27 July 2008

The Smallest Damselfly

On July 26, Nannothemis and I decided to check a couple locations of northwest Wayne County. There is rapid development in the area. Woodlots and wetlands are cleared, subdivisions are laid out, some houses are built then foreclosed upon. Or as it was in this location, office parks are defined, buildings are erected, then stand empty for years waiting for tenants. It's always depressing to check these areas, but we feel we have to make an effort to check them since some unique habitat was once present and may still be hanging on.

We visited a water retention basin in an office park that has held interesting dragonflies in recent years including Sedge Sprite (Nehalennia irene), Eastern Red Damselfly (Amphiagrion saucium), and Elfin Skimmer (Nannothemis bella). We've previously heard there is a small fen or bog nearby, but we've never been able to find it. One of the retention ponds holds water year-round since it is fed by a small trickle, but it has been filling in with vegetation over the years.

This weekend we were treated with a few Lyre-tipped Spreadwings (Lestes unguiculatus).

Here's the reason for its name:

A few Fragile Forktails (Ischnura posita) were present including some females with blue markings:

However, the best find was the couple dozen Citrine Forktails (Ischnura hastata). This population has persisted for a few years.
Here are a couple photos showing the bi-colored stigma.

Unfortunately, this pond may fill in with vegetation during the coming years, such as the encroaching phragmites. We typically find this smallest US damselfly species in shallow water with short sedges or grass.

Later in the afternoon, we stopped by the only known location in Michigan (a retail/restaurant complex) for the largest US damselfly. However, we didn't find any Great Spreadwings (Archilestes grandis) since it's still a bit early in the season for them.

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