10 July 2016

Cobras on the Huron

Cobra Clubtails (Gomphus vastus) had not been vouchered for Washtenaw County, Michigan.  Given this county is one of the most surveyed in the state, I found this to be curious and made it a yearly quest after we moved here a few years ago.

This species has been observed and photographed several times over the recent years, but I don't know if they are more common now than in decades past.  Why wouldn't have any of the entomologists have collected a voucher in the past decades, if they were present?  (Of course, in my experience this is one of the more difficult clubtails to capture with a net)

Delhi Metropark appears to have a good population and easy access to both river and upland habitat.  Since this clubtail flies primarily in June, the weather in Michigan can be quite uncooperative.

The Huron River at Delhi Metropark
Some years the water is quite high, making access less than optimal.  Other years, it's rainy or cold, limiting the occurrence of the individuals.  Then there's the human influence: the metroparks show a lack of understanding regarding stewardship of natural areas.  The focus is on human recreation, even though their properties contain some of the best, and sometimes the only, natural habitat in regions of metro Detroit.  This year on June 24th, I found all of the upland areas (including non-turf grass) to be mowed.  Essentially nothing was left, except the edges with the woody, non-native invasives. Much of these mowed areas contained many native plants used by a variety of fauna, and are great perching and hunting areas for the adult dragonflies.  Maybe this helped me find an adult Cobra Clubtail?  As soon as I made it to an area between buckthorns (Rhamnus sp.),  an adult landed with its meal.  This female Cobra Clubtail was the only individual found on June 24th:

female Cobra Clubtail (G. vastus)

female Cobra Clubtail (G. vastus) subgenital plates

I also had time to visit Dexter-Huron Metropark which is a few miles upstream of Delhi.  The Huron River water level was low and allowed for easy wading.  A couple Cobra Clubtails were patrolling the river along with a couple Rusty Snaketails (Ophiogomphus rupensulensis).

The Huron River at Dexter-Huron Metropark

It was nice to find another location with the clubtails, but an interesting sight was this water snake with its meal (I assume it's a bullhead):

Northern Water Snake (Nerodia sipedon)

On June 25th, we returned to Dexter-Huron Metropark.  We found several species patrolling the river including: a couple Rusty Snaketails, two Comet Darners, multiple Swift River Cruisers, ...

female Rusty Snaketail (O. rupinsulensis)

female Comet Darner (Anax longipes)
male Swift River Cruiser (Macromia illinoiensis)

...and the target species of the day:

male Cobra Clubtail (G. vastus)

abdomen of male Cobra Clubtail (G. vastus)

It's difficult to know why this clubtail species wasn't vouchered in the past decades for Washtenaw County, given that other species utilizing the same river habitats were present.  At least we know the water quality and river structure allows this species' population to exist at this time.

09 April 2016

Latest Paper on Great Spreadwing in Michigan

The latest issue (Vol 28, Issue 1) of Argia includes our paper on the Great Spreadwing in Michigan.  Click here for a link to the paper. 

male A. grandis

Mark O'Brien along County Farm Drain

24 January 2016

New Macromia Species for Michigan

The latest edition of the Great Lake Entomologist includes a note of a new species for Michigan. Allegheny River Cruiser (Macromia alleghaniensis) was found at the Three Rivers SGA

male Allegheny River Cruiser at Wood Creek, Three Rivers SGA, Cass County, MI

12 July 2015

Sharonville SGA in early June

During the first week of June (3 and 6)  I checked a few locations of Sharonville SGA for new county records in Jackson County or additional ranges for species in Washtenaw County.

The hills and fields east of Prospect Hill Road and north of Sharon Valley Road in Washtenaw County provide many great upland areas to search for odes.

There were many female Spatterdock Darners (R. mutata) working the area and roadway, which is the county line.

face of a Spatterdock Darner (R. mutata)

female Spatterdock Darner (R. mutata)

Another open space area in Jackson County is located south of Fishville Road near where it turns north.  There are woodland edges, open fields, and nearby lakes.

Chalk-fronted Corporals (L. julia) were numerous and a few Frosted Whitefaces (L. frigida) were amongst the crowd.

Chalk-fronted Corporal (L. julia)

male Frosted Whiteface (L. frigida)

female abdomen of Frosted Whiteface (L. frigida)

Surprisingly, only one Four-spotted Skimmer (L. quadrimaculata) was found.

female Four-spotted Skimmer (L. quadrimaculata)

While searching through the shrubbery, I flushed a Lilypad Clubtail (A. furcifer) and hoped it wasn't the only individual in the area.  A bit searching turned up an additional male and female.

male Lilypad Clubtail (A. furcifer)
lateral view of claspers - male Lilypad Clubtail (A. furcifer)

dorsal view of cerci - male Lilypad Clubtail (A. furcifer)
female Lilypad Clubtail (A. furcifer)

dorsal view of abdomen - female Lilypad Clubtail (A. furcifer)

Another easily accessible area is north of Fishville Road and SW of Tamarack Lake.  There are clearings in the forest and adjacent to bog/wetlands which provide great perching and hunting areas for dragonflies.

A nice find was this Dusky Clubtail (G. spicatus):

male Dusky Clubtail (G. spicatus)

cerci of male Dusky Clubtail (G. spicatus)

Then a Swamp Darner flew by while working the edges of the woods and perched within net reach on a tree.  These are big darners and fairly easy to identify on the wing (even at a distance).

male Swamp Darner (E. heros)

Before departing I decided to check out the short dock at Tamarack Lake.  Soon after arriving a Cyrano Darner (N. pentacantha) flew by while working the edge of the lake.  2015 seems to be a good year for this species since I've found them at a few locations.  More individuals than I had seen in the the previous several years combined.

male Cyrano Darner (N. pentacantha)

I'll have to check these upland areas throughout the flight season.  The variety of habitats are sure to host many other species.

02 July 2015

June is Gomphid Time

This year I wanted to confirm flying adults of a couple species of clubtails for Washtenaw County.  Cobra Clubtail (Gomphus vastus) and Riverine Clubtail (Stylurus amnicola) adults had been photographed by others in past years.

I started searching May 23rd at Hudson Mills Metropark along the Huron River.  Several exuviae and one emerging Rusty Snaketail (Ophiogomphus rupinsulensis) were found.

emerging Rusty Snaketail (O. rupinsulensis)

One of the collected exuviae appears to be Cobra Clubtail (G. vastus) and will be checked by another person or two.

Here is a closeup of the exuvia of the emerging snaketail.

Rusty Snaketail (O. rupinsulensis) exuvia
On May 28th I checked Delhi Metropark and found more exuviae.  Again, Rusty Snaketails and an apparent Cobra Clubtail (which needs confirmation) were collected.  Teneral adults were observed flying up to the trees along the Huron River.  The days and nights following this visit were quite cool/cold and I wonder if the teneral individuals survived since I didn't find good numbers of clubtails in the following week.

Also present were a few Rapids Clubtails (G. quadricolor) and a couple Cyrano Darners (Nasiaeschna pentacantha). 

male Rapids Clubtail (G. quadricolor)
male Cyrano Darner (N. pentacantha)

On June 3rd Sharon Mills County Park had a few species including Unicorn Clubtail (Arigomphus villosipes).

female Unicorn Clubtail (A. villosipes)
On June 11th, I visited Sharon Mills and only found Unicorn Clubtails once again.  I headed downstream to the Raisin River crossing at Sharon Valley Road.  There were Rusty Snaketails (Ophiogomphus rupinsulensis), Swift River Cruisers (Macromia illinoiensis), and a few male Green-faced Clubtails (Gomphus viridifrons).

male Green-faced Clubtail (G. viridifrons)
dorsal view of a male Green-faced Clubtail's abdomen

On June 13th, I returned to Delhi Metropark and finally had success with one of my targets.  Flying adult Riverine Clubtails (S. amnicola) were out and I saw at least two males.

male Riverine Clubtail (S. amnicola)

I may have glimpsed a Cobra Clubtail (G. vastus) up in the trees, but it didn't allow a proper view for identification.  Also present were approximately ten female Rusty Snaketails (O. rupinsulensis) perching in the vegetation away from the Huron River. 

female Rusty Snaketail (O. rupinsulensis)

I returned to Delhi Metropark on June 18th and saw one Cobra Clubtail (G. vastus) but it was skittish and too far away to be photographed.  There were also a couple young female Riverine Clubtails (S. amnicola).

female Riverine Clubtail (S. amnicola)

The Cobra Clubtail (G. vastus) eluded me throughout June, but I still have some time in July, or there's always next year.