Bombyliidae: Geron sp.

You know I have a bit of an obsession with bee flies, even ones I haven't seen myself. Here's a cutie I found today. The odonata update is below.



















This tiny, hump-backed little bee fly is probably from the genus Geron.

A Spreadwing Update

Yesterday, I spent some time at the University of Michigan Museum of Zoology in the odonata range with the accomodating and helpful Mark O'Brien, researching some of the species that have been recorded in Wayne Co. that I personally have not seen. The big news, I guess, is that Elegant Spreadwing, Lestes inaequalis, is now striken from the list. It's inclusion was based on a lone record, a female specimen taken several years ago. I took a look at it, and lo and behold, it was mislabeled (note, MFO: I could have said "misidentified"). Males are easy to ID, their inferior (lower) claspers are longer than the superior (top) ones. You can kind of see this in the photos here and here, but it's really obvious in the hand, even without magnification. Females ("Lestes without testes" Mark calls them), however, usually require a microscope and some experience. I've looked all over hell's half-acre in the county for this species, but so far no luck.

We also went over some literature records. Several are from prior to 1880 (Hagen's Bluet, Enallagma hageni; Canada Darner, Aeshna canadensis; Mottled Darner, A. clepsydra; and Williamson's Emerald, Somatochlora williamsoni), and others might be in error. Of the 90 species on the checklist, there are only 13 I haven't seen, and half of them are species that either haven't been seen for over 100 years or that I suspect are in error. Eventually, Mark and I became sidetracked into reading some of the correspondence given to the museum by E. B. Williamson (the MOS newsletter's namesake) from colleague Clarence Kennedy. I always find it interesting to get to know historical figures from a personal perspective rather than just seeing their published papers and the results of their field work. Let's just say that these two men were particularly intriguing; Mark promises to liven up our winter months summarizing some of these riveting letters in his blog.

Today I was hoping to find either Elegant Spreadwing or Common/Southern Spreadwing (Lestes disjunctus disjunctus and L. d. australis). There actually aren't that many L. d. disjunctus specimens from southern Michigan; I don't find them all that common. There are just a smattering of L. d. australis specimens from the state.

Now that I have a bike rack, I'm able to explore further afield at the metroparks. There is a 3-mile stretch between Lower Huron and Willow metroparks that, from an aerial view, looked to have a nice old wooded oxbow near the bike path, so that's where I headed. This was nearly all dried up, just squishy much and lots of wetland vegetation. It was loaded with Lestes, mostly Sweetflag Spreadwing, L. forcipatus. Wherever I find these, I find A LOT of them. The males look pretty much like Common Spreadwings. The easiest thing to do is catch a pair and take a look at the female. If her ovipositor is longer than her superior anal appendages, like this, then it's a pair of Sweetflags. I netted every nth pair that I couldn't get a good look at through binoculars, but could not come up with Common/Southern. There were a smattering of Slender Spreadwings, L. rectangularis, some Ruby Meadowhawks, Sympetrum rubicundulum, and the many of the ubiquitous Blue-fronted Dancers, Argia apicalis. Despite the lack of diversity, this looks like a great spot earlier in the season, and later on for patrolling Aeshnas. I'm headed to a different spot furthern downriver tomorrow.

Skimming Bluet

Getting tired of seeing me post damselfy photos? Well, for me, the bluets are like miniature shards of the deep blue July sky, skittering through the grass at my feet, and symbolic of the summer season I love so much.

Skimming Bluets (Enallagma geminatum) are very dainty, and usually seen dancing over glassy-surfaced ponds. This one paused nearby for me to admire.

Blue-ringed Dancer

The Blue-ringed Dancer (Argia sedula) is the least common of the blue dancers in our area. Although I noted them along the Rouge River some years ago, I did not encounter them again until yesterday, when I obtained the necessary first voucher specimen to put them officially on the Wayne County list. I think they are the most beautiful of Michigan's Argias; this photo hardly does them justice.

Great Blue Skimmer: New for Michigan

Great Blue Skimmer (Libellula vibrans) was first recorded in Michigan in 1995, described in a paper published (in Japanese) in the journal Aeschna by Tokihiro Nishida. He had one on 22 June 1995, and photographed a male 10 July 1995, at a small wooded wetland in Westland, Wayne Co. If he obtained a specimen, it is not in the University of Michigan odonata collection.

I think I've looked at this paper, with its tantalizing color photos of species in the county that I have yet to find, dozens of times. In 2004, I went to what I figured HAD to be the swamp Nishida described in Westland, an extremely built-up community. It could only be at Holliday Nature Preserve, a county park. Although I returned again and again, finding other species he noted there, there was no sign of L. vibrans. The swamp also appeared to be filling in with button bush and fallen trees, as seen below.

Accessible wooded ponds are hard to come by in this county. One other looked promising, but repeated visits in 2005 did not turn up this species. Perhaps Nishida's Great Blue Skimmers were just wanderers, and would not be found again without luck, and a year when conditions, perhaps drought in the southeast, brought L. vibrans north to Michigan.

I thought perhaps this might be the lucky year. The Northeast Odes listserv noted an influx of Great Blue Skimmers in New York state. Mark O'Brien reported sightings in Washtenaw Co. just last week. In fact, he told me he was going to go try to voucher one for the first official state record on Saturday. Alas, I was committed to do a survey at Humbug.

We finished our survey of Humbug yesterday (which did not turn up Comet Darner, Painted Skimmer, or any other interesting odonate) sooner than expected, so Stylurus and I decided to head up to Holliday NP. Within five minutes of arrival, I called excitedly over our two-way radios "It's here! I have a male over here!" Just like the books said, this Great Blue Skimmer kept returning to his perch in the dappled sunlight after looping out over the swamp. The very mucky, duckweed-covered-water-0f-indeterminate-depth swamp. Right in front of me. So close and so obstructed by branches I could not possibly get a good swing. I had promised myself if I finally found this thing I'd go in the water after it. Momentarily, I was standing in some very fragrant, warm-as-piss gunk. Stylurus arrived in time to see our bug quite well, before it flew out over the button bushes. We hunted as best we could to no avail.


This brought about a change in today's plans. After doing some other surveying, we arrived at Holliday at about 1:30 PM, wearing rubber boots in 90 degree weather. We went in separate directions, and searched unsuccessfully for half an hour. I sat on a moss and raccoon-crap covered stump, wondering how many dozen Blue Dashers I could stand watching in this reeking place. Suddenly, the radio beeped...Stylurus had two males staked out at the opposite side of the swamp!

One cannot race through this area. The water was opaque and filled with downed trees. I made it half way around and onto "land" before I stepped into a hole and collapsed in the putrid mud. I can't cut to the chase -- that was it -- but suffice to say we had a number of males in a much shallower (albeit no less stinky) spot. We were able to obtain some mediocre photos and a voucher for Michigan's first state record -- 10 years to the day that Nishida had one in the exact same place. Domo arigato, Nishida-san.

Nishida, T. 1999. The odonata collected in the United States of America, mainly in the State of Michigan. Aeshna 36:1-20.

Update:
Craves, J. A. 2006. First Michigan specimens of Libellula vibrans Fabricius (Odonata: Libellulidae). Great Lakes Entomologist 39: 91-93.