Monday, September 30, 2013

Potentially good news for the Red Knot

Photo: Hans Hillewaert/Wiki Commons

FOR IMMEDIATE RELEASE
Contacts:
Meagan Racey, 413-253-8558, Meagan_Racey@fws.gov
Wendy Walsh, 609-646-9310, Wendy_Walsh@fws.gov

Service Proposes to List Red Knot as a Threatened Species Under the Endangered Species Act

Declining food supply and habitat are seen as threats for a remarkable shorebird that migrates thousands of miles each year

The U.S. Fish and Wildlife Service today released a proposal to list the rufa red knot (Calidris canutus rufa), a robin-sized shorebird that annually migrates from the Canadian Arctic to southern Argentina, as a threatened species under the Endangered Species Act. The proposed rule will be available for 60 days of public comment.

“The rufa red knot is an extraordinary bird that each year migrates thousands of miles from the Arctic to the tip of South America and back, but – like many shorebirds – it is vulnerable to climate and other environmental changes,” said Service Director Dan Ashe. “In some areas, knot populations have declined by about 75 percent since the 1980s, with the steepest declines happening after 2000. We look forward to hearing from the public with any new scientific information as we consider the proposal.”

After an exhaustive scientific review of the species and its habitat, Service biologists determined that the knot meets the definition of threatened, meaning it is likely to become in danger of extinction in the foreseeable future throughout all or a significant portion of its range. The knot, whose range includes 25 countries and 40 U.S. states, uses spring and fall stopover areas along the Atlantic and Gulf coasts. Changing climate conditions are already affecting the bird’s food supply, the timing of its migration and its breeding habitat in the Arctic. The shorebird also is losing areas along its range due to sea level rise, shoreline projects, and development.

A primary factor in the recent decline of the species was reduced food supplies in Delaware Bay due to commercial harvest of horseshoe crabs. In 2012, the Atlantic States Marine Fisheries Commission adopted a management framework that explicitly ties horseshoe crab harvest levels along the Atlantic Coast to knot recovery targets. The Service’s analysis shows that although the horseshoe crab population has not yet fully rebounded, the framework should ensure no further threat to the knot from the crab harvest.

International, state and local governments, the conservation community, beachgoers and land managers are helping ensure knots have safe areas to winter, rest and feed before or along their journey to the Arctic. These partners assist knots in a variety of ways, including managing disturbance in key habitats, improving management of hunting outside the U.S. and collecting data to better understand the knot.

In many cases, the knot’s U.S. coastal range overlaps with those of loggerhead sea turtles and piping plovers, as well as other shorebirds. Conservation actions underway to benefit those species’ coastal habitats will also benefit knots.

The bird is one of the longest-distance migrants in the animal kingdom. With wingspans of 20 inches, some knots fly more than 9,300 miles from south to north every spring and repeat the trip in reverse every autumn. While migrating between wintering grounds at the southern tip of South America in Tierra del Fuego and breeding grounds in the Canadian Arctic, the shorebird can be found in groups of a few individuals to thousands along the Atlantic and Gulf coasts.

Studies in Delaware Bay show knots nearly double their weight at this last major spring stop to make the final leg to the Arctic. One bird, called B95 from his leg flag, has been nicknamed the Moonbird, as researchers estimate his 20 or more years of migrations are the equivalent of a trip to the moon and at least halfway back.

Other knot populations winter in the southeast U.S., northwest Gulf of Mexico and northern Brazil. New information shows some knots use interior migration flyways through the South, Midwest and Great Lakes. Small numbers (typically fewer than 10) can be found during migration in almost every inland state over which the knot flies between its wintering and breeding areas. Other subspecies of red knot, including C.c. roselaari that migrates along the Pacific Coast to breed in Alaska and Wrangel Island, Russia, are not included in this proposal on the rufa red knot.

As required by the Endangered Species Act, the Service plans to publish a separate proposed rule identifying critical habitat for the red knot before the end of 2013 and expects to make a final decision on both rules in 2014.

The proposed rule, in response to a court-ordered deadline, is available for public comment through November 29, 2013.The agency requests a variety of information on the knot, from population trends to genetics and distribution.

Comments may be submitted through the following methods:
  • Federal Rulemaking Portal: http://www.regulations.gov. Follow the instructions for submitting information on docket number FWS–R5–ES–2013–0097.
  • U.S. mail or hand-delivery: Public Comments Processing, Attn: FWS–R5–ES–2013–0097; Division of Policy and Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, Suite 222; Arlington, Virginia 22203.

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Friday, September 27, 2013

Mantidfly: They don't make 'em much more bizarre than this!

One can only imagine the fits of rapturous ecstasy that washed over me when I saw this thing flutter by on a recent trip to Adams County, Ohio. Well, that may be overstating the case a bit, but I truly was pleased to see this mantidfly, and all the more happy in that it cooperated for photos. I have only seen a handful of these six-legged oddities in my years afield, and this time I was armed with an excellent macro rig.

Mantidflies look like the result of a mad scientist's experiment gone awry. It's as if Igor were sent to the spare parts bins, drunk, and returned with the wings of a dragonfly, the body of a paper wasp, the head of a damselfly, and the raptorial forelegs of a praying mantis. Then, the evil doctor welded them all together, and Voila! This is what we've got.

These insects have a lifecycle as bizarre as their appearance, and the hoops that they've got to jump through to make it to the adult stage may account for their seeming scarcity. I don't know of anyone who claims to see tons of mantidflies. There are only about four or five species in this part of the world, in about as many genera. Mantidflies are in the Order Neuroptera, along with lacewings, owlflies, antlions and that sort of thing. I believe this species is Dicromantispa interrupta.

As you may have inferred from the mantidfly's powerful-looking thickened forelegs, it is a predator. Hapless lesser bugs that wander too near are seized, and unceremoniously gutted and eaten with the mantidfly's odd little beak. I don't imagine they miss much, either, given the proportionately massive size of its eyes. The entire dangerous front end of this thing is attached to a strange-looking thorax that resembles a bone.

Things only get weirder as one drills into the mantidfly lifecycle. A female carpet bombs the plants with clusters of hundreds of eggs. She needs to dump a lot of them, as the chances of an egg making it to the adult stage are slim indeed. After a few weeks, a tiny larval mantidfly pops out, and lurks in the foliage awaiting a suitable host. When an appropriate spider (other mantidflies use bees or beetles) comes along, the fledgling mantidfly leaps aboard and firmly attaches itself to the underside of the arachnid.

If all goes well, the spider eventually hauls her dangerous cargo to the nest. Should the larval mantidfly mistakenly board a male spider, it'll realize its error and attempt to cross over to the female when and if the male finds a partner and commences mating. The larva's relationship with the adult spider is phoretic: it is just using the spider to hitch a ride. If by some minor miracle the larval mantidfly makes it to the Holy Land - a spider nest - it will then hop off and ensconce itself with the arachnid eggs. There it will morph into a grublike form and feed on the spider's eggs, eventually pupating and transforming to the strange adult insect seen in these photos.

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Wednesday, September 25, 2013

Beautiful slugs!

Someone's finger points out a tiny slug moth caterpillar. It appears to glow, and it does. A tactic for upping the odds of finding caterpillars, especially little ones, is to use a blacklight flashlight. Many species glow quite brightly when so lit, and the searcher can spot them from afar.

From this photo, the uninitiated could be forgiven for thinking that slug caterpillars are nothing. Inconsequential little specks hardly worthy of notice. Nothing could be further from the truth, as we shall see. Most of these photos were taken either this fall, or the last. All of these species are at least fairly common in parts of Ohio and occur throughout much of the Midwest.

To learn more about the fascinating world of slug moths, get your hands on a copy of The Slug Caterpillar Moths (Lepidoptera: Limacodidae), and Other Zygaenoidea of Ohio. You can get one RIGHT HERE. Sounds a bit heavy, I know, but it's easily understood and includes a wealth of info about the interesting world that follows in this post. One of the book's authors is Dennis Profant, who lives in the Athens, Ohio area and manages this EXCELLENT BLOG.

This is a Stinging Rose Caterpillar Moth, Parasa indetermina, and it is one of the more distinguished of the slug moths. Most of them are just little brown jobs. Cool, if you are into moths, but not extraordinarily flashy. The caterpillars from which they are spawned are a whole other story.

This is a Stinging Rose Caterpillar, and what an extraordinary insect it is. They remind me of sea slugs - something far too exotic to be wandering the leaves of an Ohio forest. These cats aren't finicky eaters - they are polyphagous: capable of eating the foliage of many species of woody plants. This one is on American Beech, Fagus grandifolia.

One of the better known slug caterpillars is the Saddleback Caterpillar, Sibine (Acharea) stimulea. Those columns of spines will getcha! Many a person has learned just how painful the chemically fortified spines of caterpillars can be after touching one of these.

If not the most bizarre of our slug cats, the Monkey Slug, Phobetron pithecium, would be ranked near the top of the list. They don't even resemble caterpillars, or any other animal for that matter. One theory is that Monkey Slugs mimic the shed skin of a tarantula. That seems absurd here in Ohio - where we have no tarantulas - but this group is primarily tropical and found in areas where tarantulas are common. Why look like the cast skin of a giant spider? Well, who wants to eat such things? Looking untasty can be an excellent defense in the caterpillar world.

The Spun Glass Slug, Isochaetes beutenmuelleri, is undeniably outrageous. They are opaque, and the caterpillar's inner workings can be seen through the exoskeleton, like some sort of science exhibit come to life. The appendages are copiously beset with glassine hairs, and I suppose they can sting although I've never handled one to find out.

Tiny but beautiful, this Purple-crested Slug, Adoneta spinuloides, is about the size of the illuminated slug in the first photo. Blown up via macro photography, it becomes a thing of great beauty.

The well-named Elegant Tailed Slug, Packardia elegans, poses for your narrator.

Skiff Moth slugs, Prolimacodes badia, have an unmistakable shape. It may be that they mimic a leaf gall to better blend in. This species is quite variable in the coloration of the dorsal (upper) surface.

Here's another Skiff slug, and this one is clad in brown above. This coloration causes it to look like a patch of dead leaf tissue, and it would be incredibly easy to overlook this small animal.

Subtly beautiful, a Yellow-shouldered Slug, Lithacodes fasciola, feeds on a maple leaf.

Always a crowd pleaser, the Crowned Slug, Isa textua, looks a bit like a snowflake. This caterpillar is an outstanding example of the rewards of looking closely at VERY SMALL THINGS.

Finally, we'll end this slug parade with an utterly astonishing species, the Spiny Oak Slug, Euclea delphinii. They can vary in coloration from orange to pink to red, green, or yellow. No matter what color, it is a spectacular beast and sure to cause anyone to stop for a moment and inspect it.

There is still a week or two of good caterpillar hunting in this part of the world. Next time you're out and about in a wooded area, take time to inspect the undersides of leaves and you may run across some of these spectacular slugs.

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Monday, September 23, 2013

Copperhead, on a dark Kentucky backroad

A full moon brightens the inky darkness of a backwoods Kentucky night. I spent a few days over the weekend past exploring the Red River Gorge area, and did a lot of nocturnal exploring. The Harvest Moon sure seemed to bring the critters out; the nighttime woods were crawling - literally - with animals.

My primary quarry was caterpillars, and they did not disappoint. This is a Waved Sphinx caterpillar, Ceratomia undulosa. It, and one of its brethren, were feeding on a white ash. To seriously seek caterpillars requires going out after dark. Most cats secrete themselves quite well during the day, waiting until the cover of darkness to emerge and feed. Many of their predators - wasps, tachinid flies, birds - pack it in after dusk, allowing caterpillars a greater likelihood of remaining uneaten or unparasitized as they slowly eat through the foliage.

The ash that produced the Waved Sphinx was a "super tree", and also harbored this gorgeous Fawn Sphinx, Sphinx kalmiae. Caterpillar-seekers lust for such trees, which may have an abnormally high nitrogen content, or some other positive factor that induces moths to lay their eggs on them in great numbers. One can look at tree after tree of the same species, and see very little. Then - BINGO! A super-tree, full of caterpillars.

While roaming around at night, it's impossible not to notice all of the other members of the night shift. A hidden army emerges, both prey and predator. Caterpillars would most definitely constitute the prey. This beast - absolutely a predator, and a rather high-end one. It is a fishing spider in the genus Dolomedes, possibly D. tenebrosus. They have a tendency to rest motionless and head down on tree trunks, rather near the ground. I would not want to be the lesser beast that attempts to climb the trunk, unaware of this palm-sized spider.

Beautiful but deadly, an ornately marked assassin bug works the leaves. Note its proboscis. A quick stab with that, and it's curtains for whoever is on the receiving end. Assassin bugs often take young caterpillars.

Some of the predators are cute, such as this American Toad. Toads galore were out on this particular night - I must have seen over 100. This warty little guy was snapping up various small bugs that bumbled into his sphere.

This was the crown jewel of predators on this night, though. I was slowly navigating my car down a seldom-used gravel lane high on a ridgetop when a pair of snakes created a mad shuffle on the verge. I stopped and leapt from the vehicle for a better look, and was delighted to see a beautiful pair of Northern Copperheads, Agkistrodon contortrix! Both animals are together in this shot, and I believe that's the male on the right.

We move in closer for a good look at the coppery head of the male, complete with cat eyes. A handsomer snake would be hard to find. It is venomous, of course, and copperheads should be treated with utmost respect. I was safely out of their zone of discomfort, and neither snake threatened me. I've come across many copperheads, and have never had one act aggressively. But, I've always seen them before I was too close for an incident to occur. Most bites probably occur when someone reaches into a hiding spot sight unseen, and surprises the snake. The effects of a bite are unpleasant, but rarely if ever cause death.

Anyway, it appeared that I had stumbled into an amorous couple. The snake pictured above seemed to be the aggressor, and it looked like it was pursuing the other. When I rudely came on the scene, it was the one that held its ground, while the other copperhead slithered into a nearby cavity at the base of a tree. Northern Copperheads apparently mate in both spring and fall, and fall-mating females can delay gestation for several months.

If Senor Copperhead was successful in his pursuit of the girl, this will be the result. I photographed this yearling copperhead last year in southern Ohio. Copperheads are live-bearers, and the newly minted snakelets are carbon copies of the adults. Except for the rather bright greenish-yellow tail tip, which can be seen in the far left of the photo. Young copperheads eat amphibians, lizards, and insects, and supposedly use their colorful tail tip as a lure to attract prey.

All in all, an excellent night in the dark woods.

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Wednesday, September 18, 2013

Purple False Foxglove

The short-grass prairies of Erie Sand Barrens State Nature Preserve, awash in golden and purple. The yellow flowers are those of Gray Goldenrod, Solidago nemoralis; the purple belong to Purple False Foxglove, Agalinis purpurea.

I found myself at this obscure but stunning preserve in northern Ohio recently, and was pleased to see the place looking in fine shape. It had been twelve years, probably, since I had set foot here. A botanical highlight was the expansive drifts of the foxglove, and I was struck with the urge to bring some of the plants back, in pixelated form. Some of those efforts follow.

A luxuriant foxglove provides an elegant counterpoint to the pinnate leaves of Partridge-pea, Chamaecrista fasciculata. The Purple False Foxglove is not a weedy thing, tending to occur in higher quality meadows uninfested with nonnative fare and often surrounded by other interesting native flora.

Point blank down the gullet of a foxglove flower. Note how the inner corolla is striped, and stippled with reddish dots. These are nectar guides; neon signs advertising for pollinators.

And in comes one, perhaps Nature's premier pollinating machine, at least in this neck of the woods. A large fuzzy bumblebee in the genus Bombus; an animal that supposedly lacks the appropriate aeronautics and engineering to get aloft, if you were to computer-model the beast. But fly they do, albeit in a noisily bumbling fashion, from flower to flower.

The bumblebee forcefully plops onto the foxglove's bloom, and commences to douse itself with granular pollen dust. These winged bags of fur are every foxglove's dream - a sure ticket to pollen transfer and outcrossing.

Bumblebees are not the only insects drawn to the allure of the foxglove flowers. This is a flowerfly in the Syrphidae family, doing a remarkably good job of looking stingingly dangerous. It's a ruse - the fly is a mimic of a hornet, and even buzzes like one, but it packs no punch. It and the bumblebee were part of a long parade of interesting six-legged pollinators that were lining up for the foxgloves' nectar.

We even found a rare white form of the "purple" foxglove: Agalinis pupurea forma albiflora. This form has only the slightest rosaceous tint to the petals.

Places such as Erie Sand Barrens are vital repositories of biodiversity, their abundance of life all the more striking when compared to the monocultural wastelands of beans and corn that surround this site.

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Tuesday, September 17, 2013

Pretty but deadly: Flowers of doom

With A Flower
I hide myself within my flower,
That wearing on your breast,
You, unsuspecting, wear me too –
And angels know the rest.
I hide myself within my flower,
That, fading from your vase,
You, unsuspecting, feel for me
Almost a loneliness.
 
Tis the season of the mighty Asteraceae Family: asters, bonesets, goldenrods, sunflowers, etc. These harbingers of winter brighten the autumn meadows, and many a person remarks on fields painted bright with botanical gold, purple, and cream.

There is a deadly irony in the beauty of these wildflowers, however. Flowers are magnets for insect pollinators, and their presence is part of the charm of flower-watching. But for these nectar-seekers, the danger quotient ratchets up immensely when they alight on flowers. Predators are well aware that sooner or later potential victims will come to visit the flower patch, and they lay patiently in wait.

The robust creamy-white inflorescence of Tall Boneset, Eupatorium altissimum, is quite alluring to all manner of six-legged pollinators. If one of them chooses to work this plant, they had better watch their step. Look carefully and you'll notice three or four tiny bits of dead-looking flower.

Those brownish patches among the boneset flowers are anything but dead plant tissue - they are ambush bugs, a pollinator's worst nightmare. Here we have a Pennsylvania Leatherwing beetle cresting the dome of these flowers, and walking right into a trap. Look carefully: an artfully disguised ambush bug, Phymata pennsylvanica, lays in wait.

This beetle was lucky, or perhaps its size and armoring was just too much for the ambush bug. The latter made a stab at it, quite literally, but the beetle scuttled off intact.

Many bugs are not nearly so fortunate as that leatherwing beetle. I came across this scene two autumns ago. Spotting the little flower wasp from some distance, I stalked in for photos. No stalking was necessary. It had been captured and punctured by an ambush bug! These ferocious hemipterans lunge from the blossoms - an evil flower sprung to life! - and grab their victim with daunting raptorial forelegs. A quick jab with a syringelike proboscis injects chemicals which instantly disable the prey, and dinner is served.

Ambush bugs are common throughout Ohio and the Midwest, and with the exception of the previous wasp photo, I have made all of these images in the last week or so. These fascinating predators are not difficult to find, but obviously are easily overlooked. Their ability to match a flowery substrate is remarkable; the bugs are typically dappled with brown patches to mimic dead plant tissue. This ambush bug, another Phymata pennsylvanica, I believe, illustrates this perfectly as it tees up on a fading Gray Goldenrod, Solidao nemoralis.

Everyone should have a personal favorite ambush bug, and this is mine - the so-called Goldenrod Ambush Bug, Phymata americana (at least I think I am correct on these specific identifications; feel free to correct me if you know better). Goldenrod Ambush Bugs are a buttery yellow, and match the goldenrod flowers to an almost magical degree. An unsuspecting bee, fly, or skipper could be forgiven for not noticing it. The ambush bug will not be forgiving, however, and Dickinson might even have modified her lovely poem had she known that such horrorshows lurk within pretty flowers.

Seen well, an ambush bug is bizarre indeed. They remind me of little gargoyles. Utterly inscrutable, and without emotion. If one of these things was the size of a black bear, we would be in grave danger. Note the huge Popeye-like forelegs, there to seize and immobilize surprised victims.

Here's an ambush bug, prodded out of cover for our viewing pleasure. A more remarkable insect is hard to imagine. Next time you are among a goldenrod patch, or other plants that produce dense masses of blooms, investigate carefully for these beasts. I'm sure you'll find some.

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Monday, September 16, 2013

An interesting little wasp

Last Saturday, I found myself strolling down the long linear Milford Center Prairie corridor - an abandoned railroad right-of-way - when an eagle-eyed member of my party spotted this gorgeous little case, hanging from a pendant thread. It resembled an Easter egg painted in black and white, albeit on a tiny scale. The case was only a few millimeters in length, and dangled from the branch of a Sandbar Willow, Salix interior.

I really had no idea what made it, but thought it might be a wasp, as some of them make similar cocoons. But my efforts to come up with an identification bore no fruit, so I turned to the amazing BugGuide megasite. Within minutes of posting this photo, I had my answer. Someone quickly identified the family of wasps, and from there it was easy to come to a specific ID: Charops annulipes (no common name).

The object in the photo is indeed this wasp's cocoon, and it hangs it from a thread for a reason, as we shall see.

Researching this issue reminded me of a photo that I took in mid-August of last year, in another prairie remnant not far from where we found the cocoon. I dug back into the files, and quickly found this photo, which I had just labeled as "wasp". This animal was tiny, almost gnatlike in appearance, and I only managed two so-so shots before it darted off, never to be seen again. Well, I compared it to the relatively few decent photos that I could find of Charops annulipes, and this seems to be it!

Like so many of the micro-wasps, Charops is a stunner. I remember the encounter very well, and how I wished I had had a bit more time to compose better images. More than a few times I've spotted tiny parasitoid wasps hunting the foliage, and have been dazzled when I finally lock them into the sights of my macro lens. With the naked eye, they are nothing - inconsequential mosquito-sized bugs that would easily be passed by. The magic of magnification reveals amazing detail of structure and color. But then comes the problem of identification. The wasp world is utterly massive, and there are no comprehensive Peterson field guides to help. I have many mystery photos labeled as just "wasp", as this one was.

Charops is a parasitoid, and lays its eggs on the caterpillars of moth species such as this snout (I believe it is the very variable Green Cloverworm, Hypena scabra). The wasp probably preys on other Noctuid moths as well. It's the same old grisly story - wasp larvae burrow into the host caterpillar, and eat it alive.

But turnabout is fair play, and apparently Charops can fall victim to its own set of parasitoid predators. Hence, the cocoon suspended in space by a thread. Dangling in midair makes it harder for would-be predators to find and reach the wasp cocoon, thus upping Charops' chances of survival. Or at least that's how I understand this elfin wasp's lifecycle.

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Sunday, September 15, 2013

Giant Swallowtail: An ugly duckling tale

One of the world's most popular fairy tales is The Ugly Duckling by Hans Christian Andersen. That tale involved a homely bird chick that grew up to be a beautiful swan. The animal highlighted in this post is the lepidopteran counterpart to Andersen's swan.

A spindly little Wafer-ash, Ptelea trifoliata, springs from the ground, its interesting leaves marred by an unsightly bird dropping. But wait! We better look again...

That's no bird dropping - it's a caterpillar! We're meeting one of our strangest butterfly larvae, that of the Giant Swallowtail, Papilio cresphontes. Scores of insects - and some spiders - mimic the appearance of fresh bird poop. Looking like scat can be a good thing, because few predators like to eat bird droppings. So laying on top of a leaf, looking like the fresh aftermath of a Blue Jay's meal, can help an organism to hide in plain sight. Bird dropping-stained leaves are everywhere, and mirroring the look of fecally tarnished foliage is a great way to outwit your enemies.

No one does the bird dropping masquerade better than the caterpillar of the Giant Swallowtail. If there was an Oscar for Best Actor in Fecal Disguise, this would be our winner. These cats are big ones, too, at least when the caterpillar is in its last instar, or growth stage, as is the one pictured in these photos. I was fortunate enough to encounter this Giant Swallowtail caterpillar recently in Adams County, Ohio.

Looking like a fresh, wet bird dropping isn't the only trick that this cat has up its tubular sleeve. If startled by a would-be predator such as a songbird, or possibly parasitoid flies or wasps, the caterpillar flicks out a chemical switchblade. You can often get the caterpillar to pull its weapon by gently tapping it on the back. In this photo, just after a light tapping, the caterpillar has reared its head in the direction of the offending tapper, and is exerting strange red horns called osmeteria. All swallowtail species caterpillars are armed with this piece of equipment.

In the blink of an eye, the besieged caterpillar protrudes its osmeteria to a remarkable length - quite an unexpected and awe-inspiring sight indeed! I would imagine, were you the size of a chickadee or perhaps a menacing insect, these horns being abruptly thrust into your face might just be enough motivation to go elsewhere.

If the physical appearance of these long horns isn't enough, the chemical secretions that they are coated in might do the job. To me, the osmeterial secretions smell rather foul. I was about three or four feet from the caterpillar when I made the photo above, and in no time my olfactory senses were assailed by a distinctly unpleasant odor. I can't imagine that the osmeteria and its associated chemicals hold any charm for birds, spiders, mantids or any other creatures that might threaten the larva.

If all goes well for the rather repulsive caterpillar, this will be the end result, a stunning Giant Swallowtail butterfly. This is the largest species of butterfly in Ohio, and the appearance of one will almost always elicit a positive reaction. The same type of reaction will generally not be offered for the caterpillar, unless the viewer is someone like me who likes and appreciates bizarre larvae.

Giant Swallowtail caterpillars feed on plants in the Citrus family (Rutaceae). In Ohio, that's only two species, the aforementioned Wafer-ash, and Prickly-ash, Zanthoxylum americanum. Neither are true ash, but are related to the orange. Some savvy nurseries that specialize in native plants offer at least the Wafer-ash (the Prickly-ash, true to its name, is quite thorny and less likely to be sold). Try planting some Wafer-ash on your property, and perhaps you can also grow these fantastic beasts.

Following are some Ohio nurseries that sell Wafer-ash:

Keystone Flora

Naturally Native Nursery (extra points for selling Prickly-ash!)

Scioto Gardens

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Saturday, September 14, 2013

Dragonfly swarm locales

 
I received a fair number of reports of dragonfly swarms, based on the last blog post, and other stuff that I've written about this phenomenon. The map above shows locations of the last few days' reports, and nearly all observers indicated swarms of "dozens", but more often "hundreds" or "thousands". From the evidence at hand, the vast majority of dragonflies involved were Common Green Darners, Anax junius. Most reports were made in the waning hours of the day - often near twilight.
 
These mapped locales represent but a fraction of the reports that were made. I saw numerous mentions of dragonfly swarms on Facebook and elsewhere. And two respondents to me live in Illinois, and saw massive swarms there. One can only imagine the untold millions of these big dragonflies that moved through the Midwest in advance of the current cold front. It would be fascinating to know with certainty where these animals are headed. Possibly the Rio Grande Valley of south Texas? Mexico? Deeper into Central America? My hunch is that they disperse on a broad front across the Gulf States and then south into Mexico and perhaps beyond. Hopefully, someday this migratory dragonfly mystery will be thoroughly unraveled.
 

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Thursday, September 12, 2013

Dragonfly swarms!

An interesting shot of a male Green Darner, Anax junius, in flight, courtesy of Dave Lewis. Props to Dave; freezing one of these fast-moving insects with the camera is not easy.

Ohio, and surrounding states I'm sure, have experienced a blitzkrieg of migrant dragonflies in the past few days. I've received about a dozen reports at work, a few more here at home, and have seen reports of dragonfly swarms on Facebook and other places. The vast majority of these dragonflies are the highly migratory Green Darner, as shown in Dave's shot above. These dragonflies are headed to points south, and pushing through in vast inestimable waves in front of the coming cold front.

I penned an article about this time of year in 2011, for my employer the Ohio Division of Wildlife. That column made its way to a number of newspapers, and is still findable on the net, apparently - it was the catalyst for a number of the reports that I received. Following is that piece, which goes into more detail about Green Darners and dragonfly migration. It is just as relevant to the current flight as it was a few years ago.

Invasion of the dragonflies

A fantastic insect invasion has been occurring recently. No worries – a plague of locusts hasn’t descended, nor are killer bees overrunning Ohio.

Our visitors are dragonflies: common green darners, Anax junius. Large swarms of these jumbo fliers have been reported from numerous Ohio locales and elsewhere in the Midwest in the past week or so.

Common green darners are easily recognized. They are one of the largest of the 160+ dragonfly species that have been found in Ohio. From stem to stern, a good-sized darner can measure 3 ½ inches, with a wing span of four inches. The thorax (main body) is a distinctive pea green. Males have a turquoise-blue abdomen (tail); in females the abdomen is rusty-brown.

This species is a common inhabitant of Ohio’s ponds and wetlands, and is found in all 88 counties. Like other dragonflies, their larvae – nymphs – are strictly aquatic. The bizarre, alien-looking nymphs remain under water for a year, hunting small animal life. When tripped by some internal alarm clock, the nymph emerges from the water shortly after dusk, climbs a plant, and begins an amazing transformation. The nymph’s husk is slowly split open by the young adult – termed a teneral – as it pushes its way out. Once it has broken free of its larval shell, the teneral darner quickly hardens and expands. By daybreak, the transformation into an adult dragonfly is complete and the green darner is ready to take flight.

And take flight they do. Incredibly powerful flyers, green darners spend much of the daylight hours on the wing, jagging about at impossible speeds as they snatch small flying insects from the air. While gnat-sized bugs form the bulk of their diet, the burly dragons can take down much larger fare. When opportunity allows, they’ll grab large horseflies, bees, and lesser dragonflies. They have even reported to take hummingbirds!

A big mystery shrouds the common green darner. This is one of our highly migratory insects, as is the monarch butterfly. However, the movements of green darners are not nearly as well understood as those of the monarch, and scientists are still unraveling the secrets of darner migration. In late summer, massive “flocks”, perhaps better called swarms, are sometimes seen. This year, darner swarms have seemingly been more numerous than usual, with many scattered reports.

It is a striking sight to witness hundreds or even thousands of these large dragonflies swirling about. Sometimes they are seen high aloft, moving together on a steady southward trajectory. On other occasions, swarms descend to low levels and actively feed over meadows and other open areas.

Where are they going? No one is sure, but it’s possible that the darners are moving to warmer climes of the southernmost U.S and Mexico. Green darners also appear to migrate back north in the spring, much as birds do.
 
A lot remains to be learned of dragonfly migration, and observations of large swarms are helpful to researchers. If you have witnessed a dragonfly swarm, please report it to Jim McCormac at the Ohio Division of Wildlife: jim.mccormac@dnr.state.oh.us or 614-265-6440. Please note the date, time, location, and ideally an estimate of the number of dragonflies.

A female Green Darner, at rest.

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