Painted Skimmer (Libellula semifasciata)

Last night I was helping a friend sort and identify the odonate images on his HDD when I came across several striking photos of a female Painted Skimmer (Libellula semifasciata). The photo below was taken by Jason King on June 3rd, 2013, about 1.5 km west of Tweed, close to the location where we later discovered a colony of rare Juniper Hairstreaks.

I mistakenly thought the male dragonfly in the next image, taken in 2011, might be a Painted Skimmer, but it's actually an uncommon color variant of a Four-spotted Skimmer – Libellula quadrimaculata praenubila.

In addition to the differences in the wing and abdominal markings, the Painted Skimmer has yellow pterostigmata bordered in black. I would say the specimen in Jason's photo has some yellow in its pterostigmata with strong dark edging. however, they are definitely not completely black as in my Four-spotted Skimmer. Furthermore, according to accounts I've found on the 'net (for example, at Urban Dragon Hunters), L. semifasciata has fewer forewing crossveins than L. quadrimaculata. So barring further evidence to the contrary the dragonfly in Jason's photo is indeed a Painted Skimmer.

I had been forewarned as far back as June 2011 by a reliable authority to keep an eye out for this species in Hastings County, as it had been sighted regularly in Presqu'ile Provincial Park. And I've been recently informed that Libellula semifasciata has been recorded as far north as the Bruce Peninsula (2008 – 09) and Algonquin Park (2011).

It's now late July – two months since Jason encountered the Painted Skimmer. Assuming they emerge early in the season like their cousins, I doubt if they are still flying, and I'll have to wait until next year to acquire my own photos of this attractive dragonfly.

Off-Color Odonates

This female Libellula quadrimaculata (a.k.a. Four-spotted Skimmer) was encountered near the intersection of Alexander Street and the Eastern Ontario Trail. The dragonfly was foraging in a field of tall grasses, weeds and wildflowers. A small sand-and-rock bottomed creek and the Moira River are nearby. At first I mistook it for a Painted Skimmer as it flew by, but Libellula semifasciata would be a vagrant in this area.

The black patterning at the end of the abdomen and basal patches on the hindwings are correct for a Four-spotted Skimmer. However, not only are the spots at the nodes are larger and darker than the norm, but the wings are barred near their tips. I don't know what to make of this: is it a normal variation? A sport? Are hybrids between L. quarimaculata and L. semifasciata possible? At any rate, it's certainly different ...

The following day I saw another Four-spotted Skimmer with a dark wash near the nodes and wingtips at the same location, and also emailed a copy of the Four-spotted Skimmer photo to David Bree, who kindly responded: "... it is a dead ringer for a 4-spot. The amount of black at the tip of the abdomen is like a 4-spot and not a Painted as well. I don't think the node spots are bigger than normal. All these markers are much more distinct on young four-spots, they do fade with age ... Some pictures I've seen in field guides actually show this species with that same dusky wash though not quite as distinct as yours."

Another anomalous odonate: a female Dot-tailed Whiteface with a generous amount of amber at its bases of its wings. Now and again I've encountered Leucorrhinia intacta with a bit of color but this really caught my eye as the dragonfly hovered above the grass.

Changing with the Season

With the warmer weather of late spring and summer more species of dragonflies and damselflies are emerging and taking flight with each passing day. Depending on the species the larvae, called naiads, take from one to several years to mature. The flying adult most people are familiar with is the but final phase of the odonate's life; in a few weeks, before it dies, it must find a mate and start the cycle of life over again. The insects in the following images were photographed at the marsh bordering the Eastern Ontario Trail.

This small teneral dragonfly is a Whiteface. On the basis of habitat I'm tempted to say it's a Frosted Whiteface (Leucorrhinia frigida), but cannot rule out a Dot-tailed Whiteface (Leucorrhinia intacta). Both species are common in this area and I lack the experience to tell the tenerals apart.

Views of the exuviae; its length is 16 mm

Judging by the number of tenerals flying in the vegetation near our local marshes hordes of naiads are making the change every day, but actually catching them in the act of metamorphosing is difficult. The teneral insect's pale colors blend in with the low vegetation. This is a male Four-spotted Skimmer (Libellula quadrimaculata) and its exuviae.

As of late last year I had only Pauline Campbell's images to document a dragonfly undergoing the dramatic change from larva to adult. But having recently observed large numbers of tenerals along the shoreline of the marsh, this weekend seemed like a good time to go hunting for a naiad about to begin its final moult ... and it wasn't long before I got lucky.

The Four-spotted Skimmer (Libellula quadrimaculata) naiad in this next group of pictures was about fifteen feet from the water ... in fact, had already crossed the road and was heading for the marsh on the other side. Fortunately it didn't get stepped on by a hiker or run over by a four-wheeler.

Seeing opportunity knocking, I scooped the naiad into a baggie and took it to the garden where it could complete its metamorphosis in relative safety and I could take photos of the process in comfort. The dragonfly is extremely vulnerable to predators such as frogs and birds during this stage of its life. But turnabout is fair play; it's a good bet that this naiad has consumed a tadpole or two in its time ...

10:50 to 10:54 AM ... the naiad perching on a branch. The exoskeleton has been heaving and expanding as the adult dragonfly struggles to break out.

10:59 AM ... the outer integument has opened at the thorax; the eyes begin to show a few seconds later.

11:00 AM ... the eyes have emerged and more of the thorax is now free of the larval skin.

11:01 AM to 11:02 AM ... events are moving fast as the teneral adult begins to pull itself out.

11:05 AM ... a ventral view of the dragonfly hanging head down, with only the end of its abdomen remaining inside the exoskeleton.

11:14 AM to 11:16 AM ... having been upside down to this point in time, the insect now tries to heave itself into an upright position. Imagine trying to do situps while hanging head down! Eventually it succeeds and follows suit by pulling its abdomen free of the larval skin as well. With the abdomen visible we can see that this is a female.

11:22 AM to 11:23 AM ... the wings have been expanding as haemolymph (insect circulatory fluid) flows into them, and the abdomen continues to lengthen as well.

11:26 AM ... the teneral adult climbs up the branch, leaving the cast-off larval skin (exuviae) behind.

11:27 AM ... the wings and exoskeleton are still very soft – especially the wings, which are so limp that they blow like a flags in the breeze.

11:56 AM ... the dragonfly's body is beginning to assume a more adult profile. Although the wings are still folded together over its back, they are now more rigid and almost clear and colorless, and the abdomen is much straighter.

12:15 AM ... the wing's first tentative flutters ...

... and a minute later at 12:16 AM the wings are held horizontally. Note the luster of the wings typical of teneral odonates (almost like plastic wrap). At 12:21 AM the dragonfly was capable of weak flight.

The time spanned by this sequence of images is one hour and twenty-seven minutes. In this relatively short interval the dragonfly has changed from a squat, brown, aquatic bottom crawler to a colorful winged incarnation (still predacious) capable of executing extraordinary aerial manoeuvers. The naiad was about 20 mm long, the length of the adult is about 40 mm. It's hard to believe they are one and the same entity, and except for this digital record of the transformation, all that's left is this little souvenier of our brief encounter ...

Four-spotted Skimmer (Libellula quadrimaculata)

This dragonfly was photographed at the north shore of Stoco Lake. The males and females are similar for this species. I also sighted a Common Whitetail (Plathemis lydia ... or should that be Libellula lydia?) in the same area but it wasn't inclined to pose for a picture. Maybe better luck next time ...