larva of the rare, endemic Florida metallic tiger beetle (Tetracha floridana) in the small, intertidal mangrove marsh behind my sister-in-law’s condominium in Seminole, Florida three years ago, I’ve looked forward to subsequent visits to see the adults (they’re nocturnal) and gather additional material needed to write the larval description. I had to wait a few days on this year’s trip due to rain (it is Florida, after all), but eventually a dry evening came along and I began “suiting up” for my nighttime foray. Much to my delight, my 12-year old nephew Jack wanted to come with me. Jack had never been in the field with me before, but according to his mom he has become quite interested of late in science and biology. My daughter Maddie, also 12 years old (and a veteran of many trips to the field with me), also wanted to go, so together the three of us slathered on the insect repellent and headed into the dark towards the marsh.

Larva of Micronaspis floridana (Florida intertidal firefly) | Pinellas Co., Florida

We had only my headlamp as a light source, so the kids trailed behind me as I picked a line through the brush, across a small creek, and onto a ridge that snakes through the marsh that marked one of the areas where I had seen good numbers of the beetles last year. We collected a small number to keep alive and place in a terrarium of native soil, the hope being that they would lay eggs so I could obtain some 1st-instar larvae for the formal description, but what I was really looking for were larval burrows. As we (well, I) searched the ground in front of me with the lamp and the kids trailed behind me in the dark, Jack suddenly stopped and said, “What’s that?” I shone my light to where he was pointing but didn’t see anything and so resumed my search. Right away he said, “There it is again.” I asked if it was a rabbit (we’d seen them at the edge of the marsh during the day), and he said, “No, it’s like a light or something.” I turned off the lamp, and gradually the faint, green glow reappeared. I recognized the source of the light instantly as that of a larval firefly, although truthfully I have never actually seen an actual firefly larva. Seeing a great teaching moment for the kids, we walked to the light, knelt down, and shone the lamp directly on the ground from where the light was coming to find the small (~10 mm long) larva moving slowly through the moist, algae-covered rocks. It had the classic, retractable firefly head and curiously quadruply-spined tergites. I congratulated Jack on finding the larva, emphasizing that I would have never seen it myself had he not been there and been so observant despite not having a lamp.

Larvae of this species exhibit the retractable head characteristic of firefly larvae.

I went back a few nights later by myself so I could concentrate on photographing some of the things we saw in the marsh the previous night, including the firefly larva. I had no problem relocating one in the same place we found it before (I just turned off my headlamp and waited for the green glow). I’m generally not keen on posting photographs of unidentified insects (just me, but I find photos much more interesting when accompanied by the natural history back story), and I was sure this larva would remain unidentified (I have little knowledge of adult fireflies, much less their larvae). This seemed even more likely after perusing the few identified and many unidentified firefly larvae photographs on BugGuide and finding nothing even remotely similar. I was about to give up when I decided to try the search term “Lampyridae Florida Pinellas” (“Pinellas” being the county where we found the larvae—my thinking being that maybe there was a Florida firefly checklist that could narrow down to the county level the possible species), and high in the results was a page titled Florida intertidal firefly (fiddler crab firefly). On that page was a photo of the larva, although not nearly large and detailed enough to be sure it was the same, but still in my mind almost surely this species because of the stated restricted habitat—intertidal zone of Florida coastal salt marshes! I sent these photographs to lampyroid aficionado Joe Cicero, who kindly confirmed my identification. 

Restricted to intertidal marshes in coastal Florida.

Because it occurs only at the edges of salt water marshes around the peninsular coast of Florida, M. floridana is a classic example of shoestring geographic isolation and, thus, serves as a good model for studies of genetic isolation and its impact on speciation (Lloyd 2001). Along with T. floridana, it now makes at least two rare, Florida-endemics occurring in the small private, preserve behind my sister-in-law’s condominium (both of which were first found as larvae rather than adults). Although the larva of M. floridana is already known—albeit by a rough black and white photograph (McDermott 1954)—it’s rarity and restricted habitat nonetheless make it an exciting find well deserving of the more detailed color photographs shown here. However, as I told Jack after receiving confirmation of its identity, he gets full credit for the discovery. I took him into the field with me with the intention of showing him some new things, and he turned the tables on me! Yes, even a 12-year old can discover the larva of a rare, endemic species!

REFERENCES:

Lloyd, J. E. 2001. On research and entomological education V: a species concept for fireflyers, at the bench and in old fields, and back to the Wisconsian Glacier. Florida Entomologist 84(4):587–601.

McDermott, F. A. 1954. The larva of Micronaspis floridana Green. The Coleopterists Bulletin 8(3/4):59–62.

Copyright © Ted C. MacRae 2012

Planet’s Coolest Critters – Tiger Beetles

/ Ted C. MacRae / 4 Comments

Cicindela scutellaris rugifrons – photo by Harry Zirlin.

Readers of this blog know well (and hopefully share) my affection for tiger beetles (family Cicindelidae). That should come as no surprise, as tiger beetles rank among the most popular of all beetle groups. The reasons for this are many—for me it is their extreme polytopism (geographically based variation in coloration and markings), affinity for extreme habitats, and charismatic behavior (both adults and larvae), while for others it may be from a more basic research perspective (e.g., thermoregulatory behaviors, molecular phylogeny, and visual physiology) or as models for conservation research. I think most, however, will simply declare that tiger beetles are just… well, cool! That is the perspective of Harry Zirlin, who wrote this charming little article entitled, Planet’s Coolest Critters – Tiger Beetles at PetsLady. After introducing the group and its diversity, lifestyles, and behaviors, Harry notes the increasing popularity of tiger beetles with birders, butterfly watchers and nature photography buffs and the recent proliferation of field guides that have enabled their elevation to the ranks of “watchable wildlife.” Maintaining tiger beetles in terraria allows an even closer look at their beauty and behaviors, and Harry gives some useful tips on how best to accomplish this. It’s a pleasant little read, and I recommend you check it out!

Copyright © Ted C. MacRae 2012

Working with Cerceris fumipennis—Epilogue

/ Ted C. MacRae / 10 Comments

Cerceris fumipennis nest littered with Neochlamisus sp. beetles

In Working with Cerceris fumipennis Part 1 and Part 2, I talked about the use of this species as a biosurveillance tool for Buprestidae. These wasps are specialist predators of jewel beetles, which they capture almost exclusively and paralyze with their sting to use as food provisions for their offspring in underground nests. I also mentioned that there are other species of Cerceris, each specializing in its own distinct prey group, and at my site in east-central Missouri I found C. bicornis, a weevil specialist, almost as common as C. fumipennis. Thus, when I came upon this particular Cerceris wasp nest, I wondered it I had encountered yet another species in the genus, for littered around it were case-bearing leaf beetles in the genus Neochlamisus.

The bright coppery coloration suggests Neochlamisus platani

I counted 11 beetles lying on the diggings surrounding this nest, and as is typical with buprestids around C. fumipennis nests these beetles all appeared to represent the same species (I’ve done a little collecting of Neochlamisus beetles in Missouri—the especially bright coppery coloration suggests to me N. platani, a species found on eastern sycamore, Platanus occidentalis). I’ve also noted that C. fumipennis nests littered with beetles on the surface also have beetles—usually of the same species—freshly cached underground, so I decided to dig up the nest to see what might be in it. As I inserted the grass stem and started digging, I heard the distinctive buzzing indicating the wasp was still inside the nest, and when it appeared I noted the distinctive three yellow facial markings that identify it as a female C. fumipennis. As suspected, the nest contained another seven beetles of the same species, and I would later learn that C. fumipennis, while specializing on jewel beetles, does occasionally take other prey. Philip Careless and colleagues recorded two leaf beetles, including Neochlamisus bebbiana, and one weevil as hosts for this wasp at their Working with Cerceris fumipennis website. If my species ID of these beetles is confirmed, this should represent yet another non-buprestid host record for C. fumipennis, although I should also mention that out of several hundred observations this was the only non-buprestid prey I observed around or in a C. fumipennis nest.

Copyright © Ted C. MacRae 2012

Palmetto Tortoise Beetle, Hemisphaerota cyanea

/ Ted C. MacRae / 3 Comments

Hemisphaerota cyanea (palmetto tortoise beetle) on saw palmetto (Serenoa repens)| Levy Co., Florida

While most leaf beetles (family Chrysomelidae) are found associated with herbaceous plant species, many members of the subfamily Hispinae—which includes leaf mining beetles and tortoise beetles—are found on the foliage of woody plants. In North America the most distinctive of tortoise beetles found on trees is the palmetto tortoise beetle, Hemisphaerota cyanea. These distinctive dark blue, hemispherical-shaped (hence, the genus name) beetles with yellow antennae are found in the deep southeastern U.S. on the fronds of saw palmetto, Serenoa repens, and other native and introduced palms. I found the beetles in these photographs near Cedar Key Scrub State Preserve in Levy Co., Florida while searching white sand 2-tracks through sand scrub habitat for the Florida-endemic Cicindelidia scabrosa (Scabrous Tiger Beetle).

Beetles scarify the leaf epidermis, leaving trough-like feeding marks.

I first saw this species during my first insect collecting trip to Florida back in 1986. I didn’t know much then (other than that I really, really enjoyed traveling to different parts of the county to collect insects!). I was in Everglades National Park (with a permit) when I first noticed them dotting saw palmetto fronds. I think I had actually noticed them for some time but thought they were some type of scale insect before eventually realizing it was actually not only a beetle, but a tortoise beetle (one of the many groups of insects in which I was interested during those early, formative days).

Specially modified tarsi and a hemispherical shape allow the beetle to clamp itself tightly against the leaf to repel attack by ants and other insect predators.

I also remember being struck by how difficult it was to pry the adults off of the leaves on which they were sitting. It turns out that these leaf beetles have specially modified tarsi with thousands of bristles tipped with adhesive pads on the undersides. Normally only a few of the pads contact the leaf surface, but when the beetle is threatened it clamps all of them against the leaf and secretes an oil that strengthens the adhesive capabilities of the pads. Thus secured, the beetle clamps its hemispherical-shaped body down tightly against the leaf and is able to resist the efforts of ants and other predators to pry it from the leaf.

Copyright © Ted C. MacRae 2012

One-Shot Wednesday—Proctacanthus fulviventris ovipositing

/ Ted C. MacRae / 14 Comments

Proctacanthus fulviventris | Dixie Co., Florida

Today I spent the day just south of Florida’s “arm pit” to look for the state’s near-endemic tiger beetle Cicindelidia scabrosa (Scabrous Tiger Beetle). I first found this species last August on a white-sand 2-track through sand pine scrub habitat near Cedar Key Scrub State Preserve (Levy Co.). Although I was happy enough with the photographs that I got that day, the small spot of habitat that I found them in had yielded only a few specimens. My goal this time was to find the species in additional localities  to get a better idea of its precise habitat preferences and obtain a better series of specimens that more fully represents the range of variability exhibited by the species in its pubescence, color and elytral markings. By day’s end I would meet this goal, having found the species at four locations in Levy Co. and further north in Dixie Co. My first stop was actually in Dixie Co. near Lower Suwannee National Wildlife Refuge, where I found good numbers of individuals on a white-sand 2-track through pine scrub. A variety of robber flies (family Asilidae) were also seen along the 2-track, but I resisted the urge to photograph them because of the task at hand. Eventually, however, I came upon a female of this rather large species with her abdomen deeply inserted into the loose sand, surely in the act of oviposition. This was too much to pass up, so I set down the net, took off the backpack, and put the camera together. Unfortunately, in the time it took to do this, the fly had already withdrawn her abdomen and was rapidly “sweeping” the tip of the abdomen back and forth over the hole—I presume to cover and hide it. I snapped this first frame (the little bit of motion blur can be seen at the tip of the abdomen), but then I moved carelessly (not my usual habit) when scooting in for a closer shot. This spooked the fly and caused it to fly off, and I was left with this single image.

As much as I like robber flies, I can’t say that I’m well versed in their taxonomy. However, the large size (25–30 mm in length) and overall gestalt suggested to me that it belonged to the nominate subfamily, and cruising through online photographs eventually led me to Proctacanthus fulviventris. The individual seems to agree well with the description of this species provided by Hine (1911), including the bright yellow beard, black femora and red tibiae, and reddish abdominal terga. If my identification is correct, this species—like C. scabrosa—is also a Florida near-endemic whose distribution extends barely into southern Georgia. It’s dark coloration and light brown wings, combined with its large size, surely make it one of the more impressive-looking robber flies, and I’m sorry that I did not attempt to get more photographs of this species while I had the chance, as I did not see it at any of the other locations that I visited on the day.

Incidentally, by my interpretation the scientific name of this species translates to “yellow-bellied spiny-butt”!

REFERENCE:

Hine, J. S. 1911. Robberflies of the genera Promachus and Proctacanthus. Annals of the Entomological Society of America 4(2):153–172.

Copyright © Ted C. MacRae