The Backstory: A Southern Fortnight
For the first two weeks during May 2015, Southern Spreadwing damselflies (Lestes australis) were observed at a vernal pool and nearby drainage ditch in the forest at Huntley Meadows Park. I spotted approximately six males and several females during the fortnight. Their sudden disappearance seemed to coincide with a population explosion of Eastern Pondhawk dragonflies (Erythemis simplicicollis) in mid-May. Eastern Pondhawks, especially females, are voracious predators with a penchant for preying upon damselflies.
During late-May 2014, I photographed a spreadwing damselfly near a vernal pool at Huntley Meadows Park. When I revisited the photos months later, I realized the damselfly was a species I’d never seen.
Ed Lam, author and illustrator of Damselflies of the Northeast, identified the specimen as either a Southern Spreadwing damselfly (Lestes australis) or Sweetflag Spreadwing damselfly (Lestes forcipatus). According to Ed, this individual “… is a male. Male Southern and Sweetflag cannot be separated in the field.”
That was November 2014. This is May 2015 and they’re back! Although male Southern Spreadwing and Sweetflag Spreadwing damselflies are virtually indistinguishable unless examined in-hand under magnification, I was fortunate to photograph a mating pair. With Ed’s help, we were able to reverse-engineer a positive identification based upon a single key field marker for the female member of the pair: Its ovipositor is too small to be a female Sweetflag, so by the process of elimination these damselflies must be Southern Spreadwing — a new species for both Huntley Meadows Park (HMP) and Fairfax County, Virginia!
The wheel position is sometimes referred to as “in heart” when damselflies mate.
The final photo in the time-series shows the male member of the mating pair immediately after the male and female separated.
The following photos show two slightly different views of another male spreadwing damselfly spotted at the same location as the mating pair. Although it’s possible these damselflies may be Sweetflag Spreadwing, they are probably Southern Spreadwing.
- Another new species of spreadwing damselfly…
- A Southern Fortnight, Part 1 – Year-long mystery solved!
- A Southern Fortnight, Part 2 – Damselfly terminal appendages (male)
- A Southern Fortnight, Part 3 – Southern Spreadwing damselfly (male)
- A Southern Fortnight, Part 4 – Southern Spreadwing damselfly (female)
- A Southern Fortnight, Part 5 – Southern Spreadwing damselflies (mating pairs, in tandem)
- A Southern Fortnight, Part 6 – Damselfly reproductive anatomy
- A Southern Fortnight, Part 7 – “Arty”
Copyright © 2015 Walter Sanford. All rights reserved.
Tags: adult female, adult male, Eastern Pondhawk dragonfly, Erythemis simplicicollis, Family Lestidae (Spreadwings), Huntley Meadows Park, in heart, in wheel, Lestes australis, mating pair, ovipositor, predator, prey, Southern Spreadwing damselfly, vernal pool, wildlife photography