IN SEARCH OF A HOLY GRAIL
By Arthur V. Evans
Last week, on a drizzly Thursday morning, I drove out to Cherry Orchard Bog Natural Area Preserve with my friends and colleagues Anne Wright and Paul Bedell. Straddling a power line right-of-way near the Sussex-Prince George County line, this preserve features a coastal plain acidic seep that supports an amazing assemblage of rare plants, some of which bloom in late summer. The Virginia Natural Heritage Program staff uses prescribed burns here to prevent trees, shrubs, and woody vines from choking this open wetland, and to restore and maintain this rare plant habitat. However, after yet another extended summer drought here in Virginia, surface water was nowhere in evidence.
My goal was to photograph and collect late summer beetles, while Anne and Paul focused their efforts on odonates (dragonflies and damselflies) and robber flies (Asilidae). Few beetles were out and about, so I strapped on my camera gear and knee-pads and turned my attention to photographing other insects and spiders.
Several tall and luxurious patches of sweet-scented joe pye weed, Eupatorium purpureum, grew smack dab in the middle of the power line right-of-way. These nectar-rich flowers were magnets for all kinds of insects (other than beetles!), including several species of butterflies. A dozen or so each of large showy eastern tiger swallowtails and monarch butterflies flitted from blossom to blossom, occasionally unfurling their probosces to imbibe the flower’s sweet offerings.
I decided to head into the adjacent woods by following a fire line that snaked along the edge of a recent prescribed burn. I scanned the lush wall of vegetation that delimited the surrounding woods from the burn in hopes of finding multi-legged creatures. Nearly half an hour elapsed and all I had to show for my photographic efforts was a young Carolina mantid (Stagmomantis carolina) and a black-and-yellow garden spider (Argiope aurantia).
I saw a flash of shiny black wings among the foliage. My first thought was that it might be a mourning scorpionfly, but then it became clear that it was a female robber fly (family Asilidae) dining on a small wasp. I am no robber fly expert, but this particular fly reminded me of the genus Laphria, some of which are bee or wasp mimics.
Just as I was about to take a photograph, she was gone. Fortunately, I saw her land on a nearby leaf and she was still very much in possession of her lifeless prey. I leaned in to take the shot and, with the burst of my flash, she took to the air again. I watched intently as the shiny black fly flitted along the wood’s edge and landed on another leaf. Again, I slowly inched my camera toward her and watched her black shiny body fill up the frame of my viewfinder. And again, the flash of my camera caused her to fly away and into the burn area. I tracked her through several more landings on the low growth before she landed on a log. I took my third and last shot and she was gone. During the pursuit, a slightly smaller individual of the same species, possibly a male, also crossed my path.
I slowly walked all the way around the edge of the burn and back to the car, but saw no more robber flies. I told Paul that I had photographed what I thought to be a Laphria, but he said that the dark wings didn’t really fit any Virginia species in that genus. Paul would certainly know since he had recently published the first annotated checklist of the 115 species robber flies known to occur in Virginia (Bedell, 2010). I promised to post my best photo of the fly in question on my Facebook page as soon as I returned home.
Once posted, Paul suggested that it might be the very rare Orthogonis stygia, a species not yet known to occur in Virginia. I sent Paul all three of my images and he forwarded them to Eric Fisher for confirmation. Eric, a dipterist and asilid expert (and fellow alumni of Cal State Long Beach) quickly confirmed Paul’s identification and another new state record for Virginia.
Stanley Bromley (1931) first described this pompilid wasp mimic from three specimens collected in June; two of the specimens were from North Carolina and Mississippi, while the origin of the third specimen was unknown to him. Another specimen was later recorded from Florida (Bromley, 1950). Since then, specimens of this exceptionally rare species have been found in Alabama, Arkansas, Florida, Mississippi, Oklahoma, and Texas (Taber & Fleenor, 2003; Barnes et al., 2007).
Paul and I returned to the site only two days after I snapped my photos and searched several hours for Orthogonis. Although our efforts were in vain, we have not given up! Stay tuned for further developments
References
Barnes, J. K., N. Lavers, and H. Raney. 2007. Robber flies (Diptera: Asilidae) of Arkansas, U.S.A.: Notes and a checklist. Entomological News 118: 241-258.
Bedell, P. 2010. A preliminary list of the robber flies (Diptera: Asilidae) of Virginia. Banisteria 36: 3-19.
Bromley, S.W. 1931. New asilidae with a revised key to the genus Stenopogon Loew: (Diptera). Annals of the Entomological Society of America 24: 427-435.
Bromley, S.W. 1950. Florida Asilidae (Diptera) with description of one new species. Annals of the Entomological Society of America 43: 227-239.
Taber, S.W., and S.B. Fleenor. 2003. Range extension, habitat, and review of the rare robber fly Orthogonis stygia (Bromley). Southwestern Entomologist 29: 85-87.
For more information on robber flies visit:
Asilidae (Robber Flies) Page. A Page by Roy Beckemeyer <http://www.windsofkansas.com/Basilidae/asilid.html
Family Asilidae – Robber Flies <http://bugguide.net/node/view/151/bgpage>
Giff Beaton’s Robber Flies (Asilidae) of Georgia and the Southeast http://www.giffbeaton.com/Robber%20Flies.htm>
Robber Flies <http://hr-rna.com/RNA/Robber%20main%20page.htm>
Robber Flies (Asilidae) <http://www.geller-grimm.de/asilidae.htm>
The Robber Flies of Crowley’s Ridge, Arkansas. An Illustrated Guide by Norman Lavers http://normanlavers.net/>
September 24, 2011 at 11:00 AM
Hey Art! I have been following your stuff for some time and it is very inspirational. Very nice post! Stagmomantis carolina is an awesome spp of mantid. I have a post including them also on my blog… http://theinsectblog.blogspot.com/
Mind checkin’ it out? I’d really appreciate that.
September 24, 2011 at 11:07 AM
Thanks for your kind note Ryan! I like your blog, too, and have become a subscriber. Keep up the good work!
January 6, 2012 at 4:17 PM
Hi Art,
Each week I really enjoy listening to the ‘What’s bugging you’ on public radio. I think part of the reason that I enjoy it so much is that my grandfather was an entomologist and we had great fun together catching, photographing and talking bugs. Well, he did most of the talking actually.
Anyway, great blog, thanks!
steve
January 6, 2012 at 4:34 PM
Thanks Steve! What was your grandfather’s name and where did he work as an entomologist?
January 6, 2012 at 7:03 PM
Walter Weber – he went to and worked at Purdue and Dupont, he may have worked for other organizations but I’m not sure. He wrote some books too, ‘Diseases Transmitted by Rats and Mice’ and ‘Fleas, Ticks & Cockroaches Disease Transmitters’. By chance did you know of him? His basement was full of books and slides of insects. One of his ‘hobbies’ was to extract hornets nests from trees/buildings, put the nest in a mesh cage, then tally the hornets. Great memories!
steve
January 7, 2012 at 7:23 AM
I don’t know of him or his work, but it sounds like he was a very interesting fellow! Counting hornets in a nest is real dedication!!
January 8, 2012 at 6:05 PM
Is this becoming a significant trend, do you think? Warmer-environment species moving into new areas?
January 8, 2012 at 6:59 PM
Certainly. But the ranges of most insects, especially those of little or no economic importance such as this robber fly, are imperfectly known. As a result, it is almost impossible to say whether or not their populations are expanding or shrinking.
What’s Bugging You? is on 88.9 FM WCVE Richmond Public Radio http://www.ideastations.org/radio/archive/people/dr-art-evans
Join me on Facebook to find out about upcoming lectures, books, and other insect events
February 22, 2012 at 12:08 PM
A great collection and blog of insects. Thanks for sharing
February 24, 2012 at 8:48 AM
Thanks Jason!
September 5, 2012 at 12:06 AM
You sure have some great insects to photograph down your way! I’m a little envious!
Cheers,
EC
http://www.macrocritters.wordpress.com
October 22, 2012 at 7:21 AM
Thanks! I enjoyed your web site, too!
August 3, 2015 at 12:05 AM
Dr. Evans,
This blog is so interesting! I have a few photographs of an insect I believe to be in the family Alydidae of Broad-headed bugs, but I haven’t been able to identify it on several websites. Could I email them to you for some help?
Thanks!
RG
October 10, 2015 at 5:05 PM
arthurevans”at”verizon.net
September 24, 2015 at 5:37 PM
Hello Art
I’ve been watching your blogs for sometime now.“IN SEARCH OF A HOLY GRAIL” very nice. Keep it up. Best Regards
December 1, 2015 at 6:18 PM
Dr. Evans: last spring I was potting some annuals at my house when I saw what must have been a species of worm. It was unlike anything I had ever seen before. It was white, about the thickness of a piece of kite string and 5″ long. It was on the side of a corrugated box with its “head” swaying back and forth. I have a small clip of cell phone video. Is there a way I can forward that to the station for your review?
Thanks, Will
July 31, 2021 at 11:08 AM
Really appreciate the work you do, Art, We had a lady have an ID request yesterday on All Bugs Go To Kevin group in Oregon, and your photo of Buprestis viridisuturalis really helped me out, as no one could narrow it down (you of all people know how diverse Buprestidae are) anyways , after 500 plus pages in bugguide and iNaturalist, I finally found your photo. Thanks again for your dedication!
July 31, 2021 at 2:10 PM
Thanks for your kind note, Ash! Glad to be of assistance! By the way, that photo of B. viridisuturalis appears on p. 224 of my next book, Beetles of Western North America, that will be available in just a few weeks.