Saturday, September 20, 2014

Amethyst Aster (Aster x amethystinus)

A hybrid between two very different looking species, the New England Aster (Symphyotrichum novae-angliae) and the Heath Aster (Symphyotrichum ericoides), the Amethyst Aster (Aster x amethystinus) exhibits characteristics of both parent plants which, not surprisingly, were abundant in the high and dry field where the Amethyst Asters were encountered.

The following groups of three photos illustrate the features of the Amethyst Aster, New England Aster and the Heath Aster respectively.

The overall aspects of the plants.

The blossoms resemble those of the New England Aster but are only about half as large and bear fewer ligulate flowers.

Even the involucral bracts or phyllaries are intermediate between those of the progenitor species.

More studies of the Amethyst Aster – the relatively small leaves are crowded and clasp the stem.

The main stem of the plant is hairy.

Wednesday, September 17, 2014

A Late Season Common Whitetail

Encountered west of Tweed near a marsh bordering the trans-Canada Trail (44.46889°, -77.31528°) – a surprising find as the final few surviving Common Whitetails (Plathemis lydia) were flying nearly a month ago, and no others have been sighted until now. The last sighting in this area was a male on August 18, 2014 near the intersection of River St. and the trans-Canada Trail (44.473668°, -77.312911°).

The dulled colors aside, this female is in really good condition with no wear and tear on the wings, it was extremely wary and alert and it sure could fly. Half an hour of patient stalking were required to capture the agile odonate.

As of today – September 17th, 2104 – the dragonfly is still alive and well. Sad to say, her days are numbered. Even if she manages to evade the Darners patrolling the marsh (six species currently known – and lots of them!) the first frost of autumn lies in the not too distant future ...

Adult dragonflies can live for a few weeks if they don't fall victim to predators or the elements. Looking at the lackluster colors of the eyes and thorax and the frayed wings of this male Common Green Darner (Anax junius), one can only wonder how old it might be.

An superannuated female Lance-tipped Darner (Aeshna constricta). Again, the coloration and patterning – originally a beautiful yellow-green – is obscured, the cerci are broken, and the wings have obviously seen their fair share of use and abuse.

The colors of this male Canada Darner's (Aeshna canadensis) are fairly bright and only the whitish discoloration and ragged edges of the wings suggest its age.

The dragonfly's face, however, was something of a shock – the brown clypeus is hardly typical of this species. Discoloration of the exoskeleton due to old age? Or an aberrantly colored individual?

Tuesday, September 16, 2014

Lake Darner (Aeshna eremita)

At first glance the Lake Darner looks very similar to the Canada Darner. The main distinguishing characteristics are the distinct dark cross-stripe on the face, the very deeply notched anterior thoracic stripe and a second thoracic stripe that is relatively broad compared to other Aeshna species.

On the average Lake Darners are larger than Canada Darners; this male measured 75 mm in length. In addition the cerci of Aeshna eremita are strongly bent upward and bear prominent bumps on the upper surface, but without a Canada Darner handy to compare these features to the differences were not obvious in the field.

A female Lake Darner, at 72 mm almost as long as the male encountered on September 15th. The field marks are right on the money and identical to those of the male, with a notched (the notch being nearly semi-circular) first thoracic stripe and wide second thoracic stripe ...

... a central line on S2 joining the band on S1, and fused blue spots on S10 (the male deviated on this feature, his were touching, but just barely).

A closeup of the face depicting the cross-stripe.

The terminal appendages (cerci) are rounded at their tips and similar to those of the female Canada Darner. Again, note the fused blue spots on S10.

Details of the genital plate and styli, however, these features aren't useful for separating this darner from other related species (at any rate, they are not mentioned in field guides).

The Lake Darners encountered thus far have been unbelievably tame. The female had captured an insect and, looking for a place to sit and eat it in peace, tried perching on my face twice. A male (perhaps attracted to the female?) stopped to perch in the tall grass within arm's reach as the female was being photographed.

Saturday, September 13, 2014

A Stinkhorn is Born

Theoretically, in the best of all possible worlds a stinkhorn can expand from its immature "egg" stage to full size within thirty minutes. It actually takes several days to produce the nascent fruitbodies (primordia), but once formed, the fungus can bulk up rapidly by taking in water.

The following series of photos illustrating the growth of a Ravenel's Stinkhorn (Phallus ravenellii) spans about seven hours, maybe not fast enough to win any medals in the Fungal Olympiad 100 mm dash, but still a respectable rate of growth.

10:09 AM

10:52 AM

11:30 AM ... soon enough there were flies were checking out the sticky – and despite its obnoxious odor – sugary goo, which also contains the spores.

12:02 PM

12:37 PM

1:45 PM

2:54 PM

3:21 PM

4:59 PM

There was already an older stinkhorn to growing to the right of the "newborn"; the pair of fetid fungi made their presence known at a distance of a good three meters and no doubt insectile senses could detect the stinkhorn's odorous advertisment from a much greater distance. A carpenter ant and two species of flies paid a visit, and upon departure the insects took tiny samples of the spore mass with them, sowing the genes of the phallic fungi far and wide.

A few other fungi were present on the lawn, such as these Xylaria polymorpha, more commonly called Dead Man's Fingers, and they do indeed resemble four fingers – and a thumb – poking out of the ground.

This cluster of Bird's-Nest Fungi has seen better days and is too old to identify as to species. The "eggs" (periodoles) – each containing thousands of spores – that usually occupy the bottoms of the cups or nests (peridia) are long gone, leaving only their impressions in the bottoms of the cups. Like the stinkhorns, Bird's-Nest Fungi deviate from the usual fungal scheme of relying on the wind for spore dispersal. The "eggs" are ejected when a raindrop hits the "nest"; each egg has a sticky string (funiculus) that latches on to sticks, leaves and other woodland floor litter.

Should you happen to be a nematode worm, fear this fungus! Rather featureless and nondescript, it not only makes up for an unremarkable appearance with a tongue-twisting not so ho-hum handle – Hohenbuehelia angustata – it is also a predator, or more accurately, nematophagous.

Friday, September 5, 2014

Easily identified Aeshna

In contrast to the difficult to distinguish females of the Lance-tipped Darner and Black-tipped Darner, the following two dragonflies are distinctive and can often be identified in flight if seen at close range. The females of both species are colored and patterned pretty much like the the males.

Shadow Darner (Aeshna umbrosa), male – photographed in early September

Habitat – Tweed, Ontario: a marsh west of town, bordering the Eastern Ontario Trail (44.46889°, -77.31528°). Typical local wetland with rushes, Cattails, Arrowheads and other emergent vegetation, the predominant shrubs are Speckled Alders and various species of Willow
Behavior – prefers to fly over small open areas of water among the alders and willows

– the narrow yellowish-green thoracic stripes are recurved at the top (underneath the wings), resembling walking canes
– relatively small greenish abdominal spots, giving the dragonfly a darker aspect than other local Aeshna spp
– the spatulate cerci appear similar to those of the Lance-tipped Darner when viewed laterally, but are wider and look very different in dorsal view
– no cross-stripe on the face, or a very thin brown line at most

Mottled Darner (Aeshna clepsydra), male – photographed in early September

Habitat – Tweed, Ontario: Stoco Lake, east of the boat pier (44.474563°, -77.306227°). Sand and mud bottom, relatively shallow stagnant water, emergent plants such as rushes, White Water Lilies, Wapato and Pickerelweed
Behavior – forages low amidst the rushes and other emergent vegetation along the lake shoreline

– the lateral sides of the thorax are mottled in yellow, green and blue
– relatively large light blue abdominal spots, giving the dragonfly a much paler aspect than other local Aeshna spp
– the cerci are straight and unadorned, with a small spine at the tip
– the face has a dark cross-stripe

The Mottled Darner might be easy to identify, but it is a difficult dragonfly to find, an uncommonly encountered odonate at best. It was a real privilege to watch three of these dazzling darners foraging only a half a meter away, flitting just above the water among the emergent rushes near the boat pier (there were others flying further east among the rushes and Pickerelweed, but not close enough to be absolutely certain they were indeed Mottled Darners). The last known encounter in the Tweed area was on September 24th, 2009.

Tuesday, September 2, 2014

A Well Known Spider

A friend brought me this impressively large female spider – a good 25 mm in length – for identification, he said his porch was literally crawling with them. I had never seen anything like it before and after several fruitless Internet searches was none the wiser as to its identity.

The eye pattern is definitely Araneus.

Ventral aspect of the chelicerae


The photos of the spider were uploaded to BugGuide.Net and the mystery arachnid was quickly pegged as a Barn Spider (Araneus cavaticus). I'm reliably informed by many other people that this spider is by no means rare, in fact, it's very common on and under porches, in barns and other rural outbuildings – and yet my submission to BugGuide.Net is the first data point for Ontario.

In fact this spider is not only ubiquitous but has no small claim to fame – this is Charlotte A. Cavatica in the children's book Charlotte's Web, written by E.B. White.

Saffron-winged Meadowhawk (Sympetrum costiferum)

Attaining a length of up to 35 mm (± 2 mm), the Saffron-winged Meadowhawk appears larger in the field than the average Sympetrum spp, approaching the size of a Blue Dasher. This meadowhawk's behaviour also quite different from that of its cousins, it's wary and extremely difficult to approach, staying on the wing for long periods, and preferring to rest on the vegetation over the water rather than the shoreline plants.

The Saffron-winged Meadowhawk is reputed to be local and uncommon, and I had always considered it to be rare as it's seldom encountered in this neck of the woods, my last (and to date, only!) sighting was at Stoco Lake in early August, 2009.

But perhaps it isn't so uncommon after all, maybe successful "dragonhunting" is a matter of finding suitable habitat first and then looking for the dragonfly. Dry Lake, south of Marlbank near the intersection of Hog's Back Road and Moneymore Road (44.419895°, -77.107758°), is quite unlike other local wetlands – it's shallow and very calcerous, with a slimy, limy bottom, and several fen indicator plant species were present along the shoreline.

As often as not, different water conditions and plant life generally mean a different suite of dragonflies ... and on the afternoon of August 24, I lucked out and sighted two Saffron-winged Meadowhawks.

The sides of the Saffron-winged Meadowhawk's thorax are a rusty brown color, giving the insect a distinctly darker aspect in the field than other meadowhawks (we're talking about the mature male in these photos, females and young males are yellow-orange). According to the books the legs have fine yellow stripes, a feature lacking in this individual, but perhaps (this is guesswork on my part) this is an older insect and the marks on the legs have faded with age.

The veins along the front edges of the wings are saffron (this fades with increasing age), and the sides of the abdomen bear relatively thin black lateral markings rather than the large triangles of most of our other local Sympetrum species.

S8 and S9 usually have small black dorsal marks.

A mug shot.

The long pterostigmata are reddish-orange.

A ventral view of the abdomen and a closeup of the epiporoct.