Reduviidae

Assassin bugs, ambush bugs, cone-nose bugs, thread-legged bugs. About 2,500 species worldwide, best represented in tropical regions. Predominantly predaceous on other arthropods; some species feed on vertebrate blood.

Best of BitB 2013

/ Ted C. MacRae / 14 Comments

Welcome to the 6th Annual “Best of BitB”, where I pick my favorite photographs from the past year. Like last year, 2013 was another year of heavy travel. For work I did my annual tour of soybean field sites throughout Argentina during late February and early March, then cranked it up for my own field season with frequent travel to sites in Illinois and Tennessee from May to October. In the meantime I spent a week at company meetings in Las Vegas in August, toured field sites across the southeastern U.S. for two weeks in September, visited Argentina again in October to finalize research plans for their upcoming season, and finished off the travel year by attending the Entomological Society of America (ESA) Meetings in Austin, Texas during November. On top of all this, I managed to slip in two of the best insect collecting trips I’ve had in years, with 10 days in northwestern Oklahoma in early June and another 10 days in California, Nevada, Utah, and Colorado during late August, and I got to play “visiting scientist” during short trips to Montana State University in late July and the Illinois Natural History Survey in late October! Of course, during my brief interludes at home I wasn’t sitting still, giving entomology seminars to several local nature societies and hosting two ESA webinars on insect photography. Needless to say, come December I was more than ready to spend some quite time at home (well, except for hiking most weekends) and am happy to report that I’ve successfully become reacquainted with my family and office mates. It’s a peripatetic life—and I wouldn’t have it any other way!

Okay, let’s get down to business. Here are my favorite BitB photographs from 2013. This year was less about learning new techniques as it was about refining the techniques I’ve found most useful for the style I’ve chosen as a photographer, i.e., hand-held, in situ field shots that (hopefully) excel at both natural history and aesthetic beauty. Links to original posts are provided for each photo selection, and I welcome any comments you may have regarding which (if any) is your favorite and why—such feedback will be helpful for me as I continue to hone my craft. If you’re interested, here are my previous years’ picks for 2008, 2009, 2010, 2011, and 2012. Once again, thank you for your readership, and I hope to see you in 2014!

Tremex columba, female ovipositing | Sam A. Baker State Park, Missouri

Tremex columba female drilling for oviposition into hardwood trunk | Sam A. Baker State Park, Missouri

From Ovipositing Pigeon Horntail (posted 6 Jan). I like this photo for the combination of vibrant, contrasting colors between the wasp and moss-covered wood and the visualization it provides of the remarkable depth to which this wasp will insert its ovipositor into solid wood!

Eurhinus cf. adonis on Solidago chilensis | Chaco Province, Argentina

Eurhinus cf. adonis on Solidago chilensis flowers | Chaco Province, Argentina

From Giving me the weevil eye! (posted 28 Apr). While a little soft, the color combination is pleasing and the pose taken by the beetle almost comically inquisitive.

Helicoverpa gelotopeon feeding on soybean pod | Buenos Aires Prov., Argentina

Helicoverpa gelotopeon feeding on soybean pod | Buenos Aires Prov., Argentina

From Bollworms rising! (posted 30 Mar). This is the first photo of an economic pest that has made one of my “Best of BitB” lists. The two holes in the soybean pod, one with the caterpillar and its head still completely inserted, visualizes how the feeding habits of these insects can so dramatically affect yield of the crop.

cf. Eremochrysa punctinervis | Gloss Mountains, Major Co., Oklahoma

cf. Eremochrysa punctinervis | Gloss Mountains, Major Co., Oklahoma

From “Blue-sky” tips and tricks (posted 1 July). Insects with a lot of delicate detail and long, thin appendages are especially difficult to photograph against the sky due to wind movement. See how I dealt with the antennae of this delicate lacewing without resorting to the standard black background typical of full-flash macrophotography.

Cicindela scutellaris lecontei x s. unicolor

Cicindela scutellaris lecontei x s. unicolor intergrade | Holly Ridge Natural Area, Stoddard Co., Missouri

From The Festive Tiger Beetle in Southeast Missouri (posted 25 Oct). I like this photo a lot more now than I did when I first took it. Its shadowy feel and the beetle “peering” from behind a leaf edge give a sense of this beetle’s attempts to hide and then checking to see if the “coast is clear”

Batyle suturalis on paperflower (Psilostrophe villosa) | Alabaster Caverns State Park, Woodward Co., Oklahoma

Batyle suturalis on Psilostrophe villosa flowers | Alabaster Caverns State Park, Woodward Co., Oklahoma

From Tips for photographing shiny beetles on yellow flowers (posted 10 Aug). “Bug on a flower” photos are a dime a dozen, but shiny beetles on yellow flowers with natural sky background can be quite difficult to take. All of the techniques for dealing with the problems posed by such a photo came together nicely in this photo.

Agrilus walsinghami | Davis Creek Regional Park, Washoe Co., Nevada

Agrilus walsinghami | Davis Creek Regional Park, Washoe Co., Nevada

From Sunset for another great collecting trip (posted 1 Sep). This photo is not without its problems, with a little blurring of the backlit fuzz on the plant, but the placement of the sun behind the subject’s head and resulting color combination make it my favorite in my first attempts at achieving a “sun-in-the-sky” background with a true insect macrophotograph.

A tiny male mates with the ginormous female.

Pyrota bilineata on Chrysothamnus viscidflorus | San Juan Co., Utah

From Midget male meloid mates with mega mama (posted 8 Nov). Another blue-sky-background photograph with good color contrast, its real selling point is the natural history depicted. with some of the most extreme size dimorphism among mating insects that I’ve ever seen.

Phymata sp.

Phymata sp. on Croton eleagnifolium foliage | Austin, Texas

From ESA Insect Macrophotography Workshop (posted 13 Nov). The oddly sculpted and chiseled body parts of ambush bugs makes them look like they were assembled from robots. Contrasting the body against a blue sky gives a more unconventional view of these odd beasts than the typical top-down-while-sitting-on-a-flower view.

Fourth attempt - holding detached pad up against sky for cleaner background.

Moneilema armata on Opuntia phaecantha | Alabaster Caverns State Park, Woodward Co., Oklahoma

From Q: How do you photograph cactus beetles? (posted 24 Nov). Photographing cactus beetles requires patience, persistence, long forceps, and strong forearms. Natural sky provides a much more pleasing background than a clutter of cactus pads and jutting spines.

I hope you’ve enjoyed this 2013 version of “Best of BitB” and look forward to seeing everyone in 2014.

Copyright © Ted C. MacRae 2013

ESA Insect Macrophotography Workshop

/ Ted C. MacRae / 9 Comments

Today is the last day of the Entomological Society of America (ESA) Annual Meeting in Austin, Texas, and it has been an action packed week for me. Annual meetings such as this serve several purposes. In addition to seeing talks on a variety of subjects—in my case covering subjects ranging from insect resistance management to scientific outreach to beetle systematics—they also offer the chance to establish new connections with other entomologists that share common interests and reinforce existing ones. Of course, a major part of my interest in entomology revolves around insect macrophotography, and in recent years ESA has begun to cater to the entomological photographer contingent within the society. Last year’s meetings featured a macrophotography symposium titled, “Entomologists Beyond Borders” (for which I was one of the invited speakers), and this year featured an Insect Macrophotography Workshop led by Austin-based entomologist/photographer Ian Wright. Having done this for a few years now I figured a lot of the workshop might be review for me, but I still have much to learn and am willing to accept new ideas from any source. Besides, the workshop involved a field trip to a local habitat to try out our insect photography skills, and for a field junkie like me time in the field at an otherwise all-indoor event spanning close to a week is always welcome. The location of the meetings in Austin this year made this possible, as even in mid-November there still remain insects out and about that can be photographed if the weather cooperates (and it did).

This will be a somewhat different post than what I usually post here. Rather than featuring photos of a certain species and using them as a backdrop for a more detailed look at their taxonomy or natural history, I’m just going to post all the photos that I ended up keeping from the field trip portion of the workshop with just a comment or two about each. We went to the city’s nearby waste-water treatment facility, the grounds of which are wild and woolly enough to provide habitat for insects, and spent about an hour and a half seeing what we could find. For myself, it was a chance to photograph some insects I’ve not normally tried to photograph (i.e., dragonflies, ambush bugs) and get more practice on my blue sky technique. I did appreciate the chance to spend some time talking to Ian during while we traveled to the site and back, and I also ended up helping other participants with their camera equipment questions and technique suggestions. With that, here are the photos I took—I’ll be curious to see what readers think of this post format versus my more typical style.

Micrutalis calva

Micrutalis calva (Hemiptera: Membracidae) on silverleaf nightshade (Solanum elaeagnifolium).

Micrutalis calva

This species of treehopper is restricted to herbaceous plant hosts.

Anax junius

Anax junius (Odonata: Aeshnidae), one of the darner species of dragonfly.

Anax junius

This adult was perched on a dead twig tip and seemed to be “asleep.”

Anax junius

I clipped the perch and held it up for these “in-your-face” shots – it then awoke with a start and flew off.

Phymata sp.

Phymata sp. (Hemiptera: Reduviidae), one of the so-called “jagged ambush bugs.”

Phymata sp.

Formerly a separate family, ambush bugs are now combined with assassin bugs (family Reduviidae).

Acmaeodera flavomarginata

Acmaeodera flavomarginata (Coleoptera: Buprestidae).

Acmaeodera flavomarginata

This is one of a few species of jewel beetle in the southcentral US that are active during the fall.

Mecaphesa sp.

Mecaphesa sp. (Araneae: Thomisidae), one of the crab spiders

Mecaphesa sp.

Cryptic coloration allows the spider to lurk unseen by potential insect prey visiting the flower.

Gratiana pallidula

Gratiana pallidula (Coleoptera: Chrysomelidae) on silverleaf nightshade (Solanum eleagnifolium).

Gratiana pallidula

A type of tortoise beetle, adults “clamp” down against the leaf as a defense against predators.

Copyright © Ted C. MacRae 2013

Bee Assassin on Coneflower

/ Ted C. MacRae / 6 Comments
Bee assassin (Apiomerus spissipes) on coneflower (Echinacea sp.) | Gloss Mountain State Park, Major Co., Oklahoma

Apiomerus spissipes? on coneflower (Echinacea sp.) | Gloss Mountain State Park, Major Co., Oklahoma

While looking for longhorned beetles on prickly pear cactus (Opuntia phaecantha) at Gloss Mountains State Park, I saw a coneflower that didn’t look quite right—there was nothing on the top, but there seemed to be something on the underside. I knelt down cautiously and peered underneath the blossom to find this bee assassin (family Reduviidae, genus Apiomerus) lurking under the petals. As a collector with eyes always looking for signs of insects, I’ve trained myself to look for both the obvious and the non-obvious, yet  this brightly colored insect still almost completely escaped my notice. I can imagine that a bee with little room in its mind for anything but collecting pollen would be easy pickings for such a stealthy predator.

Apiomerus spissipes

The coloration of this individual seems to best match specimens representing the species Apiomerus spissipes, which ranges broadly and abundantly across the Great Plains (Berniker et al. 2011). The location of Gloss Mountain State Park in western Oklahoma places it almost smack in the middle of the recorded distribution for this species, which is largely replaced further east by the closely related but generally darker A. crassipes. Interestingly, very few Oklahoma specimens were available for examination by Berniker and colleagues during their study, a fact that once again demonstrates the need for continued collecting in even “well-collected” states like Oklahoma.

REFERENCE:

Berniker, l., S. Szerlip, D. Forero & C. Weirauch. 2011. Revision of the crassipes and pictipes species groups of Apiomerus Hahn (Hemiptera: Reduviidae: Harpactorinae). Zootaxa 2949:1–113.

Copyright © Ted C. MacRae 2013

Best of BitB 2012

/ Ted C. MacRae / 23 Comments

Welcome to the 5th Annual “Best of BitB”, where I pick my favorite photographs from the past year. 2012 was one of the most intensive travel years I’ve ever had—I spent 8 weeks in Argentina from February through April, made separate trips to Puerto Rico and Arkansas in May (bracketing a personal week in California), traveled almost weekly to Illinois and Tennessee from June to September (interrupted by a personal week in Florida in July), toured the southeastern U.S. (Arkansas, Louisiana, Mississippi and Georgia—great food!) in early September, chased tiger beetles in Oklahoma, Texas and Arkansas in late September, went back to Argentina for a week in October, and capped off the travel year by attending the Entomological Society of America Annual Meetings in Knoxville, Tennessee (for the first time in more than 10 years!)—whew! While many would cringe at such a travel load, I am among the lucky few who actually get paid for doing something that is also my hobby—entomology! This gives me ample opportunity to further hone my photography skills (nine of the 13 photos I’ve selected below were actually taken while I was on business travel), resulting in two key accomplishments this year—my first ever photography talk at the ESA’s insect photography symposium and my first commercial sales (look for the BitB commercial site to go online in 2013).

Enough blather! Here are my favorite BitB photographs from 2012. Click the link in the text below the photo to see the original post. I would greatly appreciate knowing if you have a favorite (and why)—your feedback will be enormously helpful to me as I continue to learn and develop as a photographer.  For those interested, here are my previous year picks for 2008, 2009, 2010 and 2011. And, as always, thank you for your readership!

Spintherophyta (?) sp. in flower of Abutilon pauciflorum | Buenos Aires, Argentina

From  (posted 2 Feb). One of my 2012 learnings was that sometimes a photograph that is not so close is more effective than one that is as close as possible. In one of my earlier attempts at “not-so-close” macrophotgraphy, the soft colors of the flower compliment the brash shininess of the tiny leaf beetle that has been feeding on its pollen. Pink lines lead the eye directly to the subject and create a pleasing composition, and pollen grains stuck to the beetle—a distraction in some situations—add to the miniature natural history story of the photo.

Apiomerus flavipennis with stink bug prey and kleptoparasitic flies | Chaco Province, Argentina

From  (posted 11 Mar). I selected this photo solely for the complex natural history story drama it shows—stink bug (Piezodorus guildenii) feeding on soybean becomes prey of an assassin bug (Apiomerus flavipennis), with volatiles from the chemicals it emitted in a vain attempt to defend itself serving as cues to kleptoparasitic flies (families Milichiidae and Chloropidae) that benefit from the assassin bug’s labors.

Planthopper nymph | Buenos Aires Province, Argentina

From  (posted 26 Mar). Another learning that I began putting into practice in 2012 was the use of low perspective for compositional impact. The cryptic coloration of this planthopper nymph (family Fulgoridae) made it almost invisible on the branch on which it was sitting when viewed from a normal “top-down” human perspective. Getting “down under” it, however, brought the nymph to life and emphasized its unusual form.

Megabaris quadriguttatus | Corrientes Province, Argentina

From  (posted 12 Apr). I spent much of 2012 working on the “blue sky background” technique, with these weevils from northern Argentina representing one of my better attempts. Macrophotography of insects with a blue sky background involves setting exposure, ISO, and aperture to achieve two separate exposures—full flash illumination of the subject for maximum depth-of-field, and ambient light from the sky to create a clean, uncluttered, natural-looking background. In this shot I managed to achieve an almost ideal shade of blue to compliment the wild black, white and red colors of the beetles. (My one criticism of the photo is having clipped one of the beetle’s feet.)

Bombylius sp. cf. mexicanus | Scott Co., Missouri

From  (posted 16 May). This photo is unusual if nothing else. Focus, lighting, depth-of-field, and composition are all better than can be hoped for in a single shot, but the subject—perfectly alive—is in a most unusual position. Read the original post to find out how this happened.

Perisphaerus sp. (a pill roach) | Vietnam (captive individual)

From  (posted 27 May). White-box photography is an excellent technique for clean, uncluttered photographs of insects, but it also isolates them from their natural surroundings and limits their natural history appeal. The best white-box photos are those that highlight a key feature or behavior of the subject—in this case a pill roach’s comically conglobulating defensive posture.

Micronaspis floridana (Florida intertidal firefly) larva | Pinellas Co., Florida

From  (posted 31 July). Here is another photo whose back story played a big part in its selection. This firefly larva not only represents a rare Florida-endemic species but was also first seen by my then 12-year old nephew, who willingly accompanied me through a dark, spooky salt marsh in the middle of a humid Florida night to see what he could learn. The lesson here for budding natural historians (and old-timers like me) cannot be overstated!

Arctosa littoralis (beach wolf spider) | Lewis Co., Missouri

From  (posted 23 Aug—prelude to  posted 28 Aug). Those who follow this blog know of my obsession with close-up portraits, and while tiger beetles are the subjects I most commonly photograph in this manner, I am always on the lookout for good subjects in other taxa. This wolf spider “face” almost looks human, with “two” eyes, two “nostrils” and a shiny upper lip above huge (albeit hairy) buck teeth! It’s enough fill-the-frame spidery goodness to melt (or explode) the heart of even the most ardent arachnophobe!

Anticarsia gemmatalis (velvetbean caterpillar) egg on soybean leaf

From Life at 8X—Guide to lepidopteran eggs on soybean (posted 3 Sep). “Life at 8X” was a new series I introduced this year, featuring insects photographed at magnifications testing the upper limit of my equipment and photographic skills. Diffraction is the chief difficulty with magnifications as high as this and is the primary flaw in the above photograph. Nevertheless, such view of a moth egg on the underside of a soybean leaf provides a spectacular view of the otherwise unseen micro-world that lives right beneath our noses.

Megacyllene decora (amorpha borer) on snakeroot flowers | Mississippi Co., Missouri

From  (posted 12 Sep). This second example of “blue sky background” was taken later in the year and was considerably more difficult to capture than the first because of the larger size of the subject and resulting need for a longer focal length macro lens. Getting a well-lit, focused, and composed image with a desirable shade of blue in the background depended not only on finding the proper camera settings, but also secure body and camera bracing techniques for this completely hand-held shot.

Cicindelidia politula politula (Limestone Tiger Beetle) | Montague Co., Texas

From  (posted 28 Sep). I will go ahead and say it—this is my favorite photograph of 2012. As discussed under the first entry, panning back from the subject can allow for some very interesting compositions. This photo combines charismatic pose by a wary subject with panning back and low perspective to create an image that scores high in both natural history and aesthetic appeal.

Calosoma sayi (black caterpillar hunter) | New Madrid Co., Missouri

From Black is beautiful! (posted 7 Nov). Of course, close-as-possible can also be used to create striking photos, especially if the subject exhibits features that are best seen up close. Anything with jaws fits the bill in my book, and highlighting the mandibular sculpturing of this caterpillar hunter (a type of ground beetle) required precise angling of the flash heads for maximum effect.

Cicindela repanda (Bronze Tiger Beetle) | St. Louis Co., Missouri

From  (12 Nov). This final selection is not a rare species, but it is as close as I have come to what I consider the “perfect” tiger beetle macrophotograph—a close, low angle, lateral profile of an adult in full-stilt posture (a thermoregulatory behavior), well lit, perfectly focused, and with a dynamic but pleasingly blurred background. It’s a perfect storm of a photo that took the better part of two hours to achieve—rarely do all of these elements come together in a hand-held photograph of an unconfined tiger beetle in its native habitat.

Well, there you have it. I hope you’ve enjoyed my selections, and again please do let me know if you have a personal favorite. See you in 2013!

Copyright © Ted C. MacRae 2012

Lord of the flies!

/ Ted C. MacRae / 22 Comments

I happened upon a rather interesting scene last week in a soybean field in northern Argentina (Chaco Province). This assassin bug (family Reduviidae) had captured and was feeding on an adult stink bug of the species Piezodorus guildinii—an important pest of soybean in Argentina and Brazil (where it is known by the common names “chinche de la alfalfa” and “chinche verde pequeño”, respectively). Assassin bug predation is always interesting enough itself, but what made this scene especially fascinating was the large congregation of flies surrounding and even crawling upon the predator and its prey. I had not witnessed something like this before, but it seemed clear to me that the flies were engaging in kleptoparasitism—i.e, stealing food. I’ve gotten into the habit of keeping a full set of extension tubes mounted on the camera with my 100mm macro lens—this not only provides the most useful (for me) range of magnification but also serves as a convenient and easy-to-use field microscope. Through the viewfinder I could see that there were at least two markedly different types of flies involved—more abundant, small, brown flies that I presumed (incorrectly, as it turns out) to be some type of drosophilid (vinegar fly), and a few larger, black flies that were completely unfamiliar to me. The flies were apparently feeding on fluids from the stink bug prey but also crawled all over the assassin bug as it fed. The assassin bug seem unencumbered in its feeding by the presence of the flies, but periodically it would slowly wipe its forelegs over its head to dislodge flies that had settled onto it. Just as quickly as they flew away, however, they crawled back.

The assassin bug, on the other hand, I recognized as very likely a species of Apiomerus—a large, exclusively New World genus known in North America as “bee killers” for their habit of sitting on flowers and ambushing visiting bees for prey. The prey selection behaviors of these insects, however, are more generalist than the name implies, as can be seen by these photographs. To verify my generic ID and possibly obtain a species ID, I sent some of these photos to Dimitri Forero at the Heteropteran Systematics Lab at University of California-Riverside. Dimitri is revising portions of Apiomerus (e.g., Berniker et al. 2011) and working on a general phylogenetic hypotheses for the genus. In the past he has been quite helpful in fielding questions from me about these bugs, and within a few hours Dimitri replied to inform me that the assassin bug was, indeed, a member of the genus Apiomerus, likely representing the common, widespread species A. lanipes (ranging from Panama to Argentina), based on its coloration, locality, and relative size. Update 12 March, 3:07 pm—After seeing the last photo in this post (which I did not send to him initially), Dimitri wrote to say the ventral abdominal pattern was not characteristic of A. lanipes. He asked about its size, to which I replied that it was about the same length but maybe a little less robust than A. crassipes (eastern North America). He later added, “I now think that this is A. flavipennis Herrich-Schaeffer, 1848. It is very similar to A. lanipes, but a lot smaller (lanipes is really robust), and with the abdomen with black and white patches, whereas in lanipes the abdomen is always black. I checked some series of specimens that I have here and, I am pretty sure now of the ID. I have material from Argentina as well. In some specimens that coloration of the corium varies, but the original description says it is yellow with a “hairy” pronotum, which fits very nicely your photos.” Apiomerus flavipennis is known from Argentina and Southern Brazil only.

Quite unexpectedly, Dimitri also noted that at least some of the flies could belong to the family Milichiidae. He first became aware of these flies after seeing a photograph of Apiomerus showing something similar and suggested Milichiidae online as a possible source for more information. This remarkably informative  website by milichiid expert Irina Blake, who dubs species in the family as “freeloader flies”, is a model for how websites dealing with obscure insect taxa should be organized and populated (and features on the home page a great photo of ant-mugging flies taken by our favorite myrmecophile). At any rate, I forwarded my photos to Irina and within minutes received her response that the bigger black flies most probably represent the cosmopolitan Milichiella lacteipennis and the smaller flies a species of the family Chloropidae (of “dog pecker gnat” fame) in the subfamily Oscinellinae, noting that she has seen similar (or the same?) chloropids in other photos as well engaging in kleptoparasitism.

Not long after receiving the first reply from Dimitri, I got another message from him with a link to a very interesting paper by Eisner and colleagues (1991), who recorded freeloader flies in Florida preferentially attracted to stink bugs and leaf-footed bugs (family Coreidae) being preyed upon by the orb-weaving spider Nephila clavipes. Olfactory stimuli were already suspected to be involved in attraction of milichiids and also chloropids (Sivinski 1985); however, Eisner et al. (1991) experimentally demonstrated that milichiid attraction was tied to specific components of defensive sprays in several pentatomid and coreid species (including P. guildenii, the prey species in this series of photographs). The defensive sprays of the bugs were generally ineffective at preventing predation by the spiders (and apparently this is the case for A. lanipes and other reduviids as well), thus serving as a signal to milichiids and chloropids not only of the presence of a food source but perhaps also assisting search for mates in a density dependent fashion (Sivinsky 1985). Milichiid attraction to hymenopteran prey, richly endowed with integumental glands themselves, has also been documented; the Eisner study raises the question whether these types of prey are also detected from chemical cues.

REFERENCES:

Berniker, L., S. Szerlip, D. Forero and C. Weirauch. 2011. Revision of the crassipes and pictipes species groups of Apiomerus Hahn (Hemiptera: Reduviidae: Harpactorinae). Zootaxa 2949:1–113.

Eisner, T., M. Eisner & M. Deyrup. 1991. Chemical attraction of kleptoparasitic flies to heteropteran insects caught by orb-weaving spiders. Proceedings of the National Academy of Sciences of the United States of America 88:8194–8197.

Sivinski, J. 1985. Mating by kleptoparasitic flies (Diptera: Chloropidae) on a spider host. Florida Entomologist 68(1):216–222.

Copyright © Ted C. MacRae 2012

Assassin ate

/ Ted C. MacRae / 20 Comments

IMG_1146_1200x800

I came upon this interesting scene last month while hiking through Allen David Broussard Catfish Creek Preserve State Park, which preserves some of the highest quality remnants of sand scrub habitat on the Lake Wales Ridge of central Florida. The spider seems to be Peucetia viridans (green lynx spider), widespread across the southern U.S. and distinguished by its bright transparent green color with red spots and black spines (Emerton 1961). These largest of North American lynx spiders hunt diurnally on low shrubs with an agility excelled only by the jumping spiders (Salticidae) and aggressively attack their insect prey. In this case, the prey is one of the so-called “bee assassins” of the genus Apiomerus (Hemiptera: Reduviidae). The common and generic names of these insects both derive from their habit of preying upon bees, not only on flowers but also by ambushing them at nest entrances, although other insects are preyed upon as well. Ironically, this particular assassin himself got ate.

An interesting situation was uncovered while I tried to determine which species of Apiomerus was represented by the prey. By virtue of its pale ventrals with the front and hind margins black, it keys to A. spissipes in a literature-based key to Florida Reduviidae (Bierle et al. 2002) – one of two species considered widely distributed across the eastern U.S. In reality, however, it appears that this individual represents another species named almost 30 years ago but which remains officially undescribed. As explained in this BugGuide post by Daniel Swanson, the genus was revised by Berkeley grad student Sigurd Leopold Szerlip in partial fulfillment of the requirements for a Ph.D., who proposed a number of taxonomic acts including the description of 19 new species. Among these were eastern U.S. populations to which the name A. spissipes had been applied, with those in Florida being described as the new species “A. floridensis“. However, dissertations do not meet the criteria of publication according to Article 8 of the International Code of Zoological Nomenclature (ICZN 1999), and none of the dissertation was formally published. Thus, “A. floridensis” remains an invalid, unpublished name.  This is a most unfortunate situation, as Swanson considers the dissertation to be well done.  It is not only names, but important information about life histories and detailed genitalic studies that remain unavailable to the scientific community as well.  What are the nomenclatural impacts of this work remaining unpublished?  Is this as much a failure by the advising professor as by Szerlip himself?  What ethical considerations would need to be addressed in order for it to be published in absentia, or is this even possible?

Photo details: Canon 100mm macro lens on Canon EOS 50D (manual mode), ISO-100, 1/250 sec, f/13, MT-24EX flash 1/2 power through diffuser caps.

REFERENCES:

Bierle, S., E. Dunn, S. Frederick, S. Garrett, J. Harbison, D. Hoel, B. Ley and S. Weihman. 2002. A literature-based key to Reduviidae (Heteroptera) of Florida (assassin bugs, and thread-legged bugs). Unpublished manuscript, University of Florida, Department of Entomology and Nematolgy, Insect Classification ENY 4161/6166, 18 pp.

Emerton, J. H. 1961. The Common Spiders of the United States. Dover Publications, Inc., N.Y., xx + 227 pp.

International Commission on Zoological Nomenclature [ICZN]. 1999. International Code of Zoological Nomenclature, 4th Edition. The International Trust for Zoological Nomenclature, c/o Natural History Museum, London. xxix + 306 pp.

Szerlip, S. L. 1980. Biosystematic revision of the genus Apiomerus (Hemiptera: Reduviidae) in North and Central America. Unpublished Ph.D. thesis, University of California, Berkley, CA.

Copyright © Ted C. MacRae 2009

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Millipede assassin bug

/ Ted C. MacRae / 18 Comments

Ectrichodia crux

I continue the hemipteran theme begun in the last post with this photograph I took in South Africa below the Waterberg Range in Northern (now Limpopo) Province. I recognized them as members of the family Reduviidae (assassin bugs), and since to my knowledge species in this family are exclusively predaceous (except for the so-called “kissing bugs” of the mostly Neotropical subfamily Triatominae, large distinctive bugs that feed exclusively on vertebrate blood), I found what I took to be a case of scavenging on a dead millipede to be rather curious.  It had rained the previous evening, resulting in a burst of millipede (and insect) activity that night, and this scene was rather commonly encountered the following morning. Of course, appearances can be deceiving, and it turns out that I actually was witnessing predation – and a most unusual case at that.  The individuals in this photo represent Ectrichodia crux (millipede assassin bug), a common species in many parts of southern Africa.  Although nearly 500 species of assassin bugs are known from the region (Reavell 2000), E. crux is easily recognizable due to its large size (adults measure up to 22 mm in length), stout form, and coloration – shiny black, with a distinctive black cross incised on its dull yellow thorax and with yellow abdominal margins (Picker et al. 2002). The nymphs as well are distinctive – bright red with black wing pads. Clearly, these insects are advertising something.

Ectrichodia crux belongs to the subfamily Ectrichodiinae, noted for their aposematic coloration – often red or yellow and black or metallic blue, and as specialist predators of Diplopoda (Heteropteran Systematics Lab @ UCR).  Species in this subfamily are most commonly found in leaf litter, hiding during the day under stones or amongst debris and leaving their shelters at night in search of millipedes (Scholtz and Holm 1985). They are ambush predators that slowly approach their prey before quickly grabbing the millipede and piercing the body with their proboscis, or “beak.”  Saliva containing paralytic toxins and cytolytic enzymes is injected into the body of the millipede to subdue the prey and initiate digestion of the body contents, which are then imbibed by the gregariously feeding assassin bugs.

Millipedes employ powerful chemical defenses – primarily benzoquinones and sometimes hydrogen cyanide gas as well, which are discharged from specialized glands along the millipede’s body – to protect themselves from predation.  Thus, specialized predation of millipedes is a niche that has been exploited by relatively few predators, and little is known about the mechanisms used for circumventing these defenses. The recently reported millipede specialist, Deltochilum valgum (order Coleoptera, family Scarabaeidae), has been observed killing its prey by violently decapitating and disarticulating it before feeding on the body contents (Larsen et al. 2009, summary here); however, the exact manner by which the beetle avoids or withstands the millipede’s chemical discharges remains unknown.  For ambush predators such as Ectrichodia crux and other ectrichodiines, a strategy similar to that described for another millipede specialist predator, larvae of the phengodid beetle, Phengodes laticollis (order Coleoptera, family Phengodidae), might be employed. This species subdues its millipede prey by piercing thinner regions of the millipede’s integument (e.g., intersegmental membranes on the ventral surface) with its hollow sickle-shaped mandibles and apparently injecting gastric fluids that abruptly paralyze the millipede, thereby preventing it from discharging its gland contents (Eisner et al. 1998).  These undischarged benzoquinones remain confined to the glands and are prevented from diffusing into the body cavity by the glands’ impervious cuticular lining, thus allowing the phengodid larva to safely imbibe the liquified systemic contents of the immobilized millipede.

REFERENCES:

Eisner, T., M. Eisner, A. B. Attygalle, M. Deyrup and J. Meinwald. 1998. Rendering the inedible edible: Circumvention of a millipede’s chemical defense by a predaceous beetle larva (Phengodidae).  Proceedings of the National Academy of Sciences USA 95(3):1108–1113.

Larsen, T. H., A. Lopera, A. Forsyth and F. Génier. 2009. From coprophagy to predation: a dung beetle that kills millipedes. Biology Letters DOI:10.1098/rsbl.2008.0654.

Picker, M., C. Griffiths and A. Weaving. 2002. Field Guide to Insects of South Africa. Struik Publishers, Cape Town, 444 pp.

Reavell, P. E. 2000. The assassinbugs (Hemiptera: Reduviidae) of South Africa. http://oldwww.ru.ac.za/academic/departments/zooento/Martin/reduviidae.html#ectrichodiinae.

Scholtz, C. H. and E. Holm (eds.). 1985. Insects of Southern Africa. Butterworths, Durbin, South Africa, 502 pp.

Copyright © Ted C. MacRae 2009

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