Month: November 2012

Another autumn oedipodine

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Shortgrass/sage brushland habitat in Medicine Bow Natl. Forest, Wyoming

In September 2010, Chris Brown and I explored shortgrass/sage brushland habitat atop the Laramie Mountains in southeastern Wyoming’s Medicine Bow National Forest (location “J” on this map). We were entering the final days of our 7th Annual Fall Tiger Beetle Trip™ and, to that point, had found every tiger beetle species we had set out to look for. This day, however, was the official “skunk” day of the trip, for although we did see one Cicindela limbalis (Common Claybank Tiger Beetle)—collected live to become the subject of one of the crappiest tiger beetle photos I’ve ever taken—we did not see the tiger beetle that we were there to see; Cicindela longilabris (Boreal Long-lipped Tiger Beetle). Of course, I rarely have trouble finding consolation on a skunk day, and during fall this is even easier—the deep blue sky, crisp fall air, and vivid colors of a morphing landscape are enough to make even a bad day of insect collecting better than a good day of just about anything else. And then there are the band-winged grasshoppers (family Acrididae, subfamily Oedipodinae)!  When there are no tiger beetles to be had, there are almost always members of this group around, and other than tiger beetles I don’t think there is another group of insects that I enjoy photographing more.

Arphia pseudonietana (red-winged grasshopper) | Medicine Bow Natl. Forest, Wyoming

As we walked the trails not finding tiger beetles, I noticed these very dark grasshoppers every once in a while. They flew with a particularly noisy crackling sound that exposed bright red hind wings before dropping to the ground and instantaneously becoming almost completely invisible. Once I accepted that tiger beetle photography just wasn’t gonna happen that day, I began paying attention to these grasshoppers and, after working a few individuals, finally found one who was willing to let me get close enough for some photos. I’m not terribly fond of this first photo—the perspective is still too high as I had not yet learned by that time to get down flat on my belly for photographing anything on the ground (remember, this was two years ago). Nevertheless, it is the only one that I have that shows the entire body of the grasshopper. Since this location isn’t too far west of the Nebraska border, I figured an identification should be possible using the Nebraska grasshopper guide (Brust et al. 2008)—based on that work and subsequent examination of photos at BugGuide, I surmise this individual represents Arphia pseudonietana (red-winged grasshopper). There are other species of Arphia in Nebraska, some of which are easily confused with A. pseudonietana; however, most of these are more common further east. The only other species in the genus that occurs west into Wyoming is A. conspersa (speckle-winged grasshopper), and although it is similar in appearance and may have red hind wings (though more commonly orange to yellowish), adults are most common during spring and early summer. Arphia pseudonietana adults, on the other hand, are most active during mid-summer through fall.

The pronotum bears a single notch just in front of the middle.

Grasshoppers, particularly in the western states, tend to be loathed by ranchers who see them as competitors with cattle for meager forage resources, especially in dry years. This species does feed preferentially on a variety of grasses such as western wheatgrass (Pascopyrum smithii), buffalograss (Buchloe dactyloides) and blue grama (Bouteloua gracilis); however, it doesn’t seem to occur at economically important levels except in association with other, more numerous grasshopper species. I’m glad to know this, because for some reason I just don’t want anybody regarding band-winged grasshoppers of any kind as a pest. Other grasshoppers, fine—just not my beloved bandwings!

I presume this 5th instar nymph also represents A. pseudonietana

Later in the day I came across this presumed 5th-instar grasshopper nymph, and although it was quite skittish I eventually managed to get this single photograph before it resumed its frenetic hopping and I gave up in frustration. This is one of the better “one-shots” that I’ve managed to take—my only criticism being that the focus was just a tad too deep to catch the front metafemoral face. I really didn’t have much time to setup for this shot—once I got the critter reasonably in-frame I fired! Anyway, I’m inclined to think this also represents A. pseudonietana, although I’m less confident in that ID than I am for the adult as I wasn’t able to find a real good comparative photograph. Nymphs of A. pseudonietana are apparently most common from mid-spring to mid summer, so the seasonality is a bit off. I would be grateful to any acridophile who stumbles across this post and can provide an ID confirmation or correction (for either the nymph or the adult). Until then, I leave you with a shot that shows why I love fall regardless of whether I’m finding insects!

Quaking aspen glows under the late September sun.

REFERENCE:

Brust, M. L., W. W. Hoback and R. J. Wright.  2008. The Grasshoppers (Orthoptera: Acrididae and Romaleidae) of Nebraska.  University of Nebraksa-Lincoln Extension, 138 pp.

Copyright © Ted C. MacRae 2012

Mother and daughter (perhaps)

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Phrynus marginenotata (Florida tailless whip scorpion)

Back in May I visited the California Department of Food and Agriculture’s Plant Pest Diagnostics Laboratory in Sacramento. While I was there to visit my friend and colleague Chuck Bellamy and see him receive Honorary Membership in The Coleopterists Society, I was also anxious for the opportunity to spend time with the lab’s other entomologists—most of whom I interact with as members of the Editorial Board of The Pan-Pacific Entomologist. Among the more ‘colorful’ of these is Martin Hauser, a dipterist (although I don’t hold that against him!) who also has a passion for maintaining live, captive arthropods. For me, there is nothing finer than visiting the lab/office of a taxonomic entomologist—one wall lined with steel cabinets full of insect specimens, another wall crammed-full of books and literature (the older the better), a workbench with microscope at the center of a jumble of specimen containers and open reprints, and shipping boxes piled everywhere. I take that back—there is nothing finer than visiting the lab/office of a taxonomic entomologist that also keeps livestock! Martin’s collection of live arthropods, however, goes well beyond the requisite 10-gallon aquarium with Madagascan hissing cockroaches. I already featured one of his more unusual tenants, Damon diadema (Tanzanian giant tailless whip scorpion), and here I feature its North American relative, Phrynus marginenotata (Florida tailless whip scorpion).

The genus is characterized by five spines on the pedipalp tibia—the 3rd shorter than the 2nd and 4th.

According to Weygoldt (2000), this is the northernmost and only U.S. representative of a mostly northern Neotropical genus of eleven species, recognized by the pedipalp tibia (the thickened segment of their “claws”) with five spines—the middle one shorter than the 2nd and 4th (refer to Photo 2). This species occurs in southern Florida and some Antillean islands, where it lives under coral stones and rocks close to the beach—a habitat that presumably subjects them to periodic flooding. While most tailless whip scorpions prefer humid/moist environments, they nevertheless studiously avoid standing water itself. This species, however, has been observed to voluntarily enter the water when placed on a stone surrounded by water and remain submerged for as many as eight hours. Remarkably, submerged individuals remain active and do not drown, apparently the result of a “plastron”—an area of the cuticle surrounding the lung openings that is packed with stiff, branched structures and, thus, capable of holding a volume of air against the body while the animal is submerged. The plastron seems to function much like a gill—oxygen continuously diffuses into the plastron from the surrounding water as it is used for respiration.

The bright orange pedipalps of 2nd-instar nymphs contrast with the somber coloration of the adults.

Like the D. diadema individuals that I also photographed, these P. marginenotata individuals had also produced viable eggs which had hatched a few weeks before my visit. Two nymphs can be seen with the adult in the top photo (although I can’t say for sure whether the adult is actually the mother), and Photos 3 and 4 show one of these nymphs up close and personal. I would have liked to have seen these nymphs when they first hatched, as the 1st-instars are a soft sea-green color and remain clustered on their mother’s abdomen until they are able to start fending for themselves (for a beautiful photo showing this, see Piotr Naskrecki’s The scariest animal that will never hurt you). The 2nd-instars that I photographed had already left their mother, and while they had lost their sea-green coloration, their pale yellow/gray bodies and bright orange pedipalps were no less striking compared to the more somber coloration of the full-sized adults.

…and, of course, the signature BitB face shot!

REFERENCE:

Weygoldt, P. 2000. Whip Spiders (Chelicerata: Amblypygi): Their Biology, Morphology and Systematics. Apollo Books, Stenstrup, Denmark, 163 pp.

Copyright © Ted C. MacRae 2012

Where siblings mingle: Ellipsoptera marginata vs. E. hamata

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When Erwin & Pearson (2008) formally broke up the great genus Cicindela by elevating most of its former subgenera to full genus rank, it caused a bit of consternation amongst some North American cicindelophiles. The argument went something like, “Now we have all these new genus names to learn, and we’ll have to relabel and reorganize everything in our collections, and how do we know the names won’t change again, and we can’t even tell them apart in the field anyway, and blah blah…” Pardon me, but since when did taxonomy become more about slotting species into fixed, easy-to-learn categories and less about best reflecting dynamic knowledge of complex evolutionary relationships? In the case of Cicindela and its former subgenera, however, even these arguments don’t hold up to close scrutiny—tiger beetle enthusiasts in North America should have already been quite familiar with the former subgenera due to their inclusion in the widely accepted Pearson et al. (2006) field guide, many of which actually do present a unique suite of morphological/ecological characters that facilitate their recognition in the field, and I personally find that nomenclatural recognition of individual lineages helps my attempts to learn and understand them much more than dumping them into a large, all-encompassing genus based on superficial resemblance. As for insisting that names don’t change, well that has never been a tenet of taxonomy. Stable, yes, but fixed and immutable, no.

Ellipsoptera marginata male | Pinellas Co., Florida

Enough waxing philosophic. One of the more distinctive of the former subgenera is Ellipsoptera. Morphologically the genus is defined by details of male genitalia, but the 11 North American species are generally recognizable in the field by their relatively “bug-eyed” look and long legs (Pearson et al. 2006) and, as a group, seem ecologically tied to extreme habitats with sandy and/or saline substrates that are nearly or completely devoid of vegetation. Coastal marshes and mudflats, saline flats, sandy river banks, and deep sand ridges representing ancient coastlines are some of the habitats where species in this genus are most commonly encountered. Most of the species exhibit a fairly uniform facies but differ in the details of maculation and dorsal coloration, but two species that stand apart from the rest are E. marginata (Margined Tiger Beetle) and E. hamata (Coastal Tiger Beetle) due to the highly diffuse middle band of their elytra. These are both eastern coastal species and presumably represent sibling species that have diverged based on geographical range partitioning—E. marginata along the Atlantic Coast and E. hamata along the Gulf Coast. In the field, the two species are almost identical in appearance but nonetheless easily identifiable based on geographical occurrence. There is, however, a small stretch of coastline—the lower Gulf Coast of Florida—where the ranges of the two species overlap and geography alone isn’t sufficient for species determination.

Ellipsoptera hamata lacerata male | Dixie Co., Florida

Fortunately, despite their strong resemblance to each other, field identifications in areas where these species co-occur are still possible due to the presence of small but distinct sexual characters present in one species but absent in the other. Close examination is necessary to see the characters (or their absence), so it is best to net a few individuals and examine them in the hand or, as I have done here, look at them through the viewfinder of a camera. The photos in this post include the male and the female of both species, each showing the presence or absence of the distinguishing character.

Ellipsoptera marginata female | Dixie Co., Florida

In most tiger beetles, male individuals are distinguished by a number of secondary sex characters, but easiest to see in the field are the brush-like pads on the underside of the front tarsi (“feet”). Males of E. marginata and E. hamata are further distinguished from each other by the presence (E. marginata) or absence (E. hamata) of a distinct tooth on the underside of the right mandible. Photo 1 above shows a male E. marginata from Pinellas Co., Florida, and the tooth is easily seen in that relatively distant view. Photo 2 above shows a male E. hamata lacerata (Gulf Coast Tiger Beetle)—the Floridian subspecies, and while a small bump can be seen on the underside of the right mandible, it is not nearly as well developed into a distinct tooth as in E. marginata.

Ellipsoptera hamata lacerata female | Dixie Co., Florida

Female tiger beetles, on the other hand, lack the brush-like tarsal pads present in the males and are further distinguished by the “mesopleural coupling sulcus”—an area just behind the side of the pronotum that receives the male mandible during mating and is thus devoid of setae (compare the females in Photos 3 and 4 with the males in Photos 1 and 2). Neither E. marginata nor E. hamata females possess the mandibular tooth found in E. marginata males, but they can be distinguished from each other by their elytral apices. In E. marginata females (Photo 3), the elytra are curiously “bent” at the tips, forming a distinct indentation at the apex of the elytra where they meet, while female E. hamata (Photo 4) lack this indentation.

Are there other tiger beetle sibling species groups for which you would like to see comparative posts such as this one?

p.s. I completely neglected to mark yesterday’s 5th anniversary of Beetles in the Bush! I don’t know how I missed a milestone as big as five years—hopefully my ability to provide interesting content is faring better than my middle-aged memory!

REFERENCES:

Erwin, T. L. and D. L. Pearson. 2008. A Treatise on the Western Hemisphere Caraboidea (Coleoptera). Their classification, distributions, and ways of life. Volume II (Carabidae-Nebriiformes 2-Cicindelitae). Pensoft Series Faunistica 84. Pensoft Publishers, Sofia, 400 pp.

Pearson, D. L., C. B. Knisley and C. J. Kazilek. 2006. A Field Guide to the Tiger Beetles of the United States and Canada. Oxford University Press, New York, 227 pp.

Copyright © Ted C. MacRae 2012

Araneus marmoreus encore

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Araneus marmoreus adult female—ventral view showing epigyne.

Here is the full-sized photo from which the crop shown in Super Crop Challenge #14 was taken. The small finger-like structure in the upper right of the photo—the object of the challenge—is the epigyne (or epigynum) of Araneus marmoreus (marbled orb weaver spider). Spiders have a rather unusual mating strategy—rather than possessing genitalia that couple for insemination, male spiders first form a packet of sperm (spermatophore) and transfer the packet to an enlarged segment (tarsus) at the end of their pedipalps. During mating, the male inserts the tarsus into the female genital opening, thereby effecting sperm transfer. The female genital opening and associated structures, located on the underside near the front of the abdomen, are called the epigyne and function to direct the male pedipalps during sperm transfer. The shape of the epigyne varies greatly and uniquely among species—probably serving as an isolating mechanism that prevents interspecific mating and also providing a good diagnostic character for species recognition among even very closely related species (similarly to the hardened male genitalia of many insect groups). An even closer view of the epigyne of A. marmoreus can be seen in this BugGuide photo.

Araneus marmoreus (marbled orb weaver) | Washington Co., Missouri

This is actually the second time I’ve featured A. marmoreus in a quiz—the intricate pattern of the dorsal abdomen being the subject of Super Crop Challenge #2. Folks had an easier time identifying the critter in that challenge than this one, which I guess is not surprising since people tend to know animals more by their color patterns than the structures of their genitalic openings. As in that first challenge, I encountered this adult female during a hike along the Ozark Trail, this time in Washington County in east-central Missouri. Unlike before, however, I found this spider crawling on a fallen log in the dark forest floor rather than resting in her web. The colors of this species are diverse and spectacular—a recipe that makes them almost irresistible to insect macrophotographers. That this is true is demonstrated by the 360! photos of this species posted to BugGuide.

Hot orange and yellows glow against the dark, moist wood of a fallen tree trunk.

While my previous photos of this species were colorful, these simply glow due to the more orange coloration of this individual and its contrast with the darkened color of the moist wood. It’s a November color scheme if there ever was one—appropriate since I took them exactly one year ago today on November 23, 2011. She was a lot more cooperative than the first subject, and because of this and the stable substrate on which she was sitting I was able to get my favorite shot of all—the face portrait! Not quite as endearing as a jumping spider face (with its large, anthropomorphic median eyes), but striking nevertheless.

The obligatory BitB face shot!

A word about the challenges—I’m not sure if the lack of response to this one is an indication of difficulty or further evidence of declining relevance of blogs as an interactive social medium. I can’t help but notice that blog commenting in general has dropped with the rise of more functionally interactive media such as Twitter and Google+. What do you think—was this challenge too hard, or has the concept of challenge posts lost its appeal?

Copyright © Ted C. MacRae 2012

Super Crop Challenge #14

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Wow, has it really been five months since the last Super Crop Challenge?! Well, it’s time to start a new BitB Challenge Session (this will be #7), so what better way to start? Can you name the structure shown in the photo below (2 pts), the organism to which it belongs (order, family, genus, and species—2 pts each), and its significance (2 pts)?

Note: If you are not completely familiar with them, please read the full rules for details on how and how not to earn points. Good luck!

Copyright © Ted C. MacRae 2012

Great Smoky Mountains National Park

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Is there any question why these are called the Smoky Mountains?

Last week I attended the Entomological Society of America (ESA) meetings in Knoxville, Tennessee. It was my first ESA attendance in more than ten years, so I took full advantage of the opportunity by speaking at the insect macrophotography symposium, presenting a poster on my soybean insect research, and enjoying face-to-face conversations with an extraordinary number of colleagues—some of whom I had not seen since my last ESA meeting and many more for which this was my first opportunity to meet them in person. I admit to having grown a little complacent in recent years about the importance of regular personal contact in cultivating these relationships—my attendance at this year’s ESA reminded me of that fact, and I’ve renewed my commitment to make ESA attendance a priority in the coming years.

Of course, no meeting should be all work and no play, and for me the chance to sample the local natural or cultural history is an added benefit of meeting attendance. This year’s destination for such was a no-brainer—located less than an hour’s drive from Knoxville, Great Smoky Mountains National Park is the largest federally protected area east of the Mississippi River. Straddling some of the highest peaks of one of the world’s oldest mountain ranges, the park has been designated an International Biosphere Reserve by the United Nations due to its rich biota.

One afternoon is not nearly enough time to even scratch the surface of the park’s 800 square miles, but it’s enough to get a taste of the diverse habitats they encompass and whet the appetite for further exploration. Highly recommended for those short on time is Clingman’s Dome—the park’s highest point at 6,643 ft. An observation tower allows spectacular vistas (provided the day has good visibility) of the surrounding mountains and the evergreen forests that cloak them. Unfortunately, the view has been marred in recent years by the accidental introduction of an exotic woolly adelgid (a relative of aphids) from Europe and its subsequent establishment on the forest’s Frazier firs. Dead trunks rise from the forest like tombstones—ghostly reminders of what has been lost. The starkness of the high elevation forest contrasts with the lush mixed hemlock forest that dominates the park’s lower elevations, and the 2.4-mile Alum Creek Trail provides an intimate experience with this rich forest and its thick understory of native rhododendron. I hope the following slide show imparts some essence of the experience, and larger versions of each photo can be seen by clicking on the thumbnails in the gallery that follows.

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Copyright © Ted C. MacRae 2012

It’s a Mayfly…It’s a Moth…It’s Thyridopteryx

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Mississippi River @ Hwy 62 bridge

One of the nice things about the study of insects is the endless opportunity for discovery. It could be a new species, or it might just be something already known but not yet seen personally. I’ve been collecting insects most of my life, and although much of it has been done in far away places the bulk has occurred in my home state of Missouri. Despite my long experience in this state, this past summer I had the opportunity to experience collecting within the state in a way that I’ve not yet done before—blacklighting up and down the length of the Mississippi River regularly during the months of July through September. Each time, I would arrive at the selected spot in the early evening while there was still daylight and search the (hopefully sandy) beaches for evidence of several tiger beetle species that might occur in such habitat. Then, as the sky turned aglow from the setting sun, I would setup the blacklights and wait for the appearance of those particular tiger beetles that are attracted to such.

Thyridopteryx ephemeraeformis | Mississippi Co., Missouri

Expectedly, beetles were seen at only some sites, and numbers and diversity generally decreased as summer approached its end. By early September beetles were no longer showing up even though the habitat seemed good (I guess that’s why they call them “summer” species). Still, on this particular night, the lights setup at the Hwy 62 bridge in far southeastern Missouri were attracting a variety of other insects, so I kept them on to see what might come in. I had nothing else to do. At some point, I noticed a strange insect that seemed like a cross between a mayfly and a moth, and then another…and another. Although I had never seen one of these in person before, I knew exactly what they were—male bagworms! Bagworms (order Lepidoptera, family Psychidae), of course, are extraordinarily common in Missouri, and the sight of dozens or even hundreds of their silken/twig bags attached to ornamental evergreen shrubs in the neighborhood where I lived as a kid remains vivid. I can remember “popping” the larvae inside to see their innards ooze out from the tip of the bag (I know—I’m not proud of it) and even cut open a few of the bags to see the larvae inside (that is, once the less sadistic and more scientifically curious side of me took over). Despite all of this, I had never seen an adult bagworm—male or female—until this night.

Dorsal view

Obviously, these are males because they have wings—females remain wingless into adulthood and, in fact, never even leave the bag in which they’ve spent their entire lives. Bagworm males are distinctive in that their wings are virtually devoid of any scales, and I surmise that the generic name of the most common species in eastern North America—Thyridopteryx ephemeraeformis—is derived from the Greek thyris (window) and the Latin ptera (wing) in reference to this. I was fascinated by the strange appearance of these moths and even more fascinated by the curious manner in which the males held out the tip of their abdomen when at rest; reminiscent of a female releasing sex pheromone. This can’t be true, because it is the females that call from their bags to attract the males, and since the females remain within their bag, the male must insert his abdomen through the tip of the bag and all the way to the top where he can reach the female genital opening. Thus, the male abdomen is highly extensible and prehensile—I guess the males can’t keep an abdomen with that much stretching capacity still for very long.

Two males

Based on gestalt, I presumed these represented T. ephemeraeformis since it is such a common and widespread species, but it’s not always wise to presume, especially in a relatively more southern location. The Moth Photographers Group lists five species in this genus in North America, two of which (T. alcora and T. meadii) seem to be southwestern in distribution. Of the remaining three, T. ephaemeraeformis is the only one I could find any photos or information beyond simple listings (the Moth Photographers Group lists no distribution records for T. rileyi or T. davidsoni), so I asked my lepidopterist friend Phil Koenig for his opinion. Phil informed me that T. ephemeraeformis has been recorded in Missouri 285 times in 49 counties, while T. rileyi is known from the state based only very old literature records and T. davidsoni not at all. Thus, the odds are definitely favor these males representing T. ephemeraeformis. Late summer is apparently the prime period of adult bagworm activity. I’ve not done much blacklighting late in the season because most of the beetles on which I’ve focused over the years and that are attracted to blacklights are active more during spring and early summer. This could explain why I’ve not until now seen male bagworms despite their commonness in Missouri.

Copyright © Ted C. MacRae 2012

Approaching the unapproachable

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Yesterday I gave a talk at the Entomological Society of America’s Insect Macrophotography Symposium, focusing on techniques that I use for photographing wary insects in the field. Turnout for the symposium was awesome (I estimate ~125 people in attendance), and as the first talk I’ve given where I presented myself as a photographer I was pleased at the warm reception I got. A big thanks to my friends and colleagues who showed up to see the talk—it was great seeing your friendly faces in the crowd.

For those of you who couldn’t attend the ESA meetings this year or were unable to see my talk, I’ve attached a PDF version of the talk to this post—click on the image of the title slide below to see it. I expect I might give some version of this talk again in the future, so I would love to hear about any techniques you have found useful for approaching and photographing wary, skittish insects in their native habitats.

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Copyright © Ted C. MacRae 2012