An Ambush of Tigers

Not a very coleopterological title, perhaps "A Scuttle of Beetles" would have been better in that respect. Tiger Beetles, however, are not known for their ability to scuttle. The larvae are indeed ambush hunters, hiding in burrows with only their heads exposed, hoping to grab a passing meal with their crescent-shaped jaws. Should they latch onto something too strong to handle they have hooks on their abdomens which serve to anchor them in their burrow until their digestive enzymes overcome their prey. And the equally predacious adults are agile runners and superb fliers, feeding on caterpillars, grasshoppers, spiders and whatever other arthropods they can catch.

Despite their competence as hunters tiger beetles are by no means apex predators – they also need those long legs and strong wings to evade birds, toads, robber flies and dragonflies. And speed isn't enough to escape parasites such as mites, wasps and even certain species of bee flies. (Sometimes I just sit and observe predators, prey, parasitoids and parasites interacting, eating and competing with one another ... and wonder how anything survives ...)

At roughly 12 mm in length the metallic blue-green Six-Spotted Tiger Beetle (Cicindela sexguttata) is of average size, but definitely stands alone among our local tiger beetles in terms of color.

A front view showing the pronged, interlocking jaws ... an insect unlucky enough to caught in them isn't getting out again.

The Big Sand Tiger Beetle (Cicindela formosa generosa) is about 18 to 20 mm long, making it the largest tiger beetle I've encountered to date – it makes an audibly droning sound when taking flight.

A portrait taken in the shade. At first glance the patterning which camouflages tiger beetles so well may appear dull, but up close the light and dark brown resolves into a myriad of brilliant colors.

At the opposite end of the size spectrum, only about 10 mm in length and relatively drab compared to its cousins, is the Punctured Tiger Beetle (Cicindela punctulata).

On Page #84 of the Peterson Field Guide to Beetles (Houghton Mifflin Company) the author, Richard E. White, observes how "the light markings on the elytra of many Cincindela species ... provide a good example of evolutionary development of color pattern." – specifically noting (among other species, which I unfortunately don’t have photos of) C. scutellaris, C. repanda, C. tranquebarica. It is interesting to note that C. sexguttata, C. formosa and C. punctulata, pictured above, also share similar or attenuated versions of the basic pattern.

The aptly named Festive Tiger Beetle (Cicindela scutellaris) makes up for the lack of decorative patterning on its backside with gaudy iridescent colors. This tiger beetle and the following two species are all about 12 mm long.

Tiger beetles can be opportunists. Although quite capable of doing so this beetle didn't hunt for its meal – it stole the grasshopper from a Tachysphex wasp that had stung and paralyzed it to feed its own offspring.

Like other tiger beetles, the Bronzed Tiger Beetle (Cicindela repanda) has a penchant for sunshine, heat, and barren terrain, however, it's more likely to be found hunting on the sandy beach along the lake shoreline.

Always look twice! At first I mistook this Oblique-lined Tiger Beetle (Cicindela tranquebarica) for a Bronzed Tiger Beetle. But compare the first markings on the elytra of these two insects – the diagonally oriented, rather than c-shaped marking, earned this tiger beetle its name.

One "tiger" I haven't had luck acquiring an image of, very similar to the two above, is the Hairy-necked Tiger Beetle (Cicindela hirticollis). But then again, a couple of years ago I had no idea there were so many species of tiger beetles in our area. That's the great thing about getting out there in the field and observing and photographing nature ... there's always something new to learn, and never a dull or boring moment ...

Williamson's Emerald (Somatochlora williamsoni)

According to Dragonflies and Damselflies of Algonquin Provincial Park and the Surrounding Area, Williamson's Emerald (Somatochlora williamsoni) is widespread but uncommon and it's a shame that this teneral male never had the opportunity to reproduce. The dragonfly was the victim of a collision with a vehicle and expired a few hours before these photos were taken; the beautiful, foil-like metallic yellows and greens have already begun to fade upon the death of the insect.

Williamson's Emerald is a fairly large dragonfly with a length of about 55 mm.

The are claspers are somewhat hairy and turn up at the tips, with a lateral spine visible along the outside edge when viewed from above.

Looking like Crap

This is not necessarily a bad thing, certainly not when you are a potentially tasty meal surrounded by dozens of predatory species often much larger and faster than yourself. In the unforgiving realm of nature the demands of survival take precedence over vanity, and unlike we, the people, insects don't have the luxury of worrying about the latter, their only goal is to live at least long enough to pass on their genes to the next generation.

A Small Bird-dropping Moth (Ponometia erastrioides) ... the name says it all. The usual color scheme is a mottled mixture of white with reddish-brown and/or black, combined with a lumpy irregular profile.

Schlaeger's Fruitworm Moth (Antaeotricha schlaegeri)

A mating pair of Pearly Wood-Nymphs (Eudryas unio)

White Banded Fungus Weevil (Eurymycter fasciatus)

A winged adult insect can always take flight as a last resort if the poop ploy fails. Larvae don't have this option and many strive look even more convincingly like bird droppings, such as this Giant Swallowtail (Papilio cresphontes) caterpillar which comes complete with a glossy finish.

Should relatively small predators such as ants or spiders persist in their attentions the caterpillar has a secondary line of defense, the osmeterium, the "horns" seen in the following two photos. This gland is covered with a repellent 40:60 mixture of isobutyric acid and 2-methyl butyric acid – thus saith the various sources on the Internet, I didn't have my chemistry set with me.

Faking a piece of crap isn't solely about color, attitude and posture are also important. This White Admiral (Limenitis arthemis) larva curls its front end to imitate the appearance of a bird dropping. Hopefully this "ugly duckling" will live long enough to pupate and eventually metamorphose into an adult.

Although very different in appearance the Viceroy (Limenitis archippus) is closely related to the White Admiral. (The quite palatable Viceroy is, of course, mimicking the toxic Monarch.) Except for the brown being replaced by a grungy green the caterpillars definitely resemble one another – as well as bird droppings. Also note this caterpillar's posture – feeling threatened by my presence, it is keeping its head down while holding its convincingly head-like non-vital tail end in the air ... just in case its crappy camouflage fails ...

The larval stage of Tenthredo grandis, a species of Sawfly (order Hymenoptera) related to the bees and wasps. Is this pattern meant to fool a hungry bird, or does it serve some other purpose? It is somewhat too regular when compared to the butterfly larvae above, but who knows, maybe its good enough.

And I've always wondered about the pruinosity on a male Chalk-fronted Corporal (Ladona julia). These dragonflies prefer to perch in open sunny places on the ground. Are those chalky white markings meant to look like splats left by a passing bird?

Early Goldenrod (Solidago juncea)

... a continuation of the study and comparison of our local goldenrod species started last autumn. As its name implies, Early Goldenrod (Solidago juncea) is indeed an early bloomer and by the time I decided to see what's out there in terms of species of Solidago it was way too late to get any photos of this flower.

Early Goldenrod prefers sunny, dry, open fields.

This is the first of the goldenrods to flower; the photos of the flower buds below were taken in late June.

Another characteristic of this goldenrod is that the basal leaves – quite large basal leaves, and lots of them – are present when the plant is flowering.

A look at the stem and stem leaves.

By July 2nd a few of the petals are unfolding ...

... and on July 6th – voila! – the flowers are open.

Early Goldenrod grows to a height of about 150 cm.

Coming up next – Late Goldenrod (Solidago gigantea). Which doesn't bloom all that "late", in fact, it's next in line after Early Goldenrod and actually flowers before Canada Goldenrod and the other autumnal Solidago.

American Snout (Libytheana carinenta)

The American Snout (Libytheana carinenta) is a rare migrant to my area and I was lucky indeed to stumble across three of these unusual butterflies within a few days of one another. The larval host plants are various species of hackberry, and there is Common Hackberry (Celtis occidentalis) growing near both sites where the insects were encountered.

June 27th, 2012 at 44° 28' 35" N, –77° 18' 01" W ... the butterfly landed right in front of me. A beautiful specimen, and the lighting couldn't have been any better. But my good luck was followed by bad – for whatever reason the "Auto" setting on my camera focused on the background rather than the butterfly, so all I have to show for my efforts is a blurry butterfly with grasses twenty feet further away in perfect focus.

My second sighting of an American Snout occurred on June 30th, 2012 at 44° 28' 57.20" N, –77° 17' 47.33" W. This insect's wings were somewhat worse for wear but at least I was able to obtain a satisfactory image ... a far cry better than a blurry image of a perfect butterfly.

Libytheana carinenta #3 ... on July 10th, 2012 at 44° 28' 53.48" N, – 77° 17' 51.95" W, a bit to the west of where I encountered the male with the damaged hind wing. This is a different individual because both hind wings are intact (I was unable to acquire a photo of the right-hand side of the insect).

American Snouts aren't the first wanderers to drift through here this season. On June 25th, 2012 a Common Buckeye (Junonia coenia) was encountered at at 44° 28' 00" N, –77° 19' 11" W.

The leaves and distinctive bark of Common Hackberry, the larval food plant. The trees growing near the site of my second encounter were saplings and I was able to examine the leaves for evidence of caterpillars. Sure enough, something has been munching away, but no sign remains of what that something might have been.

Perhaps the caterpillar culprits were Hackberry Emperors (Asterocampa celtis). These butterflies have been flying for the past month, and lots of them – I spotted a good dozen last year and at least that many so far this season. A very "people friendly" species, Hackberry Emperors appear to be attracted to perspiration and aren't afraid to get it straight from the source ...