Arthropoda

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

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

Stink Bugs on Soybean in Argentina

/ Ted C. MacRae / 17 Comments

Despite the natural history and taxonomic focus on beetles and other insects I have adopted for this blog, I am by day an agricultural research entomologist.  For the past 15 years soybean entomology has been my focus, and there is no better nexus for soybeans and entomology than South America.  Cultivated hectares have increased dramatically in Argentina and Brazil over the past several decades, now totaling nearly 80 million acres in those two countries alone (roughly the same area as in the US, by far the world’s largest producer of soybean).  Unlike the US, however, where insect pressure is minor outside of a small number of acres in the southeast, significant pressure occurs in nearly 100% of South America’s soybean acres.  Lepidopterans, primarily species in the family Noctuidae such as velvetbean caterpillar (Anticarsia gemmatalis) and soybean looper (Pseudoplusia includens), are the most important pests, followed closely by stink bugs.  This latter group is especially problematic for growers to deal with.  Stink bugs feed on the developing seeds, causing direct yield impacts through reductions in weight and quality, and because they are a guild of insects rather than a single species, differences in product efficacy against the different species can lead to ineffective or inconsistent control.  I’m involved in trying to do something about this, and while I hate to be deliberately coy, suffice it to say that there is an awful lot of insecticide being sprayed on an awful lot of acres and that the world really would be better off if this weren’t the case.

During my recent visit to Argentina this past March, I took advantage of the opportunity while touring soybeanland to photograph a number of these stink bug species.  Proper identification of stink bugs in a crop is the first step towards controlling them, thus I present here my own photographic guide to some of the more important stink bug species found on soybean in Argentina.

Nezara viridula (chinche verde), adult | Pergamino, Argentina

Nezara viridula, 5th instar nymph | San Pedro, Argentina

Nezara viridula, 1st instar nymphs on egg mass | Oliveros, Argentina

Piezodorus guildinii (chinche de las leguminosas), adult | Pergamino, Argentina

Piezodorus guildinii, 1st instar nymphs on egg mass | Acevedo, Argentina

Edessa meditabunda (alquiche chico), adult | Acevedo, Argentina

Edessa meditabunda, 1st instar nymphs on egg mass | San Pedro, Argentina

Edessa meditabunda, eggs nearing eclosion (note eye spots) | Oliveros, Argentina

Euschistus heros (chinche marrón), adult | Oliveros, Argentina

Dichelops furcatus (chinche de los cuernos - note two ''horns'' in front), adult | Inés Indart, Argentina

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

Bichos Argentinos #12 – Lace Bugs

/ Ted C. MacRae / 9 Comments

Corythaica cyathicollis on upper leaf surface of Solanum granuloso-leprosum.

Shortly after entering La Reserva Ecológica Costanera Sur (Buenos Aires, Argentina) during my early March visit, I noticed a fairly large patch of solanaceous-looking shrubs.  Even from a distance, I could see patterns of white stippling on the foliage immediately identifiable as signs of lace bugs, true bugs (order Hemiptera) in the family Tingidae.  As the only arborescent solanaceous plant recorded from the reserve, I was quickly able to identify the plant as Solanum granuloso-leprosum (Haene and Aparicio 2007), but I expected an identification of the bug to be much more difficult to come by.  Afterall, 84 species of tingids distributed in 25 genera have been recorded from Argentina (Montemayor and Cascarón 2005), and lace bug photos aren’t very frequently encountered in the variety of web sites that I visit when trying to get a lead on the identity of insects outside my area of expertise.

Corythaica cyathicollis adult. The black spots either represent frass or protective egg coverings.

Still, I had a clue—the association of the species with Solanum. Lace bugs are predominantly specialist feeders, with many species showing fidelity to a particular plant genus or group of related genera. The genus Solanum contains a number of economically important species, thus, it was a good bet that this species has at some point been considered an economic pest. With this in mind, I opened my volume of Heteroptera of Economic Importance (Schaefer and Panizzi 2000) to the chapter on lace bugs (Neal and Schaefer 2000) and began looking through the species accounts for South American species recorded on Solanum or other species in the family Solanaceae. I only had to reach the second species account before finding Corythaica cyathicollis and the statement “This Neotropical species is a pest on many solanaceous crops…” The identification was confirmed when I found a rather complete description of the species’ systematics, biology, and economic importance (Kogan 1960), complete with line drawings of the adults and all immature stages. Comparison of my photos with these drawings leaves little doubt that this is, indeed, C. cyathicollis.  (Interestingly, Montemayor and Cascarón (2005) list 28 species of Solanum as recorded hosts for C. cyathicollis in their Argentina checklist; however, S. granuloso-leprosum is not among them…)

Corythaica cyathicollis late-instar nymphs.

The bristles of needle-like setae exhibited by the nymphs may be useful for species identification by entomologists (and even phylogenetic analyses—see Guilbert 2005), but for the nymphs themselves it seems fairly obvious that they serve some adaptive function for protection. Neal and Schaefer (2000) note that nymphs of many species of Tingidae seem to be protected by a wide variety of other adaptive mechanisms as well, including maternal care, the production of alarm pheromones and possibly the secretion of noxious compounds. Indeed, most tingids occur in multiple aggregations with large numbers of nymphs of the same species on a single host plant relatively free of predation and parasitism—it is difficult to imagine that such aggregations could exist without employing a strong arsenal of multiple defense mechanisms.

A presumably teneral adult Corythaica cyathicollis.

Occasional adults were seen within the aggregations that showed decidedly lighter coloration than the majority of adults seen. The aggregations were comprised primarily of adults and late-instar nymphs, so I presume these light-colored adults represented newly molted, teneral individuals that will eventually assume normal coloration once their new adult exoskeleton fully hardens.

Adult Gargaphia lunulata on lower leaf surface of Ricinus communis.

Later in the day, I encountered a different lace bug species on a different shrub—Ricinus communis.  This is the famous castor oil plant, a member of the Euphorbiaceae, native to the Old World and now widely distributed throughout tropical regions.  Despite castor oil’s reputed ability to heal wounds and cure ailments, the beans and other plant parts also contain ricin—a toxin with known insecticidal properties.  Apparently these lace bugs possess some mechanism that makes them immune from its effects.

Gargaphia lunulata 5th instar nymphs (and an apparent 1st instar in lower left corner).

This species was also fairly easy to identify—one of the species listed in Neal and Schaefer (2000) as feeding on Ricinus is Gargaphia lunulata, which they note feeds on several useful South American plants belonging to a number of families, including the Euphorbiaceae.  Photographs and drawings of this species can be found in Ajmat et al. (2003) and agree well with the adults and nymphs I found on this plant.  Unlike C. cyathicollis, which were found on the adaxial (upper) surface of the leaves, I found G. lunulata exclusively on the abaxial (lower) surfaces.  Nevertheless, the characteristic white stippling was easily visible on the leaves and gave immediate clue to their presence.

Photo Details: Canon 50D w/ MP-E 65mm 1-5X macro lens (ISO 100, 1/200 sec, f/13), Canon MT-24EX flash w/ Sto-Fen + GFPuffer diffusers. Typical post-processing (levels, minor cropping, unsharp mask). Photo 1 taken at 1X, photos 2 through 6 taken at or near 5X.

REFERENCES:

Ajmat, M. V., S. G. Bado, M. A. Coviella and M. J. Pannuzio. 2003. Aspectos morfológicos, biológicos y daño de Gargaphia lunulata (Mayr) 1865 (Heteroptera: Tingidae) sobre Passiflora caerulea L. (Passifloraceae). Boletin Sanidad Vegetal Plagas 29:339–346.

Guilbert, É. 2005. Morphology and evolution of larval outgrowths of Tingidae (Insecta, Heteroptera), with description of new larvae. Zoosystema27(1):95–113.

Haene, E. and G. Aparicio.  2007.  100 Trees of Argentina. Editorial Albatros, Buenos Aires, República Argentina, 128 pp.

Kogan, M.  1960.  Corythaica cyathicollis (Costa, 1864), aspectos sistemáticos, biológicos e econômicos (Hemiptera, Tingidae). Memorias Instituto Oswaldo Cruz 58(1):59–88.

Montemayor, S. and M. del Carmen Coscarón. 2005. List of Argentinian Tingidae Laporte (Heteroptera) with their host plants. Zootaxa 1065:29–50.

Neal, J. W., Jr. and C. W. Schaefer. 2000. Chapter 4. Lace Bugs (Tingidae), pp. 85–137. In:C. W. Schaefer and A. R. Panizzi (Eds.). Heteroptera of Economic Importance, CRC Press LLC, Boca Raton, 828 pp.

Copyright © Ted C. MacRae 2011

Big, Bold, and Beautiful

/ Ted C. MacRae / 12 Comments

Cicindela formosa generosa | Castlewood State Park, Missouri.

Last fall I took my younger daughter to the Al Foster Trail on the western side of Castlewood State Park, just a few miles down the road from my house.  As we walked the trail through typical bottomland forest next to the Meramec River, I noticed what appeared to be open ground on a rise to the north of the trail.  When I went up to investigate, I saw a rare sight for Missouri—dry sand!  Obviously a deposit from some past flood event, the post oaks established around its perimeter and native warm season grasses sparsely dotting its interior suggested it had been laid down many years ago.  Such sights were likely common along the big river systems of pre-settlement Missouri, as natural flooding cycles laid sand deposits up and down the river courses, each deposit gradually succumbing to vegetation as new deposits were laid down elsewhere.  Today, with channelization and levees for flood control, the Missouri and Mississippi Rivers are just narrow, hemmed-in shadows of their former selves, unable to lay down such deposits in most years until, at last, catastrophic flooding occurs on a grand scale (as is occurring now).  Feeding into the Mississippi River just south of the Missouri River is the Meramec River—as the state’s only still-undamned undammed river system, it still has opportunity on occasion to lay down these interesting dry sand habitats.

The dark brown coloration of this rather ''dirty'' individual is typical of most Missouri populations.

When I see dry sand habitats in Missouri, three tiger beetle species immediately come to mind—Cicindela formosa (big sand tiger beetle), C. scutellaris (festive tiger beetle), and Ellipsoptera lepida (ghost tiger beetle).  My colleague and co-cicindelophile Chris Brown and I have spent many a weekend traveling up and down the state’s river systems with these species in mind.  None of them are rare in the state, but their fidelity to deep, dry sand habitats also makes them by no means common.  It is always cause for celebration when a new site is discovered for one of these species somewhere in Missouri.  Thus, it was in anticipation of one (or more) of these species that I returned to the spot last week on the first truly gorgeous spring day of the season.  Could it really be that, after ten years of searching for these species throughout the state, I would find a population just a few miles down the road from my house?!

A number of individuals in this population show traces of the bright coppery red coloration more typical of nominotypical populations west of Missouri.

Walking onto the site, I began to see tiger beetles immediately.  However, they were Cicindela tranquebarica (oblique-lined tiger beetle), a common species in Missouri that enjoys not only dry sand habitats, but also wet sand, wet mud, dry clay, and even concrete habitats—hard to get excited about such a habitat slut!  Nevertheless, within minutes I began seeing more robust beetles that were unmistakably big sand tigers.  Big, bold, and beautiful, the beetles were wary in the late afternoon heat and quickly launched into their powerful escape flights that ended comically some 20 yards away with a characteristic bounce and a tumble.  Such behavior might seem to make them impossible to photograph, but I’ve been at this for awhile and know their behavior pretty well—a slow, cautious approach, crouching carefully at the right distance, and crawling deliberately on elbows and knees while peering from behind the camera until it shows up in the lens set to 1:3 (one-third life size).  Then it’s a matter of even more slowly closing the distance and scooting around to get the desired angles and composition.  Move slowly enough and they’ll forget you’re there and resume normal behavior—you’ll be richly rewarded with views of foraging, stilting, and other classic tiger beetle behaviors.

Coloration and markings may seem conspicuous but provide excellent camouflage against the pebbley-sand substrate.

Most of the big sand tiger beetle populations we have found in Missouri are typical of the eastern subspecies C. formosa generosa, distinguished from other named subspecies by the dark brown dorsal coloration and thick white markings that are separate dorsally and joined along the outer edges of the elytra (Pearson et al. 2006).  This subspecies is predominantly midwestern and northeastern in distribution, while the typically bright coppery-red individuals assigned to the nominotypical subspecies are found further west in the Great Plains.  There are, however, certain populations in Missouri that show more or less suffusion of coppery-red coloration.  This is typically explained as hybrid influence, as Missouri lies on the western edge of the distributional range of subspecies generosa.  However, we have only seen these coppery-red indications on the eastern side of Missouri, while populations on the western side of the state along the Missouri River exhibit typical dark brown coloration.  The population here in St. Louis Co. is the third population we have found to show this coppery-red influence, and in fact most of the individuals I saw exhibited greater or lesser amounts of this coloration.  My personal belief is that there is no genetic basis for this subspecific distinction, but that the differences in color are instead related to conditions of the soil in which they live—possibly pH.  Sand habitats in the eastern United States are typically acidic, while alkaline soils abound in the Great Plains (formerly a vast sea bottom).  Hey, it’s a thought!

Big sand tiger beetles remain one of my favorite beetle species in Missouri.

The combination of striking coloration and bold white markings exhibited by big sand tiger beetles might seem to make them quite conspicuous and vulnerable to predation—especially in the open, sparsely vegetated areas that they inhabit; however, against the textured sandy substrates on which they are found they are almost impossible to detect until they move.  I’ve learned not to try to see them first and sneak up on them, as this is a lesson in futility.  Rather, I simply walk through an area and fix my sights on individuals as they take flight, watching them as they fly and eventually land and then sneaking up to the spot where I saw them land.  I generally need to stop about 8-12 feet out and study the spot carefully to pick them out, and then I can continue sneaking up on them.

Photo Details: Canon 50D w/ 100mm macro lens (ISO 160, 1/200 sec, f/16), Canon MT-24EX flash w/ DIY oversized concave diffuser. Typical post-processing (levels, minor cropping, unsharp mask).

REFERENCES:

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 2011

Feasting on the bounty

/ Ted C. MacRae / 16 Comments

Brood XIX periodical cicadas were not the only insects appearing en masse last week at Sam A. Baker State Park in Missouri’s southeastern Ozark Highlands.  As I walked the upland trail, I thought I felt ‘raindrops’ for awhile before realizing that it was frass.  Little pieces of fresh young leaves littered the trail around me, and I realized that an outbreak of caterpillars was hammering the oak trees in this forest.  Unlike the cicadas, which were encountered primarily in the bottomland forest along Big Creek, the rain of poop was restricted to the uplands.  Not surprisingly, I saw caterpillar hunters, Calosoma spp. (family Carabidae—the real Carabidae, not the tiger beetle Carabidae that I’ve begrudgingly had to accept) about as abundantly as I’ve ever seen them.  At first I didn’t notice them until I would scare one up, then spend several frustrating minutes trying to photograph a beetle that just would not stop running.  I tried a few and gave up—after all, they’re just ground beetles (i.e., real ground beetles).  Eventually, I realized that if I noticed them before they noticed me, I could sneak up on them and have my way with them (photographically speaking, that is).  I even found that I could preen nearby leaves and sticks for composition if I did it carefully enough.  Here are a couple of my favorite shots on the day.

I would presume these to represent the fiery searcher, Calosoma scrutator, but apparently C. wilcoxi is similar in appearance.  According to comments by several BugGuide users, C. scrutator is larger (25mm or more in length), has more elongated mandibles and head, and the color of the central purple area of the pronotum is more intense.  Based on those comments, I would say the two individuals in these photographs are C. scrutator.  However, they also note some differences in temporal occurrence that don’t seem to support that.  Moreover, the many individuals I saw that day ranged in size from these larger individuals to some notably smaller ones.

Copyright © Ted C. MacRae 2011

Love is in the air!

/ Ted C. MacRae / 14 Comments

My first tiger beetle photograph of the season. There’s nothing more adorable than Spring love!

Cicindela tranquebarica (oblique-lined tiger beetle) | St. Joe State Park, Missouri

Photo details: Canon 50D w/ 100mm f2.4 macro lens (ISO 160, 1/200 sec, f/16), Canon MT-24EX twin flash w/ DIY oversized concave diffuser.

Copyright © Ted C. MacRae 2011

“They’re baaaaack!”

/ Ted C. MacRae / 24 Comments

The recent run of seemingly interminable rains and HF4 tornadoes may have delayed the Annual-Birthday-First-Bug-Collecting-Trip-of-the-Year™, but it could not cancel it.  On Thursday this week, for the first time since the same time last week, a strange ball of hot gas appeared in the sky, temperatures tickled the 70°F mark, and the only moisture we encountered was already on the ground.  The weatherman said several days ago it would happen, so I put my faith in his word and made plans with my dad to do what I had planned to do last week – officially open the 2011 bug collecting season.  It was a marvelous day in which many interesting stories unfolded, one of which I’ve heard (literally) a few times already.

One of our stops was Sam A. Baker State Park in southeastern Missouri.  My original reason for coming here involved dead wood retrieval (success) and rattlesnakes (failure, though with a consolation prize – more later).  As we were walking the trail in the bottomland forest along Big Creek, I noticed all these holes in ground.  At first I assumed a group of hikers wielding their fashionable trekking poles had gone before us and left their mark in the muddy, recently flooded soil, but the holes were just too numerous and not all perfectly round.  I had just commented to my dad, “What the heck caused all these holes?”, when I saw the culprit – a fully grown periodical cicada nymph crawling on the ground looking for a tree to climb and begin life as one of the noisiest insects on earth.  I looked around and saw another one, and another… they were everywhere!  Boy, are we gonna be in for it this year!

Missouri and several other Midwestern states will be hosting periodical cicada Brood XIX—the Great Southern Brood!  All four of the 13-year species (Magicidada tredecassini, M. tredecula, M. tredecim, and M. neotredecim) participate in this brood, the largest of the 13-year broods by geographical extent, and occur in Missouri in variously overlapping ranges.  Magicicada tredecim and M. neotredecim are the two most common species in the Ozark Highlands across the southern part of the state, so the nymphs shown here likely represent one or both of those species.

I remember well the previous two appearances of brood XIX in Missouri in 1998 and 1985, when beating for buprestids during May and June was an exercise in futility due to every tree branch literally dripping with these bumbling, screeching insects (too bad I never find buprestids dripping from tree branches like this).  Those that didn’t land flapping clumsily on the sheet ended up desperately clinging to my head or flying into my face.  If swatting at these flying bullets wasn’t maddening enough, the ceaseless, droning, omnipresent cacophony of their singing was almost enough to send me to the local psycho ward begging for admittance.

I think I’ll skip trying to use the beating sheet this year.

Copyright © Ted C. MacRae 2011