04 July 2014

Ophio Odyssey - day 1, stop 1

As noted in a previous post, I was searching for evidence of two rare snaketails (Ophiogomphus) in the western UP (upper peninsula) of Michigan.  Dave Cuthrell from MNFI gave me information of previous locations in and around Iron County of Pygmy Snaketail (O. howei) and Extra-striped Snaketail (O. anomalus).

1st stop = Brule River Bonanza
On Wednesday, 6/11/14, I took off from Houghton Lake in the rain, but that was OK since I had a 6-hour drive ahead of me to get to Iron County in the western UP.  The radar showed that I should be driving out of the rain during the morning so I had hoped for good weather at midday when I arrived.

Highway 2 was my route for most of the drive and is quite scenic along the north end of Lake Michigan.  I had no time to stop since the Ophiogomphus (ii) were waiting for me.  This highway dips down into Wisconsin before turning north back into Michigan.  In this area the Brule River is the border between the two states. This bridge crossing has a great pulloff and access to the water.
 The river here had a moderate flow and was generally knee-deep with a gravelly substrate, a few larger rocks under the bridge, and some silty areas near the bridge abutments or bends in the river.  There was also a small, cold stream entering on the downriver side of the bridge.  This stream was only an inch or two deep and about a foot wide.

Upon exiting my car, I was amazed at the swarm of baskettails (Epitheca sp.) over the road.  Quickly netting one confirmed a Beaverpond Baskettail (E. canis) and it appeared that most were this species with the distinctive cerci.

Knowing that my target species of Ophiogomphus would be difficult to find or catch over the river, I initially checked under the bridge for exuviae (or larval skins).  Jackpot!  I hadn’t studied the features or shapes of the intended species, so I collected all that I could find knowing I could potentially add a species to the county list or expand the known distribution of others.  I had a zip-lock bag that I clipped to my pack and filled it up with 30 exuviae.  As of today, I’ve made my attempt for species IDs of these exuviae and Ethan Bright has offered to examine the undetermined ones. (two dozen Ophiogomphus rupinsulensis or carolus ?,  one Ophiogomphus anomalus, Ophiogomphus sp.?, one Macromia illinoiensis,  and one Calopteryx aequabilis).  The Extra-striped Snaketail (O. anomalus) confirms a new location for the species!

Here's an example of an Ophiogomphus exuvia on the bridge:

It was a calm, sunny afternoon and there were many adults flying over the river including: 
River Jewelwing (Calopteryx aequabilis), 
American Rubyspot (Haeterina americana)
Springtime Darner (Basiaeschna janata), 
Swift River Cruiser (Macromia illinoiensis), 
Ashy Clubtail (Gomphus lividus), 
Green-faced Clubtail (G. viridifrons), 
Beaverpond Baskettails (E. canis), 
Four-spotted Skimmers (Libellula quadrimaculata), 
Rusty Snaketail (O. rupinsulensis), 
and several Riffle Snaketails (O. carolus). 
Here's a male Riffle Snaketail:

Success with finding one of the two target species (O. anomalus), thanks to the larval skin left on the bridge or nearby vegetation.
Next stop: the Paint River

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