Super Crop Challenge #16

Who am I?

Who am I?

Can you identify the structures in the photo above (2 pts), their significance (2 pts), and the organism to which it belongs (order, family, genus, and species—2 pts each)? Comments will be held in moderation so everybody has a chance to participate, but there are early-bird bonus points on offer for those who get their answers in quickest. You’ve got the weekend to think about it. 🙂

p.s. Read the full rules for details on how (and how not) to earn points. Good luck!

© Ted C. MacRae 2014

Southern armyworm feeding on soybean

Southern armyworm (Spodoptera eridania) late-instar larva feeding on soybean.

Southern armyworm (Spodoptera eridania) late-instar larva feeding on soybean.

Here is another animated gif that I made recently, this one showing a late-instar larva of southern armyworm (Spodoptera eridania) feeding on soybean (Glycine max). This polyphagous species is widely distributed from the southern U.S. through the northern half of South America and feeds on a variety of weeds, especially pigweed (Amaranthus spp.) and pokeweed (Phytolacca americana). It also occasionally attacks vegetable, fruit, and ornamental crops; however, in recent years it has become increasingly important on cultivated soybean in Brazil and Argentina, especially in regions where cotton is also cultivated. As a result, they have become one of the insects that I deal with regularly in my own research. More information on this and other armyworm species that affect soybean can be found in my earlier post, Quick Guide to Armyworms on Soybean.

Like many other lepidopteran caterpillars that feed on foliage, late-instar larvae become “feeding machines” that remain active both day and night as they try to cram as much nutrition into their expanding bag of a body as possible in preparation for an adult life focused solely on finding mates and laying eggs. Large larvae actively feeding during the day can be rather conspicuous, and as a result they often secrete themselves on the undersides of the leaves while feeding to make themselves less visible to predators. As they feed, however, a “window” opens up that gradually eliminates their cover. Rather than remaining in the same spot and feeding until they are completely exposed, however, larvae will move when the feeding hole reaches a certain size and find another place to conceal themselves before resuming feeding. Different caterpillar species have different exposure tolerances, and as a result, this combines with slight differences also in preferred tissue types to create recognizable differences in the damage patterns resulting from feeding by different species.

For those interested, making these animated gifs is really simple and allows those of us without expensive macro-video gear to simulate short videos of insect behavior. I make my animated gifs at GIFMaker.me—all you do is take a series of photos, touch them up in photo editing software (I use Photoshop Elements to adjust levels, color and sharpness), upload them to the site in the sequence desired, and click “Create Now”. It couldn’t be easier! You don’t even need a “real” camera—I took the photos for this gif with my iPhone using the “burst” function to take a rapid sequence of photos (all you do is hold your finger down on the shutter button for the desired length of time).

© Ted C. MacRae

Digger wasps in action

Bicyrtes quadrifasciatus

Bicyrtes quadrifasciatus digging a burrow | Stoddard Co., Missouri

Here is an animated gif that I made from a series of photographs of the digger wasp, Bicyrtes quadrifasciatus (ID courtesy of Doug Yanega), digging a burrow in a sand bank in extreme southeastern Missouri (it’s amazing what you can do with an iPhone and a free internet app!). A large number of these wasps had colonized the sand bank, and as I photographed this one individual busily digging its burrow, others repeatedly flew up and investigated. The digging individual would disappear briefly down into the burrow, and each time it returned to the surface with a fresh load of sand another wasp would fly up to it and investigate. The digging individual never seemed to pay much attention to the investigating wasp, so I’m not sure if these other wasps were looking for a potential mate or perhaps even trying to usurp the burrow.

The cumulative noise from all of the flying wasps was really quite remarkable—indeed, the noise is what drew my attention to the sand bank in the first place. A video of the colony with my commentary can be seen here. I did see one wasp that had returned to its burrow carrying prey (apparently a stink bug in the family Pentatomidae). I touched the wasp thinking that it would drop the prey and fly away, as another digger wasp, Cerceris fumipennis, does with its buprestid prey when disturbed. This would have given me a chance to confirm the prey identity. Unfortunately, the wasp kept hold of the prey and flew off with it.

© Ted C. MacRae 2014

Pretty, little, no-name spider

I don’t like posting photographs of unidentified “bugs” (insects, spiders, etc.). There are times, however, when my best efforts are thwarted and I’m left with the choice to admit defeat or relegate the photos indefinitely to the “archives”. In this case, the subject in the photos is just cute to hide. I found this bright red spider on the blossom of a flowering dogwood (Cornus florida) this past spring while hiking the North Fork Section of the Ozark Trail near Blue Hole Hollow in Howell Co., Missouri. While I am fairly certain that it belongs to the family Linyphiidae (dwarf and sheetweb spiders), I cannot decide if it is the former or the latter. Among the dwarf spiders (subfamily Erigoninae), it resembles some members of the genus Ceraticelus, while among the sheetweb spiders (subfamily Linyphiidae) it seems a good match for the genus Florinda (as suggested by Bug Eric). Whatever its identity, it is one of the prettiest and most brightly colored little spiders I have seen. (Photographed on 4 May 2014 with a Canon MP-E 65 mm 1-5X lens.)

Edit 8/22/14, 12:20 p.m.—I now believe this to be an orb weaver (family Araneidae), albeit a very small one (only ~8 mm in length); specifically something in the genus Hypsosinga. Take a look at this photo of H. rubens, which seems to be a near perfect match for the individual in these photos.

Ceraticelus minutus?Ceraticelus minutus? Ceraticelus minutus? Ceraticelus minutus? Ceraticelus minutus?

© Ted C. MacRae 2014

Stag and “stagette” beetle

Lucanus capreolus, female (L) and male (R) | Fort Defiance Park, Illinois

Lucanus capreolus, female (L) and male (R) | Fort Defiance Park, Illinois

Last month I posted some photos of the very “stag beetle-ish” looking longhorned beetle, Parandra polita. Chestnut brown in color with large, forward projecting mandibles, this member of the longhorned beetle subfamily Parandrinae looks almost nothing like longhorned beetles in other subfamilies but very much like a small species of stag beetle (family Lucanidae). If it weren’t for the straight rather than elbowed antennae, even experienced coleopterists might be fooled by its appearance. The beetle had been attracted to an ultraviolet light setup in wet bottomland forest at the southern tip of Illinois where the Mississippi and Ohio Rivers meet. Perhaps not coincidentally, several true stag beetles representing both males and females of the species Lucanus capreolus were attracted to the lights that night as well.

Males are distinctive by their large, sickle-shaped mandibles.

Males are distinctive by their large, sickle-shaped mandibles.

The genus Lucanus contains the largest stag beetles in North America—the most desirable of the handful of species it contains being L. elaphus (North America’s largest stag beetle) due to the male’s outrageously enlarged mandibles and the species’ general scarcity. Lucanus capreolus nearly matches L. elaphus in size and has an equally broad distribution across eastern North America, but it seems to be a more common species and has the male mandibles only moderately (though still distinctly) larger than the female. Despite its more routine occurrence, I rarely see more than a few individuals at a time, and they are almost always all males. This night, however, I was fortunate to encounter not only males but several females as well. I’ve previously photographed the female of this species (Diminishing Stag Beetle), but this was my first chance to photograph both male and female together.

Females have much smaller mandibles (but are still capable of delivering a painful 'nip').

Females have much smaller mandibles (but are still capable of delivering a painful ‘nip’).

While male L. elaphus are undeniably distinct, I frequently see confusion about how to distinguish male L. capreolus from L. placidus (the third eastern North American species of the genus, occurring more sporadically than L. capreolus), and separating females of all three species can be even more confusing. Male L. elaphus are readily identified by their greatly elongated and multi-toothed mandibles, but a suite of characters may need to be employed for females and non-elaphus males. The best character to use for L. capreolus are the distinctly bicolored femora that are yellowish at the base; however, color can be variable and some individuals will exhibit the more uniform chestnut-brown color typical of L. elaphusLucanus placidus, on the other hand, is usually distinctly darker in color than either of the other two species. Surface sculpture of the elytra and pronotum also offer useful characters. The elytra of L. capreolus and L. elaphus are rather smooth, while in L. placidus they are more distinctly punctate/rugose. The pronotum of both L. capreolus and L. placidus, however, is usually distinctly punctate compared to the relatively smooth pronotum of L. elaphus. The shape of the labrum (projection between the mandibles) is also usually distinctive and is not influenced by gender like the mandibles. In L. elaphus the labrum is rather pointed, while in L. capreolus and L. placidus it is more blunt (indeed, in L. placidus the labrum can almost be described as quadrate, or “squared”). Lastly, the number of teeth on the inner margin of the mandibles is usually diagnostic for females of the three species—L. capreolus possessing one tooth, L. placidus possessing two, and L. elaphus possessing more than two.

Unlike in most insect groups, males rather than females.

Unlike most insect groups, male stag beetles rather than females are generally larger.

© Ted C. MacRae 2014

A time of reckoning

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

The Buprestis tree

After collecting Chrysobothris seminole at the type locality in Georgia and Chrysobothris orono the following day at South Cumberland State Park in Tennessee, I thought my trip last May with fellow buprestophiles Josh Basham and Nadeer Youseff was a complete success. I had collected two species of jewel beetles (family Buprestidae) that I had never collected before—not an easy thing for me to do in the eastern U.S. now after three decades of collecting, but little did I know that I would go on to collect three additional such species that same day. We had only seen two C. orono individuals after a fair bit of searching on the exposed roots of the Virginia pines (Pinus virginiana) growing along the blufftops, but I’ve learned to be tenacious and not give up too quickly when searching for rare species.

Virginia pine (Pinus viriginiana) on bluff tops | South Cumberland State Park

Virginia pine (Pinus viriginiana) on bluff tops | South Cumberland State Park, Tennessee.

During my searches, I gave a lot of attention to one particular tree at the far end of the bluff—though it was alive and not showing any outward signs of distress, there was just something about it that made me think, “that’s a buprestid tree.” I don’t know if it was the sparsely limbed crown, the relatively smooth trunk with one side fully exposed to the sun, or just its lonely position at the edge of the bluff away from other trees (regretfully, I did not photograph the tree). At any rate, I checked it over every time I wandered down to that end of the bluff. During one of my inspections, I mentioned to Josh that I thought this tree looked good for buprestids, and as I did my eyes suddenly noticed a large individual in the genus Buprestis sitting on the trunk right in front of me. I grabbed it and yelled out to Josh what I’d found—I recognized it as a member of the subgenus Cypriacis but wasn’t sure about the species. Josh came over to take a look and immediately recognized it as B. strata. He mentioned that this was one of several other species besides C. orono that he and Nadeer have found before at this site. I told Josh that this was yet another species I’d never collected before (although I do have a specimen in my collection received in trade). The photos below were taken later that evening in the safety of the studio with the beetle on a piece of Virginia pine bark. This species is recognizable as a member of the subgenus Cypriacis by the elytra with alternate intervals depressed and heavily punctate, giving the beetle a strongly ribbed appearance—there are a few other species in this subgenus in northern and western North America.

Buprestis (Cypriacis) striata  | South Cumberland State Park, Tennessee

Buprestis (Cypriacis) striata | South Cumberland State Park, Tennessee

Buprestis (Cypriacis) striata  | South Cumberland State Park, Tennessee

Buprestis (Cypriacis) striata | South Cumberland State Park, Tennessee

Buprestis (Cypriacis) striata  | South Cumberland State Park, Tennessee

Buprestis (Cypriacis) striata | South Cumberland State Park, Tennessee

This find fueled another hour or so of continued searching of the pines, now not only for C. orono, but also for B. striata. As we continued to search, I queried Josh about the other species he had collected here. One that he mentioned that got my attention was Buprestis salisburyensis. I mentioned that not only had I never collected that species either, but that I’d never even seen it. Eventually I asked him what it looked like, and he went on to describe what sounded to me like an incredibly beautiful species—brilliant, metallic blue-green with bright red around the edges of the elytra. As he described the species, I began walking back towards the tree, and immediately I saw one sitting on the rock at the base of the tree. I yelled out, “There’s one!”, crept up slowly, and clamped my net over it (all of which was probably unnecessary—most Buprestis species are rather clumsy and easy to capture, unlike the comparatively zippy Chrysobothris). The photos shown here, like those of B. striata, were also taken later that evening indoors—even though I had found the beetle sitting on the rocks at the base of the tree I thought it would look more natural on Virginia pine bark. I also photographed the beetle on a needle clump, as this and other members of the subgenus Stereosa (recognizable by the large punctures of the elytra) have been beaten from needles of young. healthy pines (Helfer 1941). This makes perfect sense to me, given their coloration which could actually serve a cryptic function.

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

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

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

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

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

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

I mentioned a third species that I collected for the first time that day—after finishing at South Cumberland State Park, Josh took me to a spot where he had collected North America’s only coraebine buprestid, Eupristocerus cogitans. This species breeds in alder, and there was a sickly clump of alder trees next to a small lake. I looked at the tree, stuck my beating sheet under a branch and gave it a whack—there sat two individuals! I moved the sheet under another branch, gave it a whack, and there sat two more individuals! In my excitement of having collected this species for the first time (and my zeal to get even more), I completely forgot about making sure the vial I placed them in was not charged with ethyl acetate so that I could take photos later on. When I finally realized my mistake it was too late—the specimens were dead. I suppose I could have placed one on a branch and photographed it anyway, but with live individuals of Chrysobothris oronoBuprestis striata, and B. salisburyensis already in queue for photographs I opted to hope for a second chance someday.

REFERENCE:

Helfer, J. R. 1941. A revision of the genus Buprestis of North America north of Mexico (Coleoptera, Buprestidae). Entomologica Americana 21(3):123–199.

© Ted C. MacRae 2014

Proof that it’s possible to ship large, pinned beetles safely!

Miscellaneous Buprestidae from Dan Heffern

Miscellaneous Buprestidae from Dan Heffern

Those who have followed this blog for awhile know that I’ve been on a bit of a rant during the past few months about the way pinned insect specimens are packed and shipped. This has been prompted primarily by the receipt of several damaged insect shipments, some of the more egregious examples of which are shown here and on Facebook. In all of these cases, damage could have been prevented had the specimens simply been packed and shipped using standard best practices.

I do not wish, however, to give the impression that every insect shipment I receive is damaged. The photo above represents a shipment I just received from Dan Heffern, who is kindly gifting to me some of the excess Buprestidae that he has in his collection in order to make room for his more beloved Cerambycidae. This shipment was especially prone to damage because of the number of large, heavy-bodied specimens it contains. Nevertheless, it arrived safe and sound because of the attention paid by Dan to securing the specimens in place. Note the liberal use of brace pins around each specimen—the larger the specimen, the more brace pins. In addition, the pinning box features a double-foam layer. Double-foam holds specimens much more securely in place than does a single layer, and while I didn’t mention it in my original post it’s a good idea for shipments containing large, heavy-bodied specimens. One drawback of double-foam is that it pushes labels on the pin up close to the specimen, but re-positioning labels on pins is certainly better than having to reattach broken body parts on specimens!

My thanks to Dan for this fine shipment and for paying such great attention to its packing to ensure receipt in the best condition possible!

© Ted C. MacRae 2014