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.
An adult female Southern Spreadwing was spotted perching on vegetation alongside a drainage ditch in the forest. She was resting after laying eggs (oviposition) in tandem with an adult male Southern Spreadwing.
Slaty Skimmer (Libellula incesta) is a member of the Skimmer Family of dragonflies. Females lay eggs (oviposition) by skimming the water surface repeatedly, hence the family name “Skimmer“; two flanges beneath their eighth abdominal segment (S8) scoop water that is used to flick fertilized eggs toward shore, as illustrated in the following annotated image. Remember that all dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back.
10 JUN 2015 | Huntley Meadows Park | Slaty Skimmer (mature female)
The following movie shows the same female laying eggs in a large pool of water downstream from the central wetland area at Huntley Meadows Park on 10 June 2015.
Tech Tip: The preceding movie looks better viewed in full-screen mode.
Male and female Common Sandragons look similar, especially their coloration. Terminal appendages may be used to differentiate males from females.
Female dragonflies have a pair of cerci (superior appendages) that have little or no function. (See a full-size version of the following image, without annotation.)
Male dragonflies have three terminal appendages, collectively called “claspers,” that are used to grab and hold female dragonflies during mating: an upper pair of cerci (“superior appendages”) and a lower unpaired epiproct (“inferior appendage”).
Look closely at the full-size version of the following composite image contrasting the terminal appendages of a male and female Common Sanddragon dragonfly. One look at the individual with the distinctive large yellow cerci and you know which one is the male!
Composite image: male (background photo); female (inset photo).
On an overcast, rainy day I was pleasantly surprised to see several male Common Sanddragons and a single female. A few photos of the males are featured in this post; a photo of the female will be published in a follow-up post.
occiput: posteriormost area on top of head, behind vertex and ocelli. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Location 11671). Princeton University Press. Kindle Edition.
Look closely at the full-size version of the following annotated image. Notice there is a small “horn” located in the center of the Unicorn Clubtail’s occiput, hence the first part of its common name. Also notice the tip of its abdomen is slightly club-shaped — now you know the rest of the story.
Bar-winged Skimmers have dark reddish-brown eyes and a metallic black face; Great Blue Skimmers have blue eyes and a white face. Also notice the Bar-winged Skimmer has a small black bar along the “costa” (the leading edge of both the fore- and hind wings), located between the nodus and pterostigma — hence its common name, “Bar-winged Skimmer”; the Great Blue Skimmer does not.
Widow Skimmers display sexual dimorphism. Although mature males and females look different, immature males and females look similar. Terminal appendages may be used to differentiate immature males from females.
Female dragonflies have a pair of cerci (superior appendages) that have little or no function.
Male dragonflies have three terminal appendages, collectively called “claspers,” that are used to grab and hold female dragonflies during mating: an upper pair of cerci (“superior appendages”) and a lower unpaired epiproct (“inferior appendage”).
As a mature male, this specimen will develop white pruinescence on its body as well as white wing spots (located between the dark wing spots and pterostigmata). The white wing spots are faintly visible in some photos, such as the one shown below.
I’m especially fond of head-tilts in which the dragonfly seems to display some of its personality. Sometimes I tend to project my thoughts into the mind of the dragonflies I photograph. After following this guy from perch-to-perch, I’m guessing he was thinking, “Hey pal, please stop following me!”
Digital Dragonflies: presenting high-resolution digital scans of living dragonflies.
Genus Libellula | Libellula luctuosa | Widow Skimmer | male | top view
Genus Libellula | Libellula luctuosa | Widow Skimmer | male | side view
Genus Libellula | Libellula luctuosa | Widow Skimmer | female | top view
Genus Libellula | Libellula luctuosa | Widow Skimmer | female | side view
Editor’s Note: With no disrespect intended toward Kevin Munroe, whom I admire and respect, I feel compelled to point out an error on Kevin’s Widow Skimmer page. In the lower-right corner of page 2, an immature male is misidentified as a female. Believe me when I tell you Kevin’s expertise far exceeds mine, but hey, only someone like me with a fixation on odonate terminal appendages would have recognized the immature male’s claspers!
Slaty Skimmers display sexual dimorphism. Although mature males and females look different, immature males and females look similar. Terminal appendages may be used to differentiate immature males from females.
06 JUN 2015 | Huntley Meadows Park | Slaty Skimmer (female)
Female dragonflies have a pair of cerci (superior appendages) that have little or no function. (See a full-size version of the following image, without annotation.)
06 JUN 2015 | Huntley Meadows Park | Slaty Skimmer (female)
Look closely at the full-size version of the preceding annotated image. Female Slaty Skimmers have a pair of flanges beneath their eighth abdominal segment (S8) that are used to scoop water when laying eggs (oviposition), hence the family name “Skimmer.” Remember that all dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back.
Immature male Slaty Skimmers and immature/adult female Slaty Skimmers are nearly identical in appearance except for their terminal appendages. (See a full-size version of the following image, without annotation.)
Male dragonflies have three terminal appendages, collectively called “claspers,” that are used to grab and hold female dragonflies during mating: an upper pair of cerci (“superior appendages”) and a lower unpaired epiproct (“inferior appendage”). (See a full-size version of the following image, without annotation.)
06 JUN 2015 | Huntley Meadows Park | Slaty Skimmer (young male)
This individual is a young male, as indicated by the blue-black partial pruinescence covering his body. He has a slightly malformed wing that is more noticeable in the preceding side view and less noticeable in the following dorsal view.
06 JUN 2015 | Huntley Meadows Park | Slaty Skimmer (young male)
Black pruinescence that completely covers the body of following mature male Slaty Skimmer makes it look quite different from the immature male (shown above), other than its terminal appendages.
Look closely at the full-size version of the following annotated image. Female Great Blue Skimmers have a pair of flanges beneath their eighth abdominal segment (S8) that are used to scoop water when laying eggs (oviposition), hence the family name “Skimmer.” Remember that all dragonflies and damselflies have a 10-segmented abdomen, numbered from front to back.
Immature Great Blue Skimmer dragonflies and immature Slaty Skimmer dragonflies (Libellula incesta) — including both females and males — look very similar. In my opinion, the best field mark for differentiating the two species is femur coloration: Great Blue Skimmer femora are mostly tan; Slaty Skimmer femora are mostly black.
The following female Slaty Skimmer was spotted along the “Hike-Bike Trail” at Huntley Meadows Park. Contrast the difference in coloration of the Slaty Skimmer femurs (below) with the Great Blue Skimmer femurs (above).
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