Missouri

What’s black and white and red all over?

/ Ted C. MacRae / 19 Comments

Last September, labmate and fellow insect collecting enthusiast Stephen Penn and I visited the dolomite glades of the White River Hills in extreme southwestern Missouri. Our main quarry was tiger beetles, specifically a disjunct population of the large and impressive Prairie Tiger Beetle (Cicindelidia obsoleta vulturina) that lives only on the glades in this area and adjacent Arkansas. I was hoping to find additional localities for the beetles in the more western parts of the region where it’s precise distribution in Missouri is less well known. First, however, I wanted to make sure the beetle was out, so we started at the westernmost of its known locations—Chute Ridge Glade at Roaring River State Park. As we picked our way through dry-mesic woodland bordering the more open glades, a large, dead chinquapin oak (Quercus muehlenbergii) with sloughing bark caught my eye. One never knows what might be encountered under bark, regardless of the season, and as I pulled away the very first slab of bark I was rewarded with the sight of what must be North America’s most beautiful assassin bug, Microtomus purcis.

Microtomus purcis

Microtomus purcis (Drury, 1782) | Barry Co., Missouri

Sometimes called the “bark assassin bug”, this species is not quite as large as the better known “wheel bug” (Arilus cristatus) but makes up this by its spectacular coloration—black with the base of the wings prominently marked creamy-white and parts of the abdomen and hind legs bright red. One would think such a conspicuously  marked assassin bug with a bite powerfully painful enough to back up its apparent warning coloration could brazenly venture out during the day with little to fear. To the contrary, this species seems best known for its habit of hiding under bark during the day and venturing out only at night, during which time it is sometimes attracted to lights (Slater & Baranowski 1978, Eaton & Kaufman 2007). A majority of BugGuide photos of the species also mention finding them under bark or apparently attracted to lights.¹

¹ I was especially amused by this particular photo for which the contributor states, “While holding it, the bug pierced my finger nail with its proboscis. The pain was searing and I have a small blood stain under the nail.” I’ll admit it—I, too, learned firsthand how painful the bite of an assassin bug can be when I picked one up, in my case Melanolestes picipes, with plans to include it in my Entomology 101 collection.

Sunset on the glade

Sunset on the glade | Pilot Knob Conservation Area, Stone Co., Missouri

I, in fact, have only seen this species once before—also in Missouri and again under bark, although that time was during the winter, thus causing me to think this was its overwintering habit. I placed the individual in a glass vial and brought it indoors to “revive” it, but to my disappointment when I checked on it a few days later it was dead. Froeschner (1944) reported this species (under its older name, Hammacerus purcis) was “not uncommon” in Missouri, though apparently confined to the Ozark Highlands south of the Missouri River. Adult records in Missouri extended from September to March, with small nymphs being found during November and December, but BugGuide records include summer months as well. If I want to see this species more than twice in 30 years, I supposed I am going to have to spend more time peeling bark, or checking lights.

REFERENCES:

Eaton, E. R. & K. Kaufman. 2007. Kaufman Field Guide to Insects of North America. Houghton Mifflin Harcourt, New York, 391 pp. [Amazon preview].

Froeschner, R. C. 1944. Contribution to a synopsis of the Hemiptera of Missouri, Pt. III. Lygaeidae, Pyrrhocoridae, Piesmidae, Tingidae, Enicocephalidae, Phymatidae, Ploiariidae, Reduviidae, Nabidae. The American Midland Naturalist 31(3):638–683 [JSTOR preview].

Slater, J. A. & R. M. Baranowski. 1978. How to Know the True Bugs. The Pictured Key Nature Series, William C. Brown Company Publishers, Dubuque, Iowa, x + 256 pp. [Amazon description].

© Ted C. MacRae 2015

Missouri Master Naturalists Seminar

/ Ted C. MacRae / 4 Comments
Missouri Master Naturalist Confluence Chapter Seminar | December 9, 2014. Photo by Lee Phillion.

Speaking to the Missouri Master Naturalist Confluence Chapter, December 9, 2014. Photo by Lee Phillion.

Earlier this week I had the privilege of speaking to the Confluence Chapter of the Missouri Master Naturalist Program, the members of which are all graduates of the Missouri Master Naturalist Program. This community-based natural resource education and volunteer service program, sponsored by the Missouri Department of Conservation and the University of Missouri Extension Service, seeks to engage Missourians in the stewardship of our state’s natural resources through science-based education and volunteer community service. To accomplish such, members support conservation efforts and natural resource education in their local communities.

Since I’ve studied the insect fauna of Missouri for many years now, especially in its threatened and endangered natural communities, I thought a talk on this subject might be of interest to the group. I decided to focus on some of the work I’ve done in two of our state’s most critically imperiled natural communities: loess hilltop prairies in the northwest corner of the state and sand prairies in the southeastern lowlands—with a talk titled, “From Hilltops to Swamps: Insects in Missouri’s Rarest Prairies”. The presentation provided an overview of each of these natural communities, the circumstances that have led to their rarity in Missouri, and the insects associated with them with special emphasis on species that are dependent upon these natural communities for survival. For those who might be interested, I’ve posted a PDF version of the presentation here.

From Hilltops to Swamps: Insects in Missouri’s Rarest Prairies

Truth be told, it was one of the most enjoyable seminars I’ve ever given, due mostly to a wonderfully engaged audience of about 70 people. It was a perfect opportunity for me to promote awareness of insects and the need to consider them in conservation efforts with an audience whose members are at the forefront of the citizen science effort within our state. I extend my heartiest thanks to Leslie Limberg for giving me the opportunity to speak, Lee Phillion for sending me photos from the event, including the one posted above, and—most importantly—the members of the audience for the warm welcome they extended to me and the interest they showed during my presentation.

© Ted C. MacRae 2014

Missouri’s largest planthopper

/ Ted C. MacRae / 4 Comments

Although I have long dedicated myself to beetles, I must confess that my first love was the so-called “Homoptera”—that now defunct order containing some really cool bugs (cicadas and hoppers—i.e., leafhoppers, treehoppers, planthoppers, froghoppers, armadillohoppers, etc.) and some not-so-cool bugs (aphids, whiteflies, mealybugs, and their kin)¹. Perhaps you already sense that it was only the cicadas and hoppers that I really liked, the other mentioned groups being… well… boring from my perspective as a collector (overwhelming numbers of tiny, soft-bodied, sessile insects that required preservation in alcohol or on slides²). Even within the “cool” homopterans, however, some groups interested me more than others. Leafhoppers were okay, but my interest in them derived mostly from the fact that they were the subject of my thesis work. Treehoppers, on the other hand, were my favorite because they were just so adorably bizarre, and cicadas also fascinated me due to their size and behavioral charisma.

¹The homopterans have since been subsumed within the larger order Hemiptera (true bugs)—an irritating but necessary consequence of molecular studies that have shown rather conclusively that hoppers and cicadas are more closely related to the other true bugs than they are to the group containing aphids, whiteflies and mealybugs.

²So, not only are they boring to curate, but they directly caused the first order of insects in which I became interested to be completely dismantled!

Poblicia fuliginosa on Silphium terebinthinaceum (prairie dock)| Barry Co., Missouri.

Poblicia fuliginosa on Silphium terebinthinaceum | Barry Co., Missouri.

The planthoppers also interested me, although many of the various families contained within the group seemed not much different to me than leafhoppers. One family, however, stood out—the Fulgoridae. Much larger than the other planthoppers, they seemed like a cross between a planthopper and a small cicada (okay, a very small cicada)—combining the hopping capabilities of the former with the size (almost) of the latter. I only rarely encountered these bugs in Missouri; actually it was only a single species that I ever found—Poblicia fuliginosa, one of only two species in the family known to occur as far north as Missouri (Bartlett 2014). Moreover, when I did find them, they were extraordinarily wary and difficult to approach and collect. Vernon Brou, in a comment at this species’ BugGuide page, describes their capture-avoidance capabilities perfectly:

These are nearly impossible to capture by hand netting, they are rocket propelled. A most [frustrating] exercise in futility.—Vernon Antoine Brou, Jr., pers. comm. to Mike Quinn, 2012.

The abdomen is brightly colored red (barely visible in this photo).

The abdomen is brightly colored red (barely visible in this photo).

This past fall, while on a collecting trip in the White River Hills of extreme southwestern Missouri, I chanced upon a few individuals perching on the stems of prairie dock (Silphium terebinthinaceum) in a dolomite glade. Remembering how wary they were in my previous encounters, I figured I had little chance of successfully photographing any of them. I love a challenge, however, and with the help of field mate Stephen Penn I managed to get the shots shown here. Getting within the range of focus generally caused the insects to dart around to the backside of the stem. I took advantage of this behavior by getting myself set and focusing the camera on the bug (even though it was behind the stem) and then having Stephen move his insect net slowly toward the bug from the side to get it to dart back around the stem away from the net… right into my field of view! The first individual we tried to photograph took off rather quickly (rocket-propelled!), but fortunately we found another individual in the same clump of stems and succeeded in getting some shots.

In the second photo the bright red abdomen is barely visible on the underside of the insect. The entire abdomen is, in fact, bright red in obvious contrast to the otherwise dark and somber coloration of the insect. I’ve searched the literature but can find no mention of the function of the red abdomen, but I presume it serves a flash coloration function similar to the bright green abdomen of some jewel beetles to confuse potential predators by its visibility in flight and then sudden disappearance when the insect lands and folds its wings over the abdomen. I suppose an aposematic function is also possible given the red coloration, but I’m not aware that any hoppers are known to be chemically protected, and the fact that the red abdomen is seen only during flight also suggests a non-chemically based function.

REFERENCES:

Bartlett, C. R. 2014 (and updates). Planthoppers of North America. Available at: http://canr.udel.edu/planthoppers (accessed 12 November 2014).

© Ted C. MacRae 2014

North America’s Most Beautiful Agrilus Jewel Beetle

/ Ted C. MacRae / 6 Comments

For the past few years I’ve spent the summers traveling once a month or so from my home near St. Louis to research plots in western Tennessee. I enjoy these trips immensely—not only are my research and the colleagues that I spend time with fun, but I also get to keep an eye on the progression of the season in one of Missouri’s most interesting (and threatened) natural communities: the southeastern lowlands. Spring sees the emergence of an unusual population of the Festive Tiger Beetle (Cicindela scutellaris) in the area’s critically imperiled sand prairies; summer harks the appearance of the diminutive and almost-impossible-to-see Ant-like Tiger Beetle (Cylindera cursitans) in the ribbons of wet bottomland forest that line the Mississippi River; autumn is graced by the sight of stunningly beautiful amorpha borers (Megacyllene decora) in wet areas hosting mixed stands of false indigo (Amorpha fruticosa) and goldenrod (Solidago spp.); and all season long a variety of seldom-seen insects (e.g., longhorned beetles that look like stag beetles) are attracted to ultraviolet lights set up in the area’s increasingly scarce natural habitats.

Hairy mallow (Hibiscus lasiocarpus), host for Agrilus concinnus

Hairy mallow (Hibiscus lasiocarpus), host for Agrilus concinnus

Another phenological event that I look forward to in the southeastern lowlands is the blooming period of hairy mallow (Hibiscus lasiocarpus). Starting in July and reaching its peak in early to mid-August, the enormous white (and sometimes pink) flowers explode across the landscape at a time when precious few other flowers can be found, conspicuously flagging any ground where water tends to stand. It is not the flowers themselves, however, that pique my interest, but rather a beautiful (and, until recently, rare) jewel beetle (family Buprestidae)—Agrilus concinnus—that becomes active on the plants while they are in flower. In fact, of the nearly 200 species belonging to the genus in North America, I consider A. concinnus to be perhaps the most beautiful!

Agrilus concinnus | Stoddard Co., Missouri

Agrilus concinnus | Stoddard Co., Missouri

I first saw this species in Missouri’s southeastern lowlands nearly 30 years ago. At that time, I didn’t know that the mating pair that I had found on low vegetation represented a species considered to be one of the rarest of the genus in North America (having been recorded only from Florida, Georgia, Illinois, and Texas and not yet known from Missouri) and whose host plant and biology were completely unknown. Over the course of several years following this first find, fellow buprestophile Gayle Nelson (now deceased) and I were able to document the occurrence of this species also in Kansas (MacRae & Nelson 2003) and confirm its association with plants in the genus Hibiscus (MacRae 2006). We also determined that adults of this species exhibited an unusually late seasonal occurrence, peaking in late July and early August, compared to the spring adult activity period of most other eastern North American species in the genus. As a result of these efforts, one of North America’s rarest and least known jewel beetles was no longer regarded as either. A more detailed summary of my experiences with this beetle can be found in a newsletter article that I wrote a while back (MacRae 2004).

Hibiscus lasiocarpus

Plants in peak bloom signals the adult activity period of the beetle.

Of course, those were the days before I began photographing insects, so despite the abundance with which I have seen this species in past years, I still lacked photographs of it. I first made an effort to photograph adults two years ago while on one of my research plot trips, but 2012 was characterized by a severe drought in the central U.S.—precious few potential host plants were found at the locality where I first collected these beetles, and those that were present were severely stunted and in poor shape due to the drought. Conditions were much more favorable last year (2013), but again no beetles were seen during an early August visit. This past season was again favorable for growth of the host plants, and though my visit during early August again looked like it was not going to pay off, I eventually scared up an adult and watched it as it flew to another plant. I would see four adults on the day—not a lot, but enough to make sure that I got photographs showing how spectacularly beautiful they are!

Agrilus concinnus

Adults perch, mate, and feed on the upper leaf surfaces.

REFERENCES:

MacRae, T. C. 2004. Beetle bits: Hunting the elusive “hibiscus jewel beetle”. Nature Notes, Journal of the Webster Groves Nature Study Society 76(5):4–5 [pdf].

MacRae, T. C. 2006. Distributional and biological notes on North American Buprestidae (Coleoptera), with comments on variation in Anthaxia (Haplanthaxia)viridicornis (Say) and A. (H.) viridfrons Gory. The Pan-Pacific Entomologist 82(2):166–199 [pdf].

MacRae, T. C. & G. H. Nelson. 2003. Distributional and biological notes on Buprestidae (Coleoptera) in North and Central America and the West Indies, with validation of one species. The Coleopterists Bulletin 57(1):57–70 [pdf].

© Ted C. MacRae 2014

Orange and black on gold

/ Ted C. MacRae / 2 Comments
Trigonopeltastes delta on goldenrod (Solidago sp.) flowers | Stoddard Co., Missouri

Trigonopeltastes delta on goldenrod (Solidago sp.) flowers | Stoddard Co., Missouri

The spectacular amorpha borer, Megacyllene decora, was not the only black-and-gold colored beetle that I saw on the flowers of goldenrod (Solidago sp.) a few weeks ago. In addition were several delta flower scarabs, Trigonopeltastes delta. This species is much more commonly encountered than the amorpha borer—not only geographically but also throughout the season on a greater diversity of flowers. Nevertheless, I had failed in my previous attempt to photograph the species at the very same locality just a few weeks earlier due to the much higher summer temperatures and resultant flightiness of the beetles.

Trigonopeltastes delta
In the case of this beetle, the scientific name almost completely describes the beetle—the genus name being derived from the Greek words trigon (i.e., triangle, triangular) and pelt, (i.e., a shield), referring to the triangular and shield-shaped pronotum, and the species name based on the Greek letter Δ (“Delta”) in reference to the distinctive white triangle on the pronotum that resembles it. I mentioned the diversity of flowers on which adults of this beetle can be found. Pascarella et al, (2001) found this species on 13 different plant species (including mass aggregations numbering in the thousands on inflorescences of Sabal palm, Sabal palmetto) in their study of flower-visiting insects in the Everglades National Park. In Missouri, I see these beetles most commonly on Queen Anne’s lace (Daucus carota) and several other plants with white inflorescences such as American feverfew (Parthenium integrifolium), New Jersey tea (Ceanothus americanus), wild hydrangea (Hydrangea arborescens), and—most recently—hairy mallow (Hibiscus lasiocarpos). Interestingly, on this day there was an abundance of white-flowered snakeroot (Eupatorium sp.) in bloom at the same site, but I only saw the beetles on the yellow-flowered goldenrod.

Trigonopeltastes delta
It has been suggested that the Delta pattern on the pronotum and orange-and-black coloration of the elytra combine to mimic the appearance of paper wasps in the genus Polistes. Paper wasps are frequent visitors to many of the same flowers that these beetles frequent; however, the much smaller size of the beetles might suggest mimicry of aculeate hymenopterans (stinging wasps and bees) in general rather than paper wasps specifically. A more unusual type of mimicry has also been suggested in that a rear view of the beetle with its large, white, triangular pygidium seems to resemble the head of a hornet. Supporting this idea is the habit of the beetles to raise and hold their long hind legs in the air when disturbed in a manner that makes them resemble a hornet’s antennae!

Defensive posture with hind legs raised above abdomen.

Defensive posture with hind legs raised above abdomen (iPhone photo).

REFERENCE:

Pascarella, J. B., Waddington, K. D. & P. R. Neal. 2001. Non-apoid flower-visiting fauna of Everglades National Park, Florida. Biodiversity and Conservation 10(4):551–566 [abstract & pdf link].

© Ted C. MacRae 2014

Amorpha borer on goldenrod

/ Ted C. MacRae / 5 Comments
Megacyllene decora (amorpha borer) | Stoddard Co., Missouri

Megacyllene decora (amorpha borer) | Stoddard Co., Missouri

One of my favorite longhorned beetle species is the amorpha borer, Megacyllene decora. Like its close relative, the locust borer—M. robiniae, this large, beautiful, black and yellow beetle is a classic harbinger of fall by virtue of its late-season adult activity period and affinity to flowers of goldenrod (Solidago) and snakeroot (Eupatorium). Compared to the locust borer, however, it is larger, chunkier, and more boldly marked, and despite the commonness of goldenrod flowers it is far less commonly encountered than the locust borer due to the more restricted habitat preferences of the larval host plant (false indigo—Amorpha fruticosa).

Megacyllene decora
The beetle in these photos is one of two that I found in late September at a site in the lowlands of southeastern Missouri. I’ve not seen the beetle at this site before, but I knew it must occur here because of the stands of false indigo that I noted during an earlier visit to the site. Considering the large number of plants present, two beetles is much less than I would have expected to see (in fact, both beetles were found in a single patch of goldenrod). I have previously featured this species (see A classic fall ‘bycid) from a site about 50 miles east of this one. At that site also only a few beetles were seen despite an abundance of larval host plants (but the adults occurring on snakeroot flowers instead of goldenrod). Only twice have I seen this species in numbers that I would consider plentiful (both times in western Missouri).

Megacyllene decora
Amorpha borers and locust borers are part of a larger complex of black and yellow insects that visit goldenrod flowers in the fall. These include a variety of bees, wasps, and other beetles (e.g., the delta flower scarab, Trigonopeltastes delta—family Scarabaeidae), but perhaps the most abundant is the goldenrod soldier beetle, Chauliognathus pensylvanicus—family Cantharidae (also called the Pennsylvania leatherwing). One can presume that any or all of these species serve as models for the longhorned beetles—bees and wasps are obviously protected from most predators by their ability to sting, and the bodies of soldier beetles are chemically protected by cantharidin, a highly toxic terpenoid that causes blistering and irritation of mucous membranes at low doses and can be fatal at higher doses. As the mimics, amorpha borers and locust borers could be expected to be less abundant than the models. However, considering how difficult-to-see these beetles can be when sitting on goldenrod flowers, their black-and-yellow coloration seems as though it could just as easily serve a cryptic function. It is even possible that mimicry and crypsis both have contributed to evolution of these beetle’s coloration.

Ted C. MacRae 2014

A truly disturbed garden spider

/ Ted C. MacRae / 15 Comments
Argiope trifasciata vibrating web in response to disturbance.

Argiope trifasciata shaking its web in response to being approached.

This past weekend I made a trip to the White River Hills region in extreme southwestern Missouri. My goal was to find additional localities of the prairie tiger beetle (Cicindelidia obsoleta vulturina), which inhabits dolomite glades in the area and is disjunct from the main distribution in Texas and Oklahoma. As I was checking a particularly large glade complex in Roaring River State Park, I came upon this banded garden spider (Argiope trifasciata) that had spun its web across the span of branches from a gum bumelia tree (Sideroxylon lanuginosum). As I approached the spider the web began moving back and forth quite vigorously, and it occurred to me that there was not nearly enough wind for the web to be shaking to such degree. I stood still, and eventually the shaking stopped and the web became still again. To test whether it was really the spider shaking the web intentionally, I raised my net to one side and drew it closer to the spider, and once again the web began shaking back and forth just as vigorously as before. I watched the spider closely as the web shook, and I could see that the spider was actually flexing its two front pairs of legs back and forth to cause the shaking. It was clear at this point that the spider was doing this in response to my approach, probably as a defensive reaction to a perceived threat.

I suppose I have seen this behavior before but always assumed the web was just shaking in the breeze. Not until this time, with no wind to speak of and the web shaking quite rapidly, did it become clear to me that this was actually an intentional behavior exhibited by the spider. Eisner (2005) also notes this behavior, stating that Argiope spiders often engage…

…in a bobbing action, whereby through a quick flexion of its legs it sets the web into vibration, making itself a blurred target that is hard to grasp.

The photos used to make this animated gif were not easy to get. The spider was situated in a rather high and awkward-to-reach spot, and the iPhone had difficulty focusing on the spider while it was in motion. I overcame these problems by setting myself in a stable position, holding the iPhone in place, zooming the screen slightly (about 33%) and locking focus on the spider while it was still, and then asking my field buddy (Steve Penn) to approach the spider to trigger shaking. Once it began shaking it was a matter of holding down the shutter while keeping myself and the camera still long enough for a sufficient burst of photos (eight photos were used in this gif).

REFERENCE:

Eisner, T. 2005. For the Love of Insects. Harvard University Press, Cambridge, Massachusetts, 448 pp. [Google Books].

© Ted C. MacRae 2014

Not quite adult

/ Ted C. MacRae / 3 Comments

For the past few years I’ve had research plots in northwestern Tennessee. Each summer, once a month or so, I make the 5-hour drive to the site and spend the afternoon taking data. Any normal person would then check in to their hotel room in town, watch television, and make the drive back to St. Louis the next morning. Of course—I’m not normal, I’m an entomologist! The southeastern lowlands of Missouri, where over the years I’ve found (and continue to find) a number of good spots for collecting insects, are tantalizing close. Instead of retiring immediately to my hotel room, I’d rather head back to the lowlands and find a good spot for setting up a blacklight. It might be midnight before I finally get to a hotel room, but it’s all worth it. Some of the most interesting insects that I’ve featured here during the past few years have come to blacklights on one of these trips, including the primitive longhorned beetles Parandra glabra and Mallodon dasystomus and adult male bagworms, Thyridopteryx ephemeraeformis.

Subadult female, poss. Maccaffertium sp. | Mississippi Co., Missouri

Subadult female mayfly (prob. Maccaffertium sp.) | Mississippi Co., Missouri

Most of the spots I’ve found are located along the Mississippi River, a downside of which is the overwhelming abundance of aquatic insects that are often attracted to the lights. Caddisflies (order Trichoptera) are the worst, sometimes swarming the lights with such frenetic abundance that to check the sheets one must button the collar, hold the breath, dash in quickly to look at the sheet, and retreat just as quickly lest the fluttering hordes find their way up the nostrils, down the ear canals, and into the eyes. Mayflies (order Ephemeroptera) also can be attracted in great numbers, although they tend to be, fortunately, much calmer and better behaved on the sheet than their trichopteran counterparts. Normally, I pay little attention to these insects other than what is required to avoid breathing them—their abundance almost makes them unnoticeable. On one particular night in early August, however, my eyes caught the soft glow of a ghostly-white insect sitting on the underside of a leaf some yards away from the light. I looked closer to see it was a mayfly, and so pale was its coloration that I knew it would make for a striking photograph against the black night sky.

The reason for its milky-white coloration is due to a unique aspect of mayfly developmental biology—they are the only insects to develop fully functional wings before their final molt to adulthood. This stage, called the sub-adult or subimago, emerges from the water where it spent the past year as a nymph (also called a naiad) and flies to nearby vegetation, but it is still not mature. One additional molt is required, wings and all, before the insect finally reaches adulthood and can spend the few remaining hours of its life in single-minded pursuit of a mate. Sub-adult mayflies are distinguished from their adult counterparts by their paler coloration and opaque rather than clear wings. We can also tell that this individual is a female because no claspers are visible at the tip of the abdomen (which males possess for mating) and its relatively small eyes (the eyes of males almost completely cover their head).

My thanks to Dr. Robert Sites, who initially suggested this might be a species in the family Heptageniidae, and to Roger Rohrbeck for confirming my subsequent identification as probably belonging to the genus Maccaffertium.

© Ted C. MacRae 2014