nature

They’re baaaaack… finally!

/ Ted C. MacRae / 21 Comments

For almost a month I waited—waited for that spaceship-sounding drone from the trees; waited for their bodies to drip from the vegetation and their skins to litter the yard; waited for their delightful shrieks every time I jostle a tree branch. I had seen them mass emerging from the ground in southern Missouri in late April, but just 100 miles north in my hometown it seemed they would never show. Cold, rainy springs must not be to their liking, as it was not until the sun finally broke through and temperatures climbed into the 80s that they finally made their appearance in St. Louis—nearly a month after that mass emergence event further south had me looking and listening daily for one of North America’s most spectacular natural history events, Brood XIX of the periodical cicada!

Finally, on May 21 I saw the first adults of the year at Shaw Nature Reserve not too far from my house (not intending to claim this as the date of their first appearance in my area!). They were not yet singing, but the adults were everywhere, many sitting right next to the skins they had just emerged from the previous evening. I had to travel on business through the southeastern U.S. that following week, and it was while visiting the beautiful MSU campus in Starkville, MS that I got my first taste of their late-afternoon synchronized, pulsating song. Upon my return to St. Louis at the end of the week, the eery drone filled the air as soon as I stepped out of the airport. It had been 13 years since I’d heard that sound, but euphoric recall instantly transported me back to 1998 and 1985 and my experiences with these marvels of evolution.

I don’t know that there is anything I can say about the periodical cicada that hasn’t already been said—repeatedly—by the numerous, more erudite sources that are following this event as if it were the approach of Haley’s comet. I don’t even know for sure which species are in my area and how to tell them apart. All I do know is that the constant droning of their singing is both maddening and amazing—a spectacle to behold for what it is, knowing that it will be the year 2024 before I have my next chance to witness it.

As I write this, I’m sitting in my hotel room in Salem, AR, where the cicadas are even more abundant than around my home in the woods—several stops to check building lights for beetles have ended in frustration because the cicadas were so numerous that they virtually swamped the space on the walls under the lights. There do seem to be two species here—a smaller one with a completely dark underside and the raspy, screeching sound that I am familiar with, and a larger one with the abdominal segments light along the posterior margins and a softer trill that almost reminds me of the song of an American toad. Maybe there are other species mixed in that I have not discerned, but I’ll not concern myself with that. Instead, I will continue to marvel at the extraordinary event unfolding before me, watch it as it cycles out, and chuckle at the complaints of the masses bemoaning their temporary inconveniences.

Copyright © Ted C. MacRae 2011

Wrong lens

/ Ted C. MacRae / 12 Comments

During the past couple of years, as I’ve transitioned from strictly a net-wielding entomologist to one that also carries a camera, I’ve had to start making choices about whether to keep the camera in the backpack or hold it at the ready, and if the latter which lens to keep on it. They are situational decisions, influenced largely by what I’m focused on (heh!) at the time—keeping the camera in the bag facilitates collecting, but it also tends to reduce the number of subjects I deem worthy of the setup effort required to photograph them. Conversely, carrying the camera out of the bag greatly impedes collecting but results in much more photographs having been taken. Even when I do decide to carry the camera at the ready, which lens should I have on it—the 100mm for tiger beetle-sized and larger, or the 65mm for tiger beetle-sized and lower? (Annoyingly, most tiger beetles are right at that life-sized threshold, and neither lens alone allows me to float above and below 1:1 for the full range of photos I like for them. As a result, I sometimes end up with extension tubes stacked under the 100mm lens to give me some extra range above its normal 1:1 limit.) I wish there was some way to have the camera with either lens at the ready (and not impeding net swings would be even better), but that just isn’t possible. As a result, I sometimes find myself with the wrong lens on the camera when I see something I want to photograph. If it’s important, I’ll go through the trouble to switch out lenses—hopefully quickly enough to avoid losing the photographic opportunity; other times I might just decide I don’t really need the photo that badly.  Then there are times when I feel a little adventurous and will just go ahead and take the photo anyway without switching lenses.

The following is an example of the latter—an eastern fence lizard (Sceloporus undulatus) photographed with the 65mm lens (minimum magnification 1:1). Not only is this the first time that I have succeeded in approaching one of these lizards closely enough to take a good photograph, but the short working distance of the 65mm required that I get extraordinarily close. He was on the side of a fallen log, and I approached from the other side crouching low, then slowly (slowly!!!) peered over the edge of the log until I had his head in focus. I got off just this one shot, as the flash caused the lizard to bolt for good. The angle could have been better, but I got the eye focused spot-on so it’s a keeper.

Sceloporus undulatus (eastern fence lizard) | Shaw Nature Reserve, Franklin Co., Missouri

I wonder if anybody else has ever photographed a 6-inch long lizard with a 65mm lens…

Copyright © Ted C. MacRae 2011

Mite on White

/ Ted C. MacRae / 32 Comments

I found this velvet mite at Shaw Nature Reserve (Franklin Co.) in east-central Missouri on a trail through mesic upland forest. At 4 mm in length, this member of the superfamily Trombidioidea is a downright honker compared to most other mites. I suspect it belongs to the nominate family, but comments at BugGuide suggest a lateral view of the palps are necessary for a conclusive ID to family. Regardless of its identity, its screaming red color made it ideally suited to be photographed on a white background. On the other hand, its small size and refusal to ever stop crawling made it a frustrating subject to track through a 65mm lens (all photos shown uncropped).


Copyright © Ted C. MacRae 2011

Sawfly larva – Periclista sp.

/ Ted C. MacRae / 13 Comments


As I was photographing spring coralroot orchids in my front yard, I noticed a small green object clinging to the underside of one of the flowers.  Zooming in with the camera lens revealed the object to be a caterpillar, but this was no ordinary caterpillar (i.e., a member of the order Lepidoptera), but rather a sawfly larva.  Sawflies are not lepidopterans, but members of the order Hymenoptera, making them more related to bees and wasps while their larvae look much more like those of a moth or butterfly.  Although there are few absolutes in the world of insects, distinguishing sawfly larvae from lepidopteran caterpillars is as easy as counting the prolegs (false legs behind the three pairs of true legs)—lepidopterans have at most 5 pairs of prolegs (often less), while sawfly larvae always have 6 or more pairs of prolegs.

While its identity as some type of sawfly was immediately apparent, I wasn’t sure beyond that.  One thing I was fairly certain about was that the orchid itself was likely not its host plant.  I could see no evidence of feeding on any part of the plant on which it was resting (and orchids by the large seem relatively free of defoliating insect pests), nor could I find any other sawfly larvae on the plant or its neighbors (where there is one sawfly larva, there are usually more).  Rather, I suspected that it had fallen from one of the many native oaks and hickories that shade the front yard (and which provide the habitat that allows orchids to grow in my front yard to begin with).  Nevertheless, I Googled “orchid sawfly,” only to come up with page after page of links referring to the sawfly orchid (Ophrys tenthredinifera), native to the Mediterranean Region.  That wasn’t much help, so I began the process of slogging through the sawfly images posted at BugGuide in hopes that something close had already been posted.  Eventually I stumbled upon photos of larvae in the family Tenthredinidae, subfamily Blennocampinae that exhibited similar branched dorsal spines (including the pestiferous Monophadnoides rubi, or raspberry sawfly).  I gradually settled on a generic ID of Periclista sp. based on the resemblance of the larva in my photos to those in photos such as this one, and the fact that this genus of ~20 North American species feeds as larvae on oak and hickory seems to support to the identification.

This past week’s Super Crop Challenge was taken from the dorsal side of the caterpillar in the first photo and rotated—it apparently proved a little too tough for most people to handle.  Predictably, most participants guessed one of the different spined caterpillars of the order Lepidoptera, but Dave used the extended quiz time wisely and eventually came up with a correct ID and the challenge win.  He even suggests the species P. marginicollis, based on its widespread eastern distribution and the bifurcate processes—it’s a good guess, but the larval description in Smith (1969) is a little beyond my comprehension, so I’m leaving the ID at Periclista sp.  Dave’s win moves him into the top spot in the current overall standings, while Tim moves up to tie Alex for 2nd place with 9 pts each.

REFERENCE:

Smith, D. R.  1969.  Nearctic sawflies I.  Blennocampinae: Adults and larvae (Hymenoptera: Tenthredinidae).  U.S. Department of Agriculture, Agricultural Research Service, Technical Bulletin No. 1397, 179 pp. + 19 plates.

Copyright © Ted C. MacRae 2011

Super Crop Challenge #5

/ Ted C. MacRae / 19 Comments

Here is the latest Super Crop Challenge – can you identify the structures and the organism (order, family, and genus) to which they belong?  Bonus points will be awarded for relevant supporting information, at my discretion.  Standard challenge rules apply, including moderated comments (to give everyone a chance to participate) and early submitter points for beating others to the same correct answer.  No need to look to exotic locations for the answer, it’s right here in the good ol’ USA.  I’ll follow up in a day or so.

Copyright © Ted C. MacRae 2011

Dromochorus pruinina is not extirpated in Missouri… yet!

/ Ted C. MacRae / 7 Comments

ResearchBlogging.orgWhen Chris Brown and I began our study of Missouri tiger beetles back in 2000, our goal was simply to conduct a faunal survey of the species present in the state.  Such studies are fairly straightforward—examine specimens in the major public and private collections, and do lots and lots of collecting, especially in areas with good potential for significant new records.  Over the next 10 years, however, our study morphed from a straightforward faunal survey to a series of surveys targeting a number of species that seemed in need of special conservation attention.  We were no longer just collecting tiger beetles, but trying to figure out how to save them.

There were good reasons for this—Missouri’s tiger beetle fauna is rather unique due to the state’s ecotonal position in the North American continent.  While its faunal affinities are decidedly eastern, there are also several Great Plains species that range into the state’s western reaches.  Even more interestingly, these western species occur in Missouri primarily as relict populations—widely disjunct from their main geographic ranges further west, and limited in Missouri to small geographical areas where just the right conditions still exist.  These include the impressive (and thankfully secure) Cicindela obsoleta vulturina (prairie tiger beetle), the likely extirpated Habroscelimorpha circumpicta johnsonii (Johnson’s tiger beetle, with Missouri’s disjunct population often referred to as the ‘saline spring tiger beetle’), Cylindera celeripes (swift tiger beetle)—still clinging precariously to existence throughout much of its former range, and the subject of our newest publication, Dromochorus pruinina (frosted dromo tiger beetle) (MacRae and Brown 2011).

We were first made aware of the occurrence of this species in Missouri when Ron Huber (Bloomington, MN) sent us label data from 7 specimens in his collection.  One was labeled from Columbia, Missouri—location of the University of Missouri, and source of many a mislabeled specimen culled from collections of entomology students.  The other specimens, however, collected in 1975 and labeled “10 miles W of Warrensburg” in western Missouri, seemed legit, and in 2003 we began searching in earnest for this species.  Our searches in the vicinity of 10 miles W of Warrensburg were not successful (and, in fact, we had difficulty even locating habitat that looked suitable), but on 15 July 2005 Chris found the species on eroded clay roadsides along County Road DD in Knob Noster State Park—precisely 10 mi east of Warrensburg.  With this collection as a starting point, we began an intense pitfall trapping effort in 2006 to more precisely define the geographical extent of this population in Missouri.  The Knob Noster population was confirmed at several spots along the 2.5-mile stretch of Hwy DD that runs through Knob Noster State Park, but we were surprised to find no evidence of this species at any other location throughout a fairly broad chunk of west-central Missouri (see Fig. 1 above).  We examined the area thoroughly in our search to find suitable habitats for placing pitfall traps, and it became quite obvious that the eroding clay banks that harbored the species in Knob Noster State Park were not extensive in the area.  This observation also seemed to further confirm our suspicion that the label data for the original 1975 collection were slightly erroneous, and that the Knob Noster population was, in fact, represented by that original 1975 collection.

In 2008, we conducted additional pitfall trapping surveys tightly concentrated in and around Knob Noster State Park.  Again, we only found the beetle along the same 2.5-mile stretch of Hwy DD, despite the presence of apparently suitable eroded clay roadsides in other parts of the park.  These other areas were either disjunct from the Hwy DD sites, separated by woodlands that this flightless species likely is not able to traverse, or were fairly recently formed through road construction activities.  These newly formed bare clay roadsides were quite close to the beetle sites, and we are still hard pressed to explain why the beetle has apparently not yet colonized them—perhaps there is some physical or chemical property that the beetle requires that is not present in these more anthropogenically formed habitats.  Whatever the explanation, the result is the same—the entire Missouri population of D. pruinina appears to be restricted to a scant 2.5-mile stretch of roadside habitat in west-central Missouri, disjunct from the nearest population further west (Olathe, Kansas) by a distance of 75 miles.  The highly restricted geographical occurrence of this species in Missouri is cause enough for concern about its long-term prospects, but the relatively low numbers of adults that were encountered—38 throughout the course of the study—is even more troubling.  Dromochorus pruinina is not extirpated in Missouri, but the prospect of such is a little too real for comfort.

As a result of our studies, D. pruinina is now listed as a state species of conservation concern with a ranking of “S1” (critically imperiled)—the highest possible ranking (Missouri Natural Heritage Program 2011).  Despite its highly restricted range in Missouri, the occurrence of this population entirely within the confines of Knob Noster State Park under the stewardship of the Missouri Department of Natural Resources (MDNR) provides some measure of optimism that adequate conservation measures will be devised and implemented to ensure the permanence of this population.  Chief among these is the maintenance of existing roadside habitats, which are kept free of woody vegetation by a combination of mowing and xeric conditions.  True conservation of the beetle, however, can only occur if the area of suitable habitat is significantly expanded beyond its present extent.  Much of the park and surrounding areas are heavily forested and, thus, do not provide suitable habitat for the beetle.  Significant areas within the park have been converted in recent years to open woodlands and grasslands; however, these areas still possess a dense ground layer and lack the patchwork of barren slopes that seem to be preferred by the beetle.  Further conversion of these areas to grasslands with more open structure will be required to create additional habitats attractive to the beetle.  Until this is done, D. pruinina is at risk of meeting the same fate that has apparently befallen the Missouri disjunct population of H. circumpicta johnsonii (Brown and MacRae 2011).

REFERENCES:

Brown, C. R. and T. C. MacRae.  2011.  Assessment of the conservation status of Habroscelimorpha circumpicta johnsonii (Fitch) in Missouri.  CICINDELA 42(4) (2010):77–90.

MacRae, T. C. and C. R. Brown. 2011. Distribution, seasonal occurrence and conservation status of Dromochorus pruinina (Casey) in Missouri CICINDELA 43(1):1–13.

Missouri Natural Heritage Program.  2011.  Species and Communities of Conservation Concern Checklist.  Missouri Department of Conservation, Jefferson City, 52 pp.

Copyright © Ted C. MacRae 2011

Friday Flower – Spring Coralroot Orchid

/ Ted C. MacRae / 15 Comments

As flowers go, I have a passion for orchids.  Despite comprising perhaps the largest family of flowering plants on earth, most people think of orchids as rare, epiphytic plants restricted to the lush, hyper-diverse, tropical rain forests of South America and southeast Asia.  In reality, terrestrial orchids abound in the temperate regions of the Northern Hemisphere, with more than 200 species occurring in the United States and Canada.  Some, such as the lady slippers (genus Cypripedium),  have blossoms as magnificent as their tropical counterparts, while others are less conspicuous and easy to overlook; however, all share the hallmark that unites the family—a modified petal forming a conspicuous lower lip¹

¹ Interestingly, the lip is actually derived from the uppermost petal, but in most species the flower twists during development so that the lip is oriented at the bottom.

Missouri is home to 34 species of orchids (one introduced, and another discovered in Missouri for the first time just a couple years ago).  None of them are truly common like Rudbeckia or Coreopsis, although some are far more common than is realized.  I’ve featured a few of these previously, including Spiranthes magnicamporum (Great Plains Ladies’-tresses), Platanthera lacera (green fringed orchid), Aplectrum hymenale (Adam and Eve orchid), and Goodyera pubescens (rattlesnake plantain orchid).  I’ve traveled to the far corners of the state to see them, but for today’s featured species—Corallorhiza wisteriana (spring coralroot)—I had to travel no further than my front yard.


I’m sure my neighbors hate my front yard. I don’t use fertilizers or herbicides, and I’m unconcerned about the moss that grows amongst the thin stands of mixed grasses under the tall native oaks that shade much of the yard. My neighbor down the street especially probably shakes his head as he walks his dog past my yard every day, frustrated that I don’t share his passion for the lush, thick, über-green bluegrass monoculture that he has achieved (and must pay somebody to cut at least once a week). Spring must be especially frustrating for him, as I don’t even cut the grass until late May, giving the lawn an especially ragged, unkempt appearance. However, whatever my yard lacks in graminaceous greatness, it more than makes up for in its diversity of woodland natives—spring beauty, toothwort, trout lily, violets, coral bells… and spring coralroot. I have several colonies growing at different spots in the yard, all marked with surveyor’s flags to prevent accidental trampling until their bloom period ends and I can (begrudgingly) begin mowing the grass (no more than once a month, if I can get away with it). I’ve enjoyed these coralroot colonies every spring since I’ve lived here, but this spring was the first that I took the opportunity to photograph their blooms.

Of the three Corallorhiza species that can be found in Missouri, C. wisteriana is the most common, occurring in rich or rocky acidic soils of low wooded valleys, ravine bottoms, along streams and on ridges and slopes of open woods (Summers 1981).  My yard qualifies as the latter, occurring on a limestone ridge in mesic upland forest made only slightly more open by the late 1980s construction of the neighborhood and its minimal disturbance limited to the roads, driveways, home footprints and a small amount of associated lawn.  It is distinguished in Missouri from C. odontorhiza (Autumn coralroot) by its spring flowering period and larger flowers with notched or lobed lip, and from the rare C. trifida (known from only a few Missouri counties) by the purple or brownish stems and spotted lip.


As suggested by the unusual coloration, Corallorhiza species are largely (though not completely) lacking in chlorophyll, and as a result are mostly unable to photosynthesize their own food. Instead, the bulbous rhizomes remain hidden within the soil for much of the year, forming symbiotic relationships with soil fungi and flowering only when conditions are favorable (Luer 1975). The past several springs have been wet here, and accordingly I’ve been rewarded with the wonderful sight of these exquisite tiny blossoms.

I can’t say that I’m entirely happy with these photographs, as I found it difficult to get the entire blossom in focus—when the petals were in focus the lip was not, and vice versa, even in straight lateral profile.  Nevertheless, they still show the delicate structure of the lip, with its scalloped edge and crystalline-appearing surface.  The blooms are fading now—soon there will be no above-ground evidence of their existence, and my neighbor and wife will likely gang up on me to finally power up the lawn mower.

REFERENCES:

Luer, C. A.  1975.The Native Orchids of the United States and Canada Excluding Florida.  The New York Botanical Garden, 361 pp. + 96 color plates.

Summers, B.  1981. Missouri Orchids.  Missouri Department of Conservation, Natural History Series No. 1, 92 pp.

Copyright © Ted C. MacRae 2011

Bichos Argentinos #13 – Spotted Maize Beetle

/ Ted C. MacRae / 9 Comments

Astylus atromaculatus (spotted maize beetle) | Inés Indart, Argentina.

One of the most common insects encountered in agricultural fields in Argentina is Asylus atromaculatus (spotted maize beetle).  This native species can also be found further north in Bolivia and Brazil, and as implied by its common name it is frequently encountered in maize fields.  The species, however, is also common on soybean, on which the individual in the above photo (and mating pair in the previous post) were found.  Looking like some strange cross between a checkered beetle (family Cleridae) and a blister beetle (family Meloidae), it is actually a member of the Melyridae (soft-wing flower beetles)—placed with the Cleridae in the superfamily Clerioidea.

Despite its abundance (and the resultant attention it gets from growers), the pollen feeding adults are of little economic importance.  It’s easy to see, however, why this species gets so much attention from growers—during January through March the adults occur in tremendous numbers, congregating on a wide variety of flowering plants, but especially corn. Their large numbers are an impressive sight, with literally dozens to even hundreds of adults occurring on a single plant. Tassles—the source of corn pollen—are highly preferred, but when populations are heavy the silks and any exposed ears are also popular congregation sites. Despite their numbers, the impact of the beetles on yield is rarely sufficient to warrant the cost of control measures.


Whatever economic impact the species might have is actually due more the larvae—hidden within soil—than to the super-abundant and highly conspicuous adults. Feeding primarily on decaying plant matter within the soil, larvae do occasionally attack newly planted corn, either before or just after germination. Their attacks are more common in dry years and in severe cases can lead to the need to replant a field. This seems to be more common in South Africa, where the species was introduced in the early 1900s, than in its native distribution in South America.


Whenever I see a ubiquitous, diurnal, brightly and contrastingly colored insect, the first suspicion that comes to my mind is aposematic (warning) coloration and chemical defense against predation. There seems to have been some investigation into the toxicity of this species (Kellerman et al. 1972), and in South Africa they have been implicated in poisoning of livestock when accidentally ingested with forage (Bellamy 1985).  Few other reports of toxicity by beetles in this family are known, but four species of the genus Choresine have been shown to produce high levels of batrachotoxin alkaloids—these are the same toxins found in the skin of poison-dart frogs of the genus Phyllobates (Dumbacher 2004).  The frogs are unable to synthesize these toxins themselves, thus, it is presumed that they sequester these compounds from their diet—whether it is from some species of Melyridae remains to be determined.

Congratulations to Alex Wild and Max Barclay, who both answered the call to ID Challenge #8 and correctly determined all taxa from order to species.  Alex, by way of submitting his ID first, gets a bonus point and leads the current BitB Challenge session with 9 points.  Thanks to the rest who played along as well—see my response to your comments for your points earnings.

REFERENCES:

Bellamy, C. L. 1985.  Cleroidea, pp. 237–241.  In: Scholtz, C. H. and E. Holm (Eds.), Insects of Southern Africa, Butterworths, Durban.

Dumbacher, W. A., S. R. Derrickson, A. Samuelson, T. F. Spande and J. W. Daly. 2004.  Melyrid beetles (Choresine): a putative source for the batrachotoxin alkaloids found in poison-dart frogs and toxic passerine birds.  Proceedings of the National Academy of Sciences, USA 101(45):15857–15860.

Kellerman, T. S., T. F. Adelaar and J. A. Minne. 1972. The toxicity of the pollen beetle Astylus atromaculatus Blanch. Journal of the South African Veterinary Medical Association 43(4):377–381.

Copyright © Ted C. MacRae 2011