30 May 2010

Cordulegaster obliqua Revisited

For over a year I've been itching to get photos of an adult Arrowhead Spiketail (Cordulegaster obliqua) in the hand. It all started when I found a population in Wayne County, Michigan, in May of 2009 at Lower Huron Metropark.

The end of May-2010 had many warm, sunny days and I knew this species would be flying.

On May 29th, I began my search around 9:30am at the end of a little holler and found a female perched in dappled morning light. Unfortunately, the lighting didn't permit a reasonable photo with my point-and-shoot camera and the perch was in a tough location to net her (brambles and thick branches). I called Nannothemis encouraging her to come with her good camera, and, hopefully a great shot. Of course, the bugger didn't cooperate.

While searching the rivulet, a patrolling male was observed. It is amazing how these odes "appear" and "disappear" directly in front of you due to the dappled light and their light and dark dorsal pattern. The lighting was poor once again for a photo and obtaining one in flight is near impossible for me.

Every time I walk this small waterway, I search for exuviae. Surprise, I found three!
It's amazing how well the exuviae blend in with the trunks and if one isn't looking from the proper angle, they are nearly invisible.

The photo below shows one exuvia on a tree trunk and a second exuvia is present on the tree trunk in the background. The rivulet shows in the "distance":

This is the second exuvia of a female:

How did I know it was a female? The underside shows where the ovipositor develops on abdominal segment 9. Here is a ventral view:

Here is a close-up of the ovipositor (the small, dark triangle):

...and, finally, the third exuvia that blended in very well with the flaky bark:

This third exuvia was found on the trunk of the tree in the left of this image:

On May 30th, I stopped by hoping for better opportunities around 10am to observe this large dragonfly and was immediately rewarded with a male perched at the "magic spot".

However, I wasn't pleased with the lighting or the image due to my attempt at digiscoping this individual through my binoculars. I continued my search up the holler and came up empty so I returned to the "magic spot" and found two males. I finally had my chance for photos in the hand:

Head shot showing how the eyes are teardrop-shaped and nearly touch in the center:

Close-up of the thorax:

Close-up of the claspers:

Dorsal view of the abdomen, showing its namesake:

Hasta luego:

Late May odes for Wayne County

For late May-2010, here is another combination of several outings in one post.

May 29 at Lower Huron Metropark
: I was anxious to look for C. obliqua and the results will be noted in a future post.

Midland Clubtails (Gomphus fraternus) were numerous such as this obelisking female captured by Nannothemis:

May 29 at UM-Dearborn: Nannothemis wanted to check Fairlane Lake and the Rose Garden pond.

Two male Unicorn Clubtails (Arigomphus villosipes) shared perches on the south end of Fairlane Lake. Here is one digiscoped through my binoculars:

Dot-tailed Whitefaces (Leucorrhinia intacta) flitted about the Rose Garden pond and here is a perched male:

The best find were the Marsh Bluets (Enallagma ebrium). This is a new location in the county for us and here is one of the males:

May 30 at Crosswinds Marsh: I keep looking for Springtime Darners (B. janata) in Wayne County and thought I'd poke around this mitigated wetland. I found hundreds of Sedge Sprites (Nehalennia irene) and the big surprise was a Four-spotted Skimmer (Libellula quadrimaculata), but unfortunately no photo.

Twelve-spotted Skimmer (Libellula pulchella), three times too many spots, but this female was the first of the season of this species for me:

May 29 at Willow Metropark: I checked another location to continue my search for Springtime Darners (B. janata). No luck, but I did find another location for clubtails.

Midland Clubtail (Gomphus fraternus), the mosquitoes were bad, but here's a female that was patrolling the edge of this field:

May 30 at the Humbug Marsh Unit of the Detroit River International Wildlife Refuge: Nannothemis and I hope to visit every couple weeks to survey for odes since the Chrysler property has a new pond/lake/sea.

Immediately, we spotted a Unicorn Clubtail (Arigomphus villosipes) utilized the edge of the water. Here's one of the males with the Trenton Power Plant stacks in the background:

Spot-winged Glider (Pantala hymenaea), we found two, one patrolling a shallow pool and this female hunting over the eastern fields:

While walking the eastern fields, we saw multiple Swamp Darners (Epiaeschna heros) hunting the edges of the dogwoods and cottonwoods. Here is one of the females of this large species:

... and there were Common Green-darners (Anax junius) making more:

May 31 at Crosswinds Marsh: I returned to look for the Four-spotted Skimmer (Libellula quadrimaculata), but I had another nice surprise with two Painted Skimmers (Libellula semifasciata):

... more interesting odes in posts to come:

29 May 2010

Mid-May dragonflies in Southeast Michigan

I've been lax putting up current posts for this year's dragon hunting. Thus, I'll catch up by combining a few outings in one post.

May 15 at Lower Huron Metropark: I wanted to look for possible early Arrowhead Spiketails (Cordulegaster obliqua), but no luck for this species. However, I did find some other early odes for the season.

teneral male Ashy Clubtail (Gomphus lividus):

One of a few male baskettails (Epitheca sp.), this individual was closer to E. costalis than E. cynosura:

female Common Whitetail (Libellula lydia):

May 16 at UM-Dearborn
: While doing a bird survey, several teneral Dot-tailed Whitefaces (Leucorrhinia intacta) were found along Jensen's Meadow.

May 23 at Willow Metropark: I thought Washago Pond may be a good area to search for Springtime Darner (Basiaeschna janata), but was wrong. However, I did find a nice variety of odes.

One of two male Familiar Bluets (Enallagma civile):

A coupled pair of Orange Bluets (Enallagma signatum):

An emerging dragonfly, possibly a Common Whitetail (Plathemis lydia):

A male Dot-tailed Whiteface (Leucorrhinia intacta) with wings that didn't unfold properly during eclosure:

One of six Black Saddlebags (Tramea lacerata):

Next up...late May...

Spring has Sprung!

During a lunch break of a conference I was attending on May 14th at the North Campus of UM - Ann Arbor, I took a walk around the wooded areas near the Huron River.

Much to my surprise a darner flew down the trail towards me, banked and somewhat crash-landed next to me. Immediately I recognized this as a Springtime Darner (Basiaeschna janata) and I was able to grab it by hand. (This male may have been focused on prey it had captured.)

The top of the head:

The face:

Another lateral view:

This is a species I've been trying to find in Wayne County for years and I've only had a couple of unsatisfactory looks from a distance. Here, I had an hour in Washtenaw County and find one without even searching. Sometimes one is lucky and sometimes not.

03 May 2010

We don't know it all

People are often surprised at how many new county (and even state) records Stylurus and I have been able to find in such a populated and developed county such as Wayne in Michigan. People, there are still species left to discover. Big, conspicuous ones. In the United States. Here are some accounts of a new spiketail from east Texas by the discoverer, Greg Lasley, and Martin Reid.

Odes are on the wing here in southeast Michigan, so expect posts to resume here as our field season begins.