21 July 2019

The mystery of meadowhawks, redux

I'm a RuWhiChee! Read more here.

In 2010, we posted about the difficulties presented in identifying many Sympetrums, especially in eastern North America. With the increasing popularity of dragonfly ID and photography, and posting same on social media and citizen science websites, we have updated our post with some new data and references. I'll repeat the bottom line here, and you can read more at the original posting:

Over most of eastern North America, the most common meadowhawk species (Ruby, White-faced, Cherry-faced, and Jane's) should not or cannot be identified to species from a photograph -- especially when immature. Often, they cannot even be identified to species in the hand because the structural characteristics of their genitalia are intermediate due to hybridization. In fact, DNA analysis has shown that some of these "species" may not be full species, or may still be undergoing speciation.

08 July 2019

Alleghany River Cruiser persists

In 2014, Stylurus snagged one of several river cruisers at a site in southwest Michigan that proved to be Macromia alleghaniensis, Alleghany River Cruiser. Not only was this new for Michigan, but a little research indicated that it was the most northerly record for this species, as most other records north of 40 degrees were unconfirmed for various reasons, as described in the paper we published (available here).

Download a PDF of this paper here.

Despite multiple visits to the site in the intervening years, we (mostly he!) could not confirm that this species had a sustaining population at this site. Visits took place in mid-June to mid-July, and while he saw river cruisers there in 2016, he was could not net one to see what it was.

We stopped once again on 23 June this year, and were in luck when we saw river cruisers cruising this creek, the same place where the voucher was collected.

The two photos above show each side of the creek at a road crossing.
Water was much higher than in previous years.
The task of netting one was made a little easier when I stood on the road as the patrolling Macromia approached to cross the road to the other side. I could act as a spotter, and the dragonfly would usually turn back if it saw me standing there. In this way, Stylurus was able to net multiple river cruisers, all of which turned out to be M. alleghaniensis. Although we only saw one or two at a time, each time one was netted, another showed up (we held on to them until we were satisfied all were Alleghany before releasing all but two vouchers). We think there were at least 7 patrolling, and likely more. It was satisfying to know that this appears to be a healthy, sustaining population -- especially in a year with so much rain in spring and early summer that the creek was still running high.

I'm just posing here.

Identification and taxonomy of Macromias can be tricky (for a pretty thorough introduction, see Donnelly and Tennessen 1994). As with many ode identifications, structure trumps color pattern. One reliable character is the length of the mesotibial keel, a little "flange" on the middle leg, illustrated in this photo by Michael Moore. Much shorter on Alleghany than on similar M. illinoiensis.

Since our original discovery, a few other states have added this species to their lists after closer examinations of specimens. Two such revelations have been published in Argia: Brown and Thomas (2016) and Patten and Smith-Patten (2016). Links to all these resources are below.

Brown, G., and Thomas, M. 2016. Discovery of the Allegheny River Cruiser (Macromia alleghaniensis) in Rhode Island and Connecticut. Argia 28(2):9.

Donnelly, T. W., and K. J. Tennessen. 1994. Macromia illinoiensis and georgina: a study of their variation and apparent subspecific relationship (Odonata: Corduliidae). Bulletin of American Odonatology 2(3):27-61

Patten, M. A., and B. A. Smith-Patten. 2016. The Allegheny River Cruiser (Macromia alleghaniensis) in Oklahoma. Argia 28(3):12-14.

02 February 2019

Latest Paper on Rediscovered Spiketail

We published a paper about refinding Tiger Spiketail (Cordulegaster erronea) in the Great Lakes Lakes Entomologist (50(1-2):1-5 · January 2017) a couple years ago. I thought it would be worthwhile to note this paper given similar habitats that may be occupied by Tiger Spiketail and Gray Petaltail (T. thoreyi) that we found at Fort Custer Training Center in Kalamazoo County, Michigan.

Title and Abstract.  Note: both Julie Craves and Mark O'Brien have retired from their positions posted

Individuals were initially found on July 3, 2016, and multiple individuals were found in June-July-2017.

female Tiger Spiketail posed along two-track
male Tiger Spiketail perched on sunlit branch
In 2017, I searched habitats near the two-track in order to find potential breeding site(s).   The most promising location was south of the area with a seep flowing from the hillside and forming a rivulet.  This traveled a couple hundred meters before ending in a marshy / fen area.  Further downstream is a large fen area.

close-up of seep likely to be a breeding site
flow into the swampy area

12 January 2019

Looking for a Gray Ghost

Gray Petaltail (Tachopteryx thoreyi) is listed as state threatened in Michigan, as noted on the MNFI website.  Prior to living in Michigan, I'd only observed the species once.  It was an individual that flew by and landed on a bridge over a stream in the knobs of Kentucky.

Over the past several years, we've been searching to confirm this species' presence in some historic locations and other spots suggested by locals.  It appears that the petaltail only inhabits the SW area of Michigan, given the records and searches throughout the southern tier of counties. Prime flight season may be mid-June through mid-July.  For me, the 3rd weekend of June is prime time.

In recent years, I've visited Berrien, Kalamazoo, Cass, and St. Joseph counties.
Some locations included:

- Grand Mere State Park:  I heard petaltails were present in the hillsides near Stevensville in the years prior to the construction of I-94 was constructed. The wetlands in the SE area of the state park were ditched decades ago, but may have seeps which provide habitat.  During a couple visits, no individuals were observed, but habitat is interesting.

ditch with seeps in woods

- Warren Woods State Park:  There is a 1919 voucher from this location.  In 2014, one was observed on June 17, 2014.

male Gray Petaltail on railing of bridge

- Three Rivers SGA: This state land has habitat in Cass and St. Joseph counties.  There is a 1989 voucher from Wood Creek in Cass County.  Multiple individuals were observed around June 18, 2016, in the same area.  Some were hunting over Wood Creek, while others were most easily found perched on conifer trunks in dappled sunlight.  Scanning trees with binoculars from the creek seemed to be the best method, but a couple times I had a patrolling/hunting individual fly past along Wood Creek.

female Gray Petaltail perched on snag along Norton Road, Cass County

female Gray Petaltail perched on conifer along Wood Creek, Cass County

Additionally, the habitat along Mill Creek, west of Preston Road in St. Joseph County looks promising.  Many seeps and fen habitat is present, but is somewhat difficult to access:

potential petaltail perching sites above hillside seeps

- Dr. T. K. Lawless County Park: I was told this park may have appropriate habitat and when visiting out of season, there were some interesting hillsides that seemed to have seeps along trail #4.

 - Fort Custer Training Center:  I was informed that that petaltails had been observed in an area of hilly, forested area with seeps.  During multiple visits over a couple of years, none were observed. However, other interesting dragonflies were found.  It is possible that petaltails are present, but we had no luck.

Two-track adjacent to hillside seeps

Watkins Lake State Park: Additional searching of prairie fen areas and nearby hillsides may be worth further searching. This may be a bit of a stretch since petaltails have not been found at Ives Road Fen through the years.

Norvell-Manchester Drain, bordered by prairie fen

Gray Petaltails are tough to find in Michigan, even when in the proper habitat. For example, it took six visits before I saw the first petaltail at Three Rivers State Game Area.  As time allows in future years, I hope to revisit locations that looked appropriate but didn't turn up any individuals.