25 May 2009

Early Gomphids and a life ode

I continued the search for the early darner by visiting Lower Huron Metropark. I am somewhat at a loss where to find the Springtime Darner (Basiaeschna janata) in Wayne County, but I'll continue searching this location as you'll read at the end of the post.

I started and ended at the Woods Creek Picnic Area. This is adjacent to the Huron River and has a small creek running through a wooded hollow that is great for clubtails (Gomphus sp.) this time of year. Immediately upon my arrival, I began kicking up recently emerged Ashy Clubtails (Gomphus lividus) along the two-track and on the adjacent vegetation.

Walking through the grass of the open areas, I kicked up a couple of recently emerged Midland Clubtails (Gomphus fraternus) which also happen to be a new early date for Michigan.
Here's a male:

And a female:
Soon after this I saw a life ode working the edge of the forest. Initially Dragonhunter came to mind, but I realized that it was too early for that species. The individual was large (50% larger than the clubtails I was examining) and black with bright yellow markings. The dragonfly was hunting along the bushes and small trees of the partly shaded opening. Then luck was on my side and it perched on a twig, hanging vertically from the tip.

Immediately, I recognized the following:
  • eyes touching at a point on top of the head = spiketail (Cordulegaster)
  • yellow arrowhead markings along the dorsal surface of the abdomen = Arrowhead (C. obliqua)
  • long ovipositor extending beyond the tip of the abdoment = female
No time for a photo as this female Arrowhead Spiketail (Cordulegaster obliqua) continued on her way.

I searched further and only had one more fleeting glimpse as she headed into the woods. While checking the immediate vicinity I found a small rivulet running from the hillside. This was a new water source that I wasn't familiar with and investigated further.

This looked like appropriate habitat from the little I knew of this genus. The water is one to a few inches deep and one to a few feet wide. The substrate was sandy with very silty and mucky areas.

This is one species I would have never expected to see in Wayne County (i.e., Detroit). There is one record of a male on June 14, 1931 in Detroit. In my mind, I had written C. obliqua off as an extirpated species for the county.

One never knows what can be found, even in the concrete jungle we call Detroit.

I returned the next day and had another brief glimpse of a hunting spiketail along the edge just before it began raining.

In future days, I'll check for flying adults, exuviae along the rivulet, or possibly nymphs in the water. Wish me luck!


Patrick B. said...

Very cool. I've seen that ode once here in NJ.

Darrin OBrien said...

thanks, Patrick

I just returned from the location and saw a flyby adult, then found a nymph and an emerging female. There will be another post coming in the next day.