Thursday, June 26, 2014

Maple Callus Borer Moth

Found throughout eastern Canada and the US, Synanthedon acerni has a rather curious color scheme. The moth's shape and size, the patterning on the wings, and the bright orange tuft of hair at the end of the abdomen lend the moth the appearance of a male Scorpionfly.

The larval host plant is maple, Red and Sugar Maple will do although Silver Maple is preferred and there was plenty of the latter growing in the area where the moth was encountered. The larvae bore in the wood and eventually a callus forms where the tree is infested.

Tuesday, June 24, 2014

An Off the Wall Orbweaver

The Star Bellied Orbweaver certainly stands out from the crowd and deserves the "Coolest Local Spider" prize for its offbeat shape if not for size or color.

There are four species in Canada and the United States, and considering the possibilities enumerated at the BugGuide.Net Acanthepeira page it looks like this is Acanthepeira stellata. As their irregular profile and patterning makes them resemble a small piece of dead leaf or other plant debris, Star Bellied Orbweavers don't stand out so easily in the field and the only thing that gave this female away was the brightly colored Virginia Ctenucha moth hanging in her web.

A couple of closeup shots – this individual was about 10 mm long, roughly twice the size of the Star Bellied Orbweaver encountered a couple of weeks ago.

Tuesday, June 17, 2014

Megarhyssa atrata

Megarhyssa atrata is one of our largest Ichneumons, here are the stats from BugGuide.Net: "Female: body is 38 mm, ovipositor 130 mm, antennae 24 mm." That remarkable ovipositor is used to drill deep into wood and deposit the eggs on the larvae of Siricid wasps such as Horntails.

Not uncommon and often seen flying in woodlands in late spring or early summer, this Giant Ichneumon is hard to photograph because it always seems to be on a mission. This one found a dead tree to its liking and stopped to pose for a couple of pictures.

Wednesday, June 11, 2014

"If you wish to live and thrive, let a spider run alive."

The origin of this saying is a bit of a mystery. Is it an Old English nursery rhyme? An American Quaker saying? At least it contains more than a grain of truth (where would the world's ecosystems – and we – be without spiders?), and it's certainly better than the bit of folk nonsense – "Step on a spider and it will rain." One thing for sure, there are plenty of spiders running alive – in the grass, on leaves, on trees, under stones and on the water – almost anywhere you care to look.

The wonder is that spiders aren't noticed more often. True, some have lifestyles that require cryptic colors but many arachnids literally glitter and shine and are as dazzling as any butterfly or flower. Like this female Tutelina similis, for example. The photos simply cannot do justice to this spider, it's body, a whole 5 mm in length, is iridescent but the cephalothorax under the right lighting is a shimmering lilac color. Tutelina similis differs from the closely related Tutelina elegans in not having a white band around the abdomen.

Two tiny male spiders, about 3 mm in length, were in the vicinity of the female. Sure enough there was a connection – they were indeed male Tutelina similis (a male Tutelina elegans would sport black tufts of hair on its first tibia) and no doubt prospective suitors for her hand in marriage, metaphorically speaking, all eight of them ... and him with only seven ...

A male Habronattus decorus ... the name is certainly apropos, how does irridescent pearl grey and glittering rose sound for a color scheme? Again, the image doesn't convey how striking this spider is in reality . All of this is packed into a mere 5 mm ... yes, Jumping Spiders definitely take first prize for appearance and color.

Doing its best to imitate a bit of dead plant debris or a dry seed, Acanthepeira spp makes up in funky form what it lacks in cool colors. This Orbweaver is only about 5 mm long making it very easy to overlook, which of course is the idea from a predator/prey point of view.

Much like the origin of the saying in the title of this post, the identity of this ant-mimicking male arachnid is a mystery ...

... as were, until recently, the names of the following two spiders. But today, whilst researching the enigmatic ant-mimick I identified this male by stumbling across it whilst searching for something else – it's a Two-banded Antmimic (Castianeira cingulata). "Stumbling across" is used in a figurative and not literal sense, the spider is only about 6 mm long.

This pretty girl with the yummy name of Candystripe Spider (Enoplognatha ovata) was also IDed by random find (of the same blog!) on the 'net. Too bad she prefers to hide out in the shadows instead of showing off her colors.

Beautifully patterned in black and white, Neriene radiata, the Filmy Dome Spider, also prefers shady places. It's a male (note the enlarged palps) and it looks like he's molted recently because there's an exuviae in his web (look near the bottom of the first photograph).

It's easy to dismiss spiders and think of them, if not with outright fear and revulsion, as drab and uninteresting creepy-crawlies beneath our notice. Hopefully these photographs and the images elsewhere in this blog have shattered that illusion and illustrated the diversity of color, form, and the fascinating lifestlyes of spiders. They've been "running alive" for a cool 300 million years, that's a lot of time to be sifted though the sieve of natural selection and find their place in the tangled web of life on earth, and it's an ongoing process ...

Male Arrowhead Spiketail – trans-Canada Trail

East of Tweed along the trans-Canada Trail are three sand-bottomed woodland streams that are known to support Spiketails. There's a fourth habitat that looks eminently suitable but it hasn't been investigated as yet.

In early June of 2011 a female Arrowhead Spiketail was photographed near Alexander Street. Last August, Cordulegaster naiads – and plenty of them! – were discovered inhabiting another stream (they were still doing all right in mid-January). And earlier this spring naiads were found in a creek near the intersection of Sulphide Road and the trans-Canada Trail.

Studies of the larvae proved inconclusive as to whether they might be Arrowhead Spiketails (Cordulegaster obliqua) or Twin-spotted Spiketail (Cordulegaster maculata) but a couple of days ago Mother Nature gave a hint as to which species it might be ...

Of course, this doesn't rule out the possibilty that Twin-spotted Spiketails might be co-habiting with their cousins.

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 ...

Promethea Silkmoth (Callosamia promethea)

The Promethea Moth is common in most of its range, which includes south-central Hastings County in Ontario. Yet despite their large size and striking appearance these moths are seldom encountered due to their nocturnal habits, and when resting they hang out the trees where their patterning makes them difficult to spot. (Another seldom seen Saturniid is the Io Moth – live moths are few and far between but it's not uncommon to find the remnants of the wings of individuals that have been bagged by bats.)

This pair stood out like a sore thumb, but then again, as a rule one doesn't expect to see a pair of these moths in the grass at the edge of a parking lot ensuring their genes are passed on to the next generation. In the case of Callosamia promethea this happens from late afternoon until evening, and the eggs are laid at night.

The larvae eat the leaves of a variety of trees – maple, cherry, birch – this caterpillar was found on White Ash. In our area they pupate in early autumn, and the adults emerge in late May or early June to begin the cycle anew. Adult Promethea Moths don't have functional mouthparts and live only a few days, surviving on the energy stored in their tissues from their time as a caterpillar.

Promethea Moths are sexually dimorphic, with the male being smaller and much darker than the female, and lacking the chevron-shaped spots on the upper surfaces of its wings.

The wingspan varies from 75 mm to 95 mm, but the female seemed larger than this.

As if finding a mating pair of these large moths wasn't surprise enough, not fifteen meters away was another female taking shelter in an alcove. She looked like she had only recently emerged and was moved to the safety of a nearby park, as there was too much traffic, both pedestrian and vehicular, in the area.

To learn more about this beautiful insect visit Butterflies and Moths of North America.

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.