Eastern Least Clubtail (Stylogomphus albistylus)

Yesterday while counting dragonflies and damselflies along the shoreline of the Moira River, south of the dam, I spied an odonate the size of a Powdered Dancer – about 40 mm long – come in for a landing. Much to my surprise the "Powdered Dancer" proved to be a tiny Gomphid. It was extremely wary and flew off when I approached it to take a picture, and the following photo, a far cry from being the acme of digital art, was all I managed to get. I sighted the little dragonfly a few minutes later but again couldn't get close enough for a decent photo or a really good look at its markings.

I was fairly certain my mystery dragonfly was a female Eastern Least Clubtail and one of the experts at Ont-Odes was of the same opinion. I resolved, weather permitting, to return the following day armed with a net and binoculars and see if I could acquire better evidence toward a positive ID.

Not long after arriving I spotted one of the diminutive dragonflies perching on some rocks not far from the shoreline. The pale terminalia clearly contrasted with the dark background of the water, and I think this may have been a male (I doubt if the tiny nubs that constitute a female's cerci would have been visible looking through the binoculars). However, I couldn't really tell for certain if I was looking at claspers and when I approached with the net the insect took flight.

After another half an hour of patiently waiting a female landed right at the spot of yesterday's encounter (no doubt the same individual). She wasn't quite so alert today and I managed to capture her. She's on the older side, past middle age, and although not seriously worn her wings show a little bit of fraying at the edges. The dragonfly's length is 40 mm dead on (I used a straw on site and measured it at home later).

The Eastern Least Clubtail (Stylogomphus albistylus) is gracile dragonfly, and the tip of the abdomen is not prominently clubbed, even less so in females than males. The abdominal segments are boldly ringed with greenish-yellow.

A look at the beautiful – almost luminous – green eyes and prominent markings on upper surface of the thorax.

A mug shot – don't mistake that "grin" for a smile, she was not a happy camper and constantly kept trying to bite me.

Although the female's cerci are nothing like the intricately sculpted structures of the male, the terminalia are pale – almost white – in both sexes.

After the photo session the little lady was free to go her way in peace, or whatever little peace there may be in the odonate world. There was a Black-shouldered Spinyleg perching on the rocks in the same area, and though none were about today there are usually a few Dragonhunters patrolling the river. Both species are fast, powerful fliers and should one of these much larger clubtail cousins espy the Eastern Least Clubtail there's no doubt as to the outcome ...

So many things come down to nothing more than luck. Considering this dragonfly's habit of perching on emergent rocks in the middle of the river it's no wonder I've overlooked it despite surveying this spot fairly thoroughly for several years, and had it not been for yesterday's chance encounter I would still be ignorant of this gem's presence so close to home, practically in my back yard.

The barren, rocky river shoreline at the Vanderwater Conservation Area seemed like another promising place to search for the Eastern Least Clubtail, as the odonate species there are much the same as closer to home. On June 15th friend and I visited a location (44.38019°, -77.31537°) where in addition to the aforementioned shoreline there is also a forest, a woodland stream and a seep along the side of the road, and a dry meadow, all within tens of meters of one another, making for an interesting juxtaposition of habitats. And at a bridge not far from the Vanderwater Conservation Area (44.421932°, -77.306281°) he encountered and photographed a Rusty Snaketail (Ophiogomphus rupinsulensis).

August 08 was warm and sunny, it seemed like a perfect day to check out the Vanderwater Conservation Area and – jackpot! – at about 2:00 PM in the afternoon I sighted a male Eastern Least Clubtail. He was extremely wary and with good reason, as a Black-shouldered Spinyleg and a Dragonhunter were active in the area.

However, I waited patiently and sure enough he kept returning to his favourite spot. The dragonfly seemed to become accustomed to my presence and decided I wasn't a threat, and I was eventually able to get close enough to capture some images of this uncommon but beautiful little dragonfly.

A Dragonfly is "Born"

The word "born" is being used here with poetic licence, as dragonflies are not born in any literal sense of the word. In the course of their life cycle they go through incomplete metamorphosis, and don't be mislead by that word "incomplete". The metamorphosis is incomplete only insofar as odonates don't pass through a pupal stage, but otherwise the change is very complete indeed, and when one compares the naiad to the adult dragonfly it's hard to believe they are formed from the same DNA.

This is a Dragonhunter, Hagenius brevistylus, and with a length of 75 mm to 90 mm it's one of our larger dragonflies. As its name suggests in addition to large butterflies and moths Dragonhunters prey on other dragonflies. A picture is worth a thousand words, here's the story of a dragonfly's journey to adulthood, with the first signs of emergence occuring shortly before 11:40 AM ...

11:40 AM

11:42 AM

11:43 AM

11:45 AM

Time out for a brief interlude here – I've always wondered what the white "strings" (visible near the thorax) on the exuviae might be. I did read on a blog or website somewhere or other that they are involved with the changeover of the insect's breathing system, but couldn't understand what or how switching from internal gills to pairs of spiracles on the abdomen had to do with these string-like structures. So I posed the question in an Internet group, and here's the response ...

"The internal tracheal system is 'closed', which means that the spiracles (openings to the outside) are sealed in the nymph, but must obviously open at the time of the adult moult. The tracheal system extends throughout the body and in the adult opens to to outside through spiracles in the thorax and the abdomen. In the adult the thoracic trachea are very well developed because of the very high oxygen requirements of the flight musculature and hence the evidence of them in the exuviae is particularly obvious. How or if the naiads shed the lining of these tubes in their aquatic moults is a mystery to me. Perhaps the spiracles open at that time to allow moulting.

The internal tracheae serve as the transportation system throughout the body for the oxygen picked up from the water through the thin cuticle of the gill. (Yes, insect rectums are also lined with cuticle.) I don't know how much of a role in oxygen transport the blood plays, but in most larger insects other than bloodworms it is fairly minor. In damselfly naiads you can see the branches of the tracheal system throughout the external gills, hence the term 'tracheal gills'."

And there we have it. The naiad not only morphs from a wingless underwater crawler to one of the most superlative fliers in the natural world, and somehow that amazing prementum which shoots the jaw out to grab passing prey turns into the much different (but just as deadly, from an insect's point of view) jaw structure of an adult, but the insect's entire breathing system changes over as well. In a case like this maybe a picture isn't worth a thousand words after all, because it can only convey a pale shadow of what's really going on here ... and so much for the "brief interlude", now back to the show ... 11:47 AM ...

11:52 AM

11:58 AM ... the teneral dragonfly is free of the exuviae.

12:01 PM

12:11 PM

12:22 PM

12:48 PM

12:54 PM ... the wings are fully deployed. We left at this point and returned at 1:16 PM, by which time the teneral dragonfly had already taken its maiden flight into the shoreline shrubs. The time from when the naiad's exoskeleton first split to flight – about an hour and fifteen minutes.

The exuviae was collected for future reference, in fact it was the discovery of a Dragonhunter exuviae about two or three days old that suggested it might be a good idea to keep an eye out for molting naiads. Whilst this one was about half way through its growing pains another naiad crawled ashore to make its own transformation.

The flattened, dead-leaf-like Dragonhunter naiads and exuviae are unmistakeable, they are a good healthy 40 mm long and have the enlarged third anntennal segments characteristic of clubtail naiads (the two rounded nubs at the front of the head).

So folks – tune in and watch for the next exciting installment of this adventure, it's been ongoing for nearly 300 million years, and still happening at a wetland or river near you ...

The Dragonflies of Drag Lake

Drag Lake is located about 7.25 km west of Tweed , at 44.443129°, -77.391084° along the trans-Canada Trail according to Google Maps. The lake appears to be rock-bottomed – calcerous, judging by the surrounding geology – with relatively shallow water, and the parts of the shoreline are bordered by marshes. Some odonates can be particular with regard to their habitat requirements and for whatever reason the Dusky Clubtail is plentiful at this body of water.

With a length of 50 mm ± 5 mm, Gomphus spicatus is larger than the Lancet Clubtail (44 mm ± 5 mm). As its name suggests the Dusky Clubtail tends to be darker than its cousin, lacking the Lancet Clubtail's yellow dorsal stripe on S9.

However, the dragonflies can vary in color and Gomphids are notorious for their mutable chromatic complexions in any event, with yellow becoming green and eventually changing to bluish-gray with increasing age. Both the Dusky and Lancet Clubtails can sport a pale yellow streak on S9 making this unreliable means of separating the two species. For a positive ID it's necessary to examine the claspers and/or genitalia.

Like most Gomphidae a.k.a. Clubtails, Dusky Clubtails perch on the ground or other horizontal surfaces such as low leaves. They are fairly tame (the individuals in these photos were captured by hand) and can often be approached closely, whereupon the lateral spines on the male's cerci are clearly visible.

The cerci also have a distinct ventral spine.

The male's secondary genitalia, looking at this picture the words such as baroque, labyrinthine and convoluted come to mind ...

The abdomens of the females tend to be more robust than those of males. The distribution of the sexes was rather odd, with thirty one males but only two females being encountered.

A macro of the female's genital plate.

There were plenty of exuviae scattered along the shoreline but none belonging to the Dusky Clubtail were in evidence. Although unconfirmed as yet (the images are at BugGuide.Net) the largest exoskeletons probably belonged to Epitheca princeps, the Prince Baskettail – but no Prince Baskettails were seen flying.

EDIT ... the response from BugGuide.Net: if there are four setae on the edges of the palps (which there are) the exuviae belong to Epitheca princeps. Also, according to this key at Odonata Larvae of Michigan the dorsal surface of prementum should be setose, which is the case in the specimens. So Epitheca princeps it is.

Four teneral female Calico Pennants (Celithemis elisa) were also sighted perching in the tall grasses, and apparently this dragonfly also finds the atmosphere of Drag Lake convivial. The Calico Pennant is not uncommon at other wetland habitats in south-central Hastings County, but in the coming summer months uncountable numbers of these colorful little skimmers can be found flying at Drag Lake.

The Belted Whiteface (Leucorrhinia proxima) and the Frosted Whiteface (Leucorrhinia frigida) are another pair of dragonflies that can be tough to distinguish at a glance. They are very similar in size, coloration and patterning, and both species develop pruinosity on the first few abdominal segments.

This Belted Whiteface was captured near a marsh a couple of kilometers east of Drag Lake, and examination of the hamules (top) and claspers (bottom) is the best means of distinguishing it from the Frosted Whiteface.

A Few Notes on Water Nymphs

It's inevitable that the "bugs" which generally pique the interest of most people are the adult form of the insect. The colorfully patterned wings of a butterfly or the iridescent elytra of a beetle that catch our eyes do so because in many cases insects are flying around trying to attract attention – that of a potential mate. The colors might be aposematic, bright, bold and arranged in striking patterns, a warning saying "don't mess with me". Or as often as not, an insect gets noticed because it's just plain weird and bizarre, it's so different that it almost qualifies as an alien form of life.

Ditto for dragonflies and damselflies – they're generally large or colorful, and pretty hard to miss on a visit to a river, lake or wetland. But the reality is that the odonates we see flying around are actually near the ends of their lives, on average lasting for only a couple of weeks before succumbing to predation or bad weather. Larger dragonflies such as darners can spend two or three years in their larval state, and by focusing only on the adult insects one is missing out on understanding most of their life cycles and roles in nature.

The following notes and photographs, not to mention the rest of this blog, are the work of a beginner who has taken only the first few steps down the long and never-ending road of learning. If you've had a close encounter with a cool naiad that's new to you and you're looking for a definitive answer as to species you've come to the wrong place, instead, try one of the links to the keys for identifying odonate larva further down this page.

Damselfly naiads are generally smaller than dragonfly larvae and have three external gills at the tips of their longer, slimmer abdomens. This is the larva of a Pond Damselfly, family Coenagrionidae.

The naiads of family Lestidae tend to be larger. Based on the habitat where it was found – a vegetated marsh – this could be a Northern Spreadwing (Lestes disjunctus), Sweetflag Spreadwing (Lestes forcipatus), Slender Spreadwing (Lestes rectangularis) or Amber-winged Spreadwing (Lestes eurinus).

The riparian habitat and very long basal segments of this naiad's antennae indicate family Calopterygidae. There are two possibilities locally – the Ebony Jewelwing (Calopteryx maculata) and the less commonly encountered River Jewelwing (Calopteryx aequabilis). According to Odonata Larvae of Michigan – Key to the Calopteryx Larvae of Michigan ~ "... tubercles behind eyes prominent and acute ..." ~ looking at the oblique views the spine behind the eye is clearly prominent and acute. This is the aquatic avatar of Calopteryx maculata.

Dragonfly naiads are stouter and more robust than their damselfly cousins, and their gills are internal (in other words, they breathe through their asses). This is a typical dragonfly larva, and based the adults of the species observed at the heavily vegetated lakeshore habitat and the naiad's profile it's a Skimmer, family Libellulidae.

Dozens of exuviae can be found during the summer months at the same lakeshore habitat. It's often advantageous to study exuviae as opposed to larvae since they can be examined and photographed without fear of hurting or killing the insect. Based on their general outlines these are Libellulidae exuviae, probably one of the common larger species such as the Widow Skimmer (Libellula luctuosa), Halloween Pennant (Celithemis eponina), Eastern Pondhawk (Erythemis simplicicollis) or Blue Dasher (Pachydiplax longipennis).

Celithemis eponina ~ can be ruled out, its eyes taper to conical points.
Pachydiplax longipennis ~ lacks the prominent dorsal spines.
Erythemis simplicicollis ~ "... lateral spines absent ..."
Libellula luctuosa ~ best guess, but most of the information needed for an exact ID is not in the photo. Next year I'll try to keep an eye out for emerging adult dragonflies, and it shouldn't be too difficult to capture the exuviae.

Identification to the species level might be difficult, but dragonfly naiads and exuviae can be narrowed down to as to family based on their general shape. This relatively stout exuviae is another example of family Libellulidae, and according to the Odonata Larvae of Michigan – Meadowhawks it keys out as a Ruby Meadowhawk (Sympetrum rubicundulum).

The best means of being certain as to the identity of an exuviae is to observe the eclosion or emergence of the adult dragonfly. This exuviae was left ehind by a Whitface – Leucorrhinia spp. – probably a Frosted Whiteface (L. frigida) as it's by far the most common of the Leucorrhinia species observed at the marsh where the exuviae was collected.

And about an hour and twenty minutes before it was photographed, this cast-off exoskeleton was worn by a female Four-spotted Skimmer (Libellula quadrimaculata).

Early last month I posted images of some family Cordulegastridae naiads. The shape of the naiads is distinctive and unmistakeable, but I have yet to encounter adults of this species (whichever one it may be!) and without having discovered the naiads would have no idea they were in the area – a great example of why the study of the naiads and exuviae is worthwhile.

And three years ago I uploaded a sequence of photos (taken by Pauline Campbell) of a Dragonhunter making its final molt to adulthood. In this case the profile of the exuviae is not typical of most Gomphidae, the burrowing larvae of Clubtails tend to be somewhat slender rather than broad and leaf-like.

Cruiser naiads are long-legged and spidery in appearance. There are two possibilities in this area – the Swift River Cruiser (Macromia illinoiensis), and the more commonly encountered Stream Cruiser (Didymops transversa). Due to the limits of the camera's macro (Canon PowerShot A530) and lack of experience in knowing what characteristics to photograph and/or observe when in the field I was unable to resolve the identity of the naiad to the species level ~ Aquatic Insects of Michigan – Macromiidae - Cruisers.

However, the experts at BugGuide.Net identified this Cruiser naiad right down to the sub-species level (perhaps based on the length of the lateral spines on S9?). Depending on which book or authority you want to follow, it's a Swift River Cruiser a.k.a. Illinois River Cruiser.

You've got to love that cute little frog-like face ...

After the photo session the naiad was released. The insect's colors are much more vibrant in its natural setting, however, underwater photography introduces greens and blues reflected from the sky and water.

Darner naiads and exuviae have relatively large eyes, and long but robust abdomens. By studying the images of the prementum, labial palps and blades posted at BugGuide.Net, I was able to ID this exuviae as belonging to a Canada Darner (Aeshna canadensis).

There were about a dozen of these dark exuviae clinging to a bridge over the fast moving water of the Moira River. Three of the images below are of an exuviae that belonged to a female – note the ovipositor.

BugGuide.Net to the rescue again ... the cast-off exoskeletons were left behind by Fawn Darners (Boyeria vinosa). I should have figured, both by the general aspect of the exuviae and because I was starting to see adults flying.

Thus endeth this lesson in how little I know ... and there's still a long way to go ...