Caterpillars, Part II

Okay, back to our regularly scheduled programming - caterpillars! To see the explanation for all of this caterpillar imagery, SEE THIS POST. I plan on posting one more series of cool cats later.

A Drab Prominent (Misogada unicolor) on the underside of a sycamore leaf (Platanus occidentalis). It is an extreme specialist, eating only the foliage of this tree. The caterpillar is also a midrib mimic, with its white dorsal stripe similar to the midrib of the underside of a sycamore leaf. When not feeding, the caterpillar typically rests with its body aligned exactly with the midrib, as this one is doing.

A Hickory Tussock (Lophocampa caryae) under attack from a nymph soldier bug. The predatory insect will jab the caterpillar with its elongated proboscis and essentially suck the life from it. Predation rates in most caterpillar species are extreme, approaching 99% in some cases. This is why female moths often lay hundreds of eggs. It is necessary in order to get some of offspring through the predatorial gauntlet and to the reproductive stage. But this is also why caterpillars are such a major underpinning of food webs. I did not intervene in this case.

One of the more bizarre North American caterpillars, the Monkey Slug (Phobetron pithecium). It is said to mimic the look of a shed tarantula skin. Why would an insect mimic that, when tarantulas do not occur in its range? But the genus Phobetron is largely tropical and occurs where tarantulas are commonplace. And many of the migratory songbirds that might eat a Monkey Slug winter in such tropical regions. This theory also presumes that shed tarantula skins are not tasty and avoided by birds. Which they probably are.

Slug caterpillars sort of ooze along the foliage, courtesy of their sucker-like feet. Here's a Monkey Slug feeding/enveloping a leaf edge, as seen from below.

I've said this before (and probably will again) but most caterpillars are specialists, eating only a small suite of plants with which they have successfully coevolved. This one, the Moonseed Moth (Plusiodonta compressipalpis - now that's a multisyllabic mouthful!), is a hyper-specialist. It only eats the foliage of the moonseed vine (Menispermum canadense). The caterpillar is a wonderful bird dropping mimic, not an uncommon ploy in the caterpillar world. Apparently, nothing likes to eat bird droppings. If you believe in reincarnation, come back as a bird dropping if you don't want to be eaten.

This is an Ochre Dagger (Acronicta morula), a real gem of a larva. It is an elm specialist and the botanically savvy might note that this specimen is on a black walnut. That's because we, as I recall, found this one on the ground. No one could remember its host plant, and I wanted a shot of it on a plant, the walnut was handy, and Voila! Yet another inaccuracy on the interwebs. But we're here to admire the Ochre Dagger's good looks anyway, not floriferous backdrops.

The caterpillar of the Pawpaw Sphinx moth (Dolba hyloeus) is larval art. The caterpillar far outshines the large sphinx moth that it becomes (if all goes well). Another extreme specialist that only eats its namesake plant, Asimina triloba (Pawpaw).

A Red-washed Prominent caterpillar (Oedemasia semirufescens) noshes on a fairly fresh oak leaf. This species is a master of vegetative camouflage and a consummate leaf-edge mimic. When ensconced on autumnal foliage dappled with brown, necrotic patches, it can be nearly impossible to see, even though it is a sizable caterpillar. A great spot by the incredibly sharp-eyed and knowledgeable Norah Tempus.

A Sigmoid Prominent (Clostera albosigma) snacks on bigtooth aspen (Populus grandidentatus). It is a specialist on plants on the Salicaceae family, and mostly aspens and cottonwoods, although it is said to eat willow (also in this family). This was another great spot by Norah Tempus, on about the only aspen to be found where we were. It was a new caterpillar for me, and probably everyone else who was with us.

The utterly bizarre slug caterpillar of the Skiff Moth (Prolimacodes badia). It looks like a gall on a leaf. John Howard and I have often speculated that the small white dot on the lateral ridge not far up from the tail (the rear of the caterpillar is at the right) may mimic the egg case of a tachinid fly. Perhaps a female tachinid on the hunt would see such a mark on a potential victim and decide it already had been parasitized. Tachinid flies are parasitoids that lay eggs on caterpillar hosts (and many other insects). The larva soon hatches and bores into the caterpillar and commences to eat it alive from within. By the time the larva is ready to emerge, it can fill nearly the entire body cavity of the host. Needless to say, the caterpillar does not survive such an attack.

However, taking the wind out of that theoretical egg mimicry sail is the fact that a real tachinid fly egg case is right next to the "mimic" mark (just below and left). The fake egg case clearly did not deter this fly. The air exchange hole created by the fly grub within is just left of the apex of the center of the Skiff cat's body.

A truly amazing slug caterpillar (it's hard to avoid all of the superlatives when describing caterpillars) is this, the Spiny Oak Slug (Euclea delphinii). This is one of the less colorful forms. Some of them are clad in bright pigments of yellow, lime, red and orange.

The epithet of the scientific name, delphinii, bears mention as it is almost certainly a misnomer. I'm assuming delphinii is a reference to Delphinium, the genus of larkspurs. I'm about sure this caterpillar does not nor would eat larkspurs - Spiny Oak Slugs eat various woody plants, trees, primarily. Delphinium stems from Delphinus, Greek for dolphin. But I cannot see how anyone would be reminded of a dolphin when looking at this caterpillar.

Camo caterpillars and the birds that eat them

 

A Red-eyed Vireo (Vireo olivaceus) in a characteristic hunting posture. The bird is searching for its major prey, the caterpillars of moths. It has its head cocked upwards, searching the lower surfaces of the leaves above, as that's where many caterpillars hide during the day. Lepidopteran larvae - and those are OVERWHELMING moth caterpillars (not butterfly caterpillars) - are the vireo's major food source. During a long summer day, the roughly 130 million Red-eyed Vireos breeding in the U.S. and Canada consume something on the order of 4 billion caterpillars. Hard to believe but based on what is known of their foraging rate and dominant prey items, that's how the numbers shake out.

A Prothonotary Warbler (Protonotaria citrea) with a freshly harvested caterpillar (unsure of species). Almost all of the 38 warbler species that breed in eastern North America eats scads of caterpillars, and so do most groups of songbirds. So do some nonpasserine species, most notably the cuckoos. Many of these birds are migrants that winter in more southerly haunts, often in Central or South America, and migrate northward during the breeding season to exploit the eastern deciduous forest region's vast bounty of caterpillars. As this is crop is only seasonally available, many of these bird species must travel back to warmer climes for the winter - where they undoubtedly also consume great numbers of caterpillars.

If you are a caterpillar, you don't want to be grabbed and eaten by a bird. Evolutionary warfare between caterpillars and birds is probably the main driver of some incredible caterpillar camouflage. If you are a plant-eating caterpillar and can become ever more like the appearance of the plants that you feed on, the odds of surviving surely goes up. Birds are endowed with incredibly keen eyesight and are quite adept at spotting larvae. They still find plenty, and between the avifauna and all of the other predators that take out caterpillars, the survivorship can be as low as 1% in some moth species. So, every advantage that a caterpillar can get to thwart predators becomes very important.

Following are some photos, most from recent forays, that showcase examples of incredible botanical (and gall) mimicry by members of the larval crowd.

Late summer and fall foliage become dappled with color as the chlorophyll fades and leaf tissue begins dying. This plump Blinded Sphinx Moth (Paonias excaecata) caterpillar displays reddish patches that mimic autumnal foliage, in this case Hop-hornbeam (Ostrya virginiana).

This is a sister species of the caterpillar above, the Small-eyed Sphinx (Paonias myops), which also sports rusty dots that resemble necrotic leaf tissue.

This is a personal favorite of the leaf-edge mimicry crowd, a Double-toothed Prominent (Nerice bidentata). It is a specialist of elms, and in our part of the world that's almost entirely American Elm (Ulmus americana) and Red Elm (U. rubra). We find them on both of this species with roughly equal frequency. The back of the caterpillar is scalloped, much like the rough marginal serrations of elm leaves. As it eats into the leaf, the caterpillar becomes the leaf.

This is another elm specialist (mostly at least, it is also said to eat basswood), and its moniker is apropos: Elm Sphinx (Ceratomia amyntor). When at rest on the underside of an elm leaf, as above, the caterpillar typically aligns itself with the prominent midrib of the leaf. The caterpillar also has a raised stripe down the center of its back. The cat's lateral lines are arrayed at acute angles to its pseudo midrib and mirror the angled venation of the elm leaf. In effect, the caterpillar becomes a continuation of the leaf's veins.

Few can match the Checker-fringed Prominent (Schizura ipomoeae) caterpillar's ability to become one with the leaf. This one (the head is to the bottom) is consuming an old dogwood leaf and as is typical, the caterpillar is eating inwards from the leaf's edge. In essence, it becomes the leaf and spotting one of these can be quite difficult even when it is right in front of you. Sharp-eyed botanists might note the cat's scientific epithet: ipomoeae. That references a genus of morning-glories and is probably a misnomer, as this caterpillar probably never eats those plants.

Few do twig mimicry better than the caterpillar of the Dot-lined White Moth (Artace cribaria). They are virtually impossible to see as they lay plastered to twigs, despite being a hefty cat.

Another brilliant example of twig mimicry is the Yellow Slant-line Moth caterpillar (Tetracis crocallata). This is one of the inchworms in the massive Geometrid family, and many inchworms are twig mimics. When not feeding, they attach themselves to a twig of similar diameter and color, and often adopt an acute outward angle. In the case of this species, the head is jagged and pale yellow, exactly as a broken-off branch would appear.

A Redbud (Cercis canadensis) leaf, with what appears to be a raised reddish gall. Such leaf galls are commonplace, and can be formed by many organisms: bacteria, fungi, aphids, midges, wasps and others. Birds don't eat them, insofar as I know.

But wait! Closer examination shows that our leaf "gall" is not a gall at all. It is a Red-crossed Button Slug caterpillar (Tortricidia pallida). Slug moth caterpillars are fascinating as a rule, as are the "cute" little moths that they become. As caterpillars, many species appear to mimic the look of leaf anomalies such as galls, and they can be hard to spot.

This is just a tiny tip of the lepidopteran iceberg when it comes to caterpillar mimicry, much of which is presumably driven by sharp-eyed birds that attempt to feed ravenously on the caterpillar crowd.

Epic caterpillaring results in many cool finds

 

Cherry Dagger moth caterpillar (Acronicta hasta)

Shauna and I spent last weekend at the fabulous Highlands Nature Sanctuary in Highland County, Ohio, which is owned by the Arc of Appalachia. A bunch of us were there for our 12th annual "caterpillar safari", which is just a bunch of larvally-minded friends of ecology gathering to seek out the always fascinating caterpillars of moths (mostly) and butterflies (far fewer in numbers and diversity). Now is peak season for caterpillar abundance and diversity, and we prowled into the wee hours on Friday and Saturday nights, exploring interesting habitats. Most caterpillars are active nocturnally, so hunters of them must adjust their search hours accordingly.

Dozens of species of caterpillars were found and photographed, including this Cherry Dagger (Acronicta hasta). We brought lots of livestock back to the Arc's forest museum - our base camp - and from 10 am - 2 pm the public is invited in. Dozens of people got to see crazy larvae that they likely never knew existed. One should not underestimate the value of moth larvae (which the overwhelming number of caterpillars are). They are the primary organisms that convert plant matter into a digestible form of protein for birds and myriad other animals and underpin food webs.

Gray Hairstreak caterpillar (Strymon melinus)

We certainly do not ignore the occasional butterfly caterpillar that turns up, and this was a particularly interesting one. It is the caterpillar of the Gray Hairstreak (Strymon melinus), which specializes on feeding upon species in the Pea Family (Fabaceae). These cats resemble Mike & Ike candies and are tiny and easily overlooked.

This one is feeding on a tick-trefoil in the genus Desmodium. Many hikers know this group of plants by their triangular loments (fruit) that are thickly beset with stout hooked hairs. They evolved for mammalian dispersal, and that includes the clothing worn by humans. Those loments can be tough to get off and will even survive trips through the washing machine.

Here's what that Gray Hairstreak caterpillar in the previous image will (hopefully) morph into - one of our showiest butterflies. I say "hopefully" because the survivorship of caterpillars is astonishingly low. Just about everything wants to eat them and for some species of moths, at least, probably only one percent or so of caterpillars make it through the complete life cycle and to the mature reproductive stage. The rest become part of a great food chain. To compensate for such high mortality, butterflies and moths lay enormous numbers of eggs; a carpet-bombing strategy if you will.

Finally, a cool little-known thing about Gray Hairstreak butterflies. John Howard showed this to me a while back. Hairstreaks habitually rub their hind wings together, and the "tails" resemble antennae. Perhaps this pseudo face with its twitching antennae fools birds and other would-be predators who then lunge at the wrong end of the butterfly. While the hairstreak may lose parts of its hind wings, it might still escape to live another day and find a mate and reproduce.

Anyway, as John pointed out, if you can get directly behind the hairstreak and under it (that can take some effort), the lateral fringes form the illusion of orange eyes capped with long antennae, and even a frowning mouth below. Whether all of that evolved to spook visual predators I do not know, but whatever the case it certainly looks cool. And once a butterfly photographer knows this, they may find themselves spending much time attempting to get into position to get this shot.

Nature: Hot dog! The hickory horned devil is one giant caterpillar!

A hickory horned devil in a hotdog bun for scale/Jim McCormac

Nature: Hot dog! The hickory horned devil is one giant caterpillar!

Columbus Dispatch
September 18, 2022

NATURE
Jim McCormac

A hidden army reaches a crescendo about this time of year. Its tubular soldiers are largely out of sight and mind, but wage battle with vegetation on an epic scale. Mostly emerging under cover of darkness — the better to avoid threats like hungry songbirds — caterpillars play an enormous but largely unsung role in ecology.

The ranks of caterpillars include scores of spectacular creatures, some seemingly lifted from the works of Dr. Seuss, or Alice in Wonderland. Accompanying this column is a photo of eastern North America’s largest species, the hickory horned devil (Citheronia regalis). It is often likened to a hot dog as a size scale, which is why I placed one in a bun for the photo. The horned devil was released unharmed on a black walnut (a common host plant).

If all goes well for the devil, it will eventually morph into a regal moth, a bat-sized behemoth clad in cinnamon scales punctuated with cream-colored spots. So different are the larva and adult moth that they go by different common names. Such bifurcated nomenclature is not uncommon in the world of moth caterpillars.

Although butterflies are far better known in the Lepidopteran world, it is moths that rule. About 140 species of butterflies have been found in Ohio. Moths crush them in diversity, with at least 2,000 documented species and scores more awaiting discovery. Both butterflies and moths have a four-part life cycle: egg, larva (caterpillar), cocoon (moth) or chrysalis (butterfly), and winged adult.

The caterpillar phase is perhaps the most interesting. Virtually all of our “cats” eat vegetation, and more often than not, a species is tied to a small group of flora, or even one plant. Native plants drive the caterpillar train. Our cats have no co-evolutionary history with nonnative invasive plants and mostly shun them.

Caterpillars are the frontline agents that transform plant tissue into nutritious protein that’s easily assimilated by other animals. They are steaks on legs, preyed upon at epic levels by all manner of predators. In response, moths, especially, engage in carpet-bombing reproduction. Females of some species might lay hundreds of eggs. This is necessary to get some offspring through the predatorial gauntlet and to the reproductive stage.

A highly conspicuous caterpillar consumer group is birds, mostly our songbirds. Without caterpillars to fuel them, many species would quickly vanish. Forests would literally fall silent. The melodies of orioles, tanagers, warblers and others would disappear. Perhaps kings of the caterpillar-eaters are the vireos. Our most common species is the red-eyed vireo, which winters in South America and temporarily occupies eastern North America to exploit the seasonal bounty of caterpillars. About one million red-eyed vireos summer in Ohio, and collectively they eat some 30 million caterpillars daily.

At the recent Mothapalooza sponsored by the Arc of Appalachia, we were fortunate to have the Caterpillar Lab on hand. Founder Sam Jaffe began doing educational programs on caterpillars in 2008, and in 2015 launched the lab, which is based in New Hampshire.

Jaffe and crew enjoy visiting Ohio and have been here numerous times, including several Mothapaloozas. They bring many fascinating specimens and entrance audiences with wee beasts that are all around, but rarely seen. The lab directly contacts about 40,000 people a year, which includes many school visits.

Jaffe and company are pied pipers for caterpillar conservation, and by extension, overall preservation of biodiversity. In addition to educational outreach, the lab does a variety of research, such as the effect of the loss of ash trees on caterpillar species due to the emerald ash borer.

We hope to have the Caterpillar Lab back in Ohio for the next Mothapalooza, which will be July 14-16, 2023, at the Highlands Nature Sanctuary. It’s an event probably quite unlike any other you’ve experienced, and attendees will see legions of interesting moths and caterpillars. Mothapalooza fills quickly, so watch the website for details. Registration will open sometime next spring: https://arcofappalachia.org/Mothapalooza

Naturalist Jim McCormac writes a column for The Dispatch on the first, third and fifth Sundays of the month. He also writes about nature at www.jimmccormac.blogspot.com.

 

Caterpillars, and more caterpillars

I reported on last weekend's great caterpillar safari in my last post, but showed few caterpillar photos. I will atone for that here. Our group found at least four dozen species, and I photographed a fair chunk of them.

Caterpillaring becomes addictive. Taken to extremes, it LOOKS LIKE THIS. I've been at the larval game for some time, and love the thrill of the hunt. Caterpillars do not want to be seen, and the vast majority of species are nocturnal, the better to avoid diurnal songbirds and insect predators. That means the successful hunter must also be active after dark, and that's when most of the subjects of this post were found. Throw in the allure of photography, the challenge of nightime shooting, and the novelty of charismatic subjects that few people photograph, and it's hard to beat.

More importantly, learning about caterpillars helps one learn MUCH more about food webs and ecosystems. Caterpillars are tube steaks on legs; Nature's hotdogs. It seems like everything eats them, and caterpillars are such a huge staple in the diet of many species of birds that we'd lose these songsters without the larvae. Some experts feel that the mortality rate of many caterpillar species is well over 90%. In other words, almost all of them are eaten. Those that make it become butterflies or moths, mate, lay eggs, and carry on the species.

Driving it all is native plants. Our caterpillars are chemically finicky and generally shun nonnative flora, with which they have no real co-evolutionary history. This is yet another reason to plant natives. You'll be growing crops of caterpillars, and feeding the higher-ups on the food chain.

A black-blotched prominent, Schizura leptinoides, rests atop some sort of cocoon, maybe that of a silk moth. I believe the cat's juxtaposition with the cocoon was just coincidence. One thing's for sure, it is a walking dead caterpillar. Those little white cylinders stuck to its upper body are tachinid fly egg cases. The maggots have already hatched, and are eating the caterpillar from within. Death by parasitoid insect is an extremely common fate in this world.

A pair of common buckeye caterpillars, Junonia coenia, nosh on slender foxglove, Agalinis tenuifolia. If they make it, they will morph into one of our most beautiful butterflies. The overwhelming majority of caterpillars are those of moths. Around 2,000 species of moths have thus far been documented in Ohio (some authorities believe MANY others await documentation), while we've only tallied about 140 butterfly species.

The leaf of a sycamore, Platanus occidentalis. An obligate sycamore feeder sits prominently on the leaf. Or perhaps not so prominently. Caterpillars are masters of disguise, or at least many of them are.

A closer view of the caterpillar in the previous photo. It is a drab prominent, Misogada unicolor, which insofar as I know feeds only on sycamore. The pale stripe on its back mimics the pale midribs of sycamore leaves remarkably well. Go look at the previous image. By the way, sometimes the English names of moths are derived from the adult moth, sometimes the caterpillar. There's nothing "drab" about this larva; the name stems from the bland appearance of the moth.

This was a great find, by, I believe, Ann Geise (someone who was there correct me if I'm wrong). It's a hitched arches, Melanchra adjuncta. These caterpillars are often found in fairly conspicuous spots during the day, and that's when this one turned up. It is on water hempweed, Amaranthus tuberculatus, which the cat matches quite well.
 

An amazing bag of goo, this one, and always a crowd-pleaser. A specialist in the extreme, this honey locust moth, Syssphinx bicolor, feeds only on its namesake tree, Gleditsia triacanthos.

One of many oak specialists, this orange-striped oakworm, Anisota senatoria, is feeding on a black oak leaf, Quercus velutina. Oaks support more species of caterpillars than any other floristic group, by a long shot. Their conservation is vital to the ecology of the great eastern deciduous forest.

The slug moth caterpillars are often otherworldly in appearance, often looking like sea slugs plucked from a coral reef. This is a Nason's slug, Natada nasoni. Note the pale vermiculations (squiggles) on its body. Unlike the specialist caterpillars, this one is polyphagous - it eats many species of plants.

Hard to top the exoticness of a purple-crested slug, Adoneta spinuloides. How could you miss this thing, one might think. Like most slug moth cats, it is tiny, maybe a half-inch in length, and quite easy to overlook. We often employ ultra-violet flashlights in our quest. Many caterpillars, including most slugs, glow brightly under such beams.

I was quite pleased to see this species, and this individual was one of at least three found during the weekend. Chris and Sue Zacharias found two on white pine (which is not native in this region), and Randy Lakes found this specimen on native Virginia pine, Pinus virginiana. It's the aptly named pine sphinx, Lapara coniferarum, and it was new for nearly everyone including me.

Thanks to everyone who joined the hunt last weekend! I look forward to the 2020 expedition.

Heavy-duty caterpillaring

A fine group of intellectually curious people convened in Adams County, Ohio over the weekend - our 6th annual get-together, ostensibly to search for caterpillars. And that we do, but as always the foray becomes a natural history free-for-all, and we find lots of other STUFF. Our base camp is John and Tina Howard's Ohio Star Retreat Center. Most of the group stays here, and we all converge on the place to have meals, and photograph temporarily detained caterpillar livestock. It's a great place to stay of you're in Adams County, especially if you are in pursuit of the region's abundant natural history.

The group changes form a bit each year, and we always have one or a few new people, but most of the caterpillar-hunters in this image have been to a few or all of these strange outings. It's a blast, with lots of nocturnal field work. The group is, from back row (L to R): Tom Patt, Sue Zacharias, Chris Zacharias, Ann Geise, Sally Miller, Frances Ganance, Chelsea Gottfried, John Howard, Randy Lakes (peeking over John's right shoulder), and Jason Larson. Front row (L to R): Kyle Bailey, Kim Banks, Colleen Sharkey, Gina Patt, your narrator, Molly Kenney, and Dan Kenney. Not pictured is Judy Ganance, who kindly took the photo. Laura Hughes, Mary Ann Barnett, and Kathy and Ned Keller also joined in for part of the excursion, but weren't there when we took this photo. Sorry if I'm missing anyone else.

I took a boatload of photos, but haven't processed many caterpillar images yet. More of those will hopefully follow, in a future post. This is a saddleback caterpillar, Acharia stimulea, always a crowd-pleaser. Fun to look at, less amusing to the touch. This caterpillar packs a punch, possessing one of the most painful stings of any North American caterpillar.

This is the architecturally ornate larva of the comma butterfly, Polygonia comma. Our official larval scribe, Judy Ganance, recorded nearly 50 species of caterpillars seen by the group.

Now this is a treehopper we can all get behind! It's the keeled treehopper, Entylia carinata, an amazing thorn mimic.

This is a pretty cool little fly, if you ask me. It's a dusky-winged hoverfly, Ocyptamus fuscipennis. The larvae are predators of aphids.

Thanks to Laura Hughes for showing us this amazing spider on Friday night. It is the difoliate orbweaver, Acacesia hamata. This is the only member of the genus north of Mexico - apparently there are five or so species south of the U.S.

The handsomely marked female difoliate orbweaver creates an incredible web. The circular strands of the outer web are incredibly close together and there are a great many of them. Probably 75 strands can be seen in just this snippet of the web, which was much larger.

A jumping spider with a handsome trig, freshly seized. The little eight-legged tough wasn't about to give his cricket up, and squared off with me and my camera.

I would say this one is "cute", as spiders go. It's a bolas spider, Mastophora yeargani. Laura Hughes showed it to our group last Saturday night. She made a great find; this is the first confirmed state record. I think this species was only described in 2003, and its basic life history is not well understood. The spider is resting below a twig and staring at the camera; nearby is her egg case.

More photos and stories from this expedition may follow...

Nature: Seldom-seen caterpillars vital link in food chain

A mammoth hickory horned devil caterpillar/Jim McCormac

Columbus Dispatch

September 16, 2018

NATURE

Jim McCormac

Caterpillars represent the vast underworld of the food chain. Out of sight and out of mind, they make the natural world go ’round.

Trick question: What’s the biggest group of herbivores (by biomass) in Ohio? No, not white-tailed deer. Caterpillars. All our state’s deer would make a big heap. Pile up all of the caterpillars, and that stack would dwarf the deer.

So why don’t you see many, if any, caterpillars? After all, these larvae of butterflies and moths are fantastically diverse, with a collective 2,000-plus species in Ohio.

Short answer: They’re very good at hiding. But caterpillars are prolific and everywhere, especially in wooded areas.

I’ve been stalking caterpillars with a camera for years, and have made thousands of images of them. The vast majority were taken at night. Like a hidden army, caterpillars emerge from hiding spots under cover of darkness, the better to avoid predatory birds, insects and other diurnal predators

Caterpillars have evolved a large, diverse bag of tricks to avoid predators, but literally tons are still found and eaten. Experts think the mortality rate hovers at about 99 percent. Thus, most moths and butterflies engage in carpet-bombing reproduction. One female might lay hundreds or thousands of eggs. Such prolificacy is necessary to get a few through the predatory gauntlet and to the adult-reproductive stage.

The fallen caterpillars did not perish in vain. Birds galore, other insects, and even mammals made meals of them. Caterpillars underpin food webs, and without them we would lose many of our higher animals. The plants that are eaten by caterpillars — which is all of our native species — would go haywire.

Some of these crawling tube steaks are especially impressive, and I recently encountered a Holy Grail. While on a southern Ohio excursion, an exceptionally keen-eyed friend, Molly Kenney, spotted a hickory horned devil 12 feet up in a black-walnut sapling

Our group gathered to marvel at the hotdog-sized behemoth. We eventually extracted the horned devil from its tree for photos. Fierce as it looks, horned devils are harmless. The orange-and-black spines do no damage, nor does it bite.

However, the shock-and-awe factor probably sends most songbirds fleeing.

Eventually, hickory horned devils come to the ground of their own volition and roam about searching for soft earth. This is when people most often encounter them. Once a suitable site is found, the devil will burrow in and form a subterranean pupation chamber in which it spends the winter

Come spring or summer, the adult moth, which is known as a royal walnut moth, will push from the ground. The adult moth is bat-sized, orange-brown and as spectacular as its larva. Unlike its gluttonous caterpillar phase, the moth does not feed, lives but a week or so, and exists only to find a mate and reproduce.

Hickory horned devils are an important part of the ecology of hickory, sweetgum, walnut and a handful of other trees. Most other caterpillars are tightly wedded to a small suite of plants that are indigenous to their area; they will eat nothing else.

Caterpillar production is a huge part of why conservation of native plants is vital — they serve to fuel much of the rest of the food chain. Nearly all caterpillar species shun non-native flora. By planting native species in your yard, you can help generate little sausages for birds and other critters.

Naturalist Jim McCormac writes a column for The Dispatch on the first, third and fifth Sundays of the month. He also writes about nature at www.jimmccormac.blogspot.com.

Head on with the fantastically bizarre hickory horned devil/Jim McCormac

Caterpillar season is upon us!

Well, caterpillar season is really year 'round, but in terms of mature specimens and conspicuousness, late summer and fall are best. I've been afield a lot of late, and have been seeing plenty of the tubular crowd. The following pictorial display is of specimens that I've seen and photographed in the past week, mostly in southern Ohio's Adams and Scioto counties. The variation in caterpillars is mind-blowing, as is their appearances.

FINDING CATERPILLARS: When I share photos such as these on social media, someone(s) will invariably ask how to find caterpillars. Because, for the most part - even though there are probably well over 2,000 species in Ohio - they are out of sight and out of mind. The biggest thing one must do is venture out after dark. Most caterpillars become active under cover of darkness; an evolutionary response to bird predators and various predatory insects that are mostly diurnal, no doubt. During the day, most caterpillars secrete themselves exceptionally well, and are much more difficult to locate. Searching the undersides of leaves should yield results, and a good flashlight is essential. Best of all are UV blacklight flashlights, as many caterpillars glow brightly under such beams. A good knowledge of botany is hugely helpful, as many species are keyed to certain plants. Some plant groups, such as grapes and oaks, are major search sites for caterpillar-hunters, as they often yield fabulous cats. Best of all is getting afield with experienced searchers. I've taken out people who have never caterpillar-hunted many times, and it's always fun to see their reactions as various fantastic bags of goo come to light.

A fabulous leaf-edge mimic, the Checker-fringe Prominent, Schizura ipomoea. They feed on tree species with jagged leaf margins, and the back of the caterpillar matches the shape of the leaf quite convincingly. I see these feeding boldly during the day on occasion; apparently their disguise is so effective that birds often overlook them. The scientific name's specific epithet, ipomoea, is an apparent misnomer. It refers to a genus in the morning-glory family, a group of plants this caterpillar was apparently erroneously recorded as feeding upon, but probably never does.

"... slug caterpillars seem more fantasy than reality." From David Wagner's epic Caterpillars of Eastern North America book (2005). This, by the way, is the book to get should you want to learn more about caterpillars.

This extraordinary beast is a Nason's Slug Moth caterpillar, Natada nasoni. Virtually all of the slugs cats, a few more of which appear below, are exceptional in appearance. The rather distasteful name for these beautiful creatures stems from the caterpillars, and their peculiar gliding mode of locomotion.

A Luna moth caterpillar, Actias luna, appears to glow from within. Unlike the tiny slug cats, this one is a thumb-sized whopper and often stands out from afar under a UV light. We frequently find them on black walnut, but Luna cats will eat a variety of woody plant foliage. The adult moth is one of the most beautiful and widely recognized of our North American moths.

Rather alien in appearance is this Silver-spotted Skipper, Epargyreus clarus, larva. They're most easily found on black locust but feed upon other members of the pea family including hog-peanut, which is what I found this one snacking on.

Another fantastic slug cat, this one the Black-waved Flannel Moth caterpillar, Megalopyge crispata. It resembles a turtle covered in brown shag carpeting, or perhaps Donald Trump's hair. Caterpillars grow through molts, and often look very different at different growth stages. The stages - termed instars - preceding this one look utterly different. The caterpillar above is in its final instar, but earlier ones are white with exceptionally long hairs - like ill-kempt cottonballs. Look, but don't touch - this species is beset with stinging spines capable of delivering painful stings.

A bizarre Camouflaged Looper, Synchlora aerata, feeds upon the flowers of stiff goldenrod. These flower-specialist inchworms adorn their bodies with flower parts of whatever it is that they're eating. Those are goldenrod flower petals projecting from its body. The moth it will become goes by a different name, the Wavy-lined Emerald.

One of our more bizarre larva is the Red-washed Prominent, Oligocentria semirufescens. That's the head at the left, overarched by a strange rhinoceros-like horn. When this beast is eating leaves dappled with browning necrotic tissue, it can blend in amazingly well. I believe it was sharp-eyed Laura Hughes who spotted this one on an Adams County foray, and I'm glad she did - it's only about the third one I've seen.

PHOTO NOTE: I shot this image in the field, as with all the others in this post. The interesting blue background is someone's shirt. The quality - mainly color and blur - of a photo's background is known as the bokeh. Creating an effective bokeh that complements the subject is vital, and the photographer should pay great attention to what's in the background. Bokeh can be artificial, too, by having someone stand behind the subject as in this image, or by holding colored pieces of paper in the backdrop, or leaves or other natural material. Often highly effective are black backgrounds. This look is achieved with flash, and by ensuring there are no objects within five or so feet behind the subject. Then, at least in many situations, the flash causes the background to go black.

This one looks like it came right off a coral reef in a tropical sea. It's the Stinging Rose Caterpillar, Parasa indetermina. Like many caterpillar species, they have boom and bust years, but can be fairly easy to find in seasons of plenty. They'll feed on a wide variety of woody plant foliage.

PHOTO NOTE II: Good general camera settings when shooting caterpillars are f/11 to f/16, ISO 100 to 200, and shutter speed of 1/200. Flash is mostly essential, and flash units that mount atop the camera on the hotshoe will probably always beat the built-in flash. I shoot Canon cameras, and have two types of flashes, both of which excel for caterpillars and other macro subjects. One is the Canon 600 II Speedlite, the other the Canon MT-24EX Twinlite.

Finally, another amazing slug cat, this one the White Flannel Moth caterpillar, Norape ovina. It looks like a jeweler studded the little beast with emeralds. Like the other species in this post, this one is at least fairly common in many areas, and is often easily found during nocturnal searches.

So, if chance permits, get afield under cover of darkness and inspect the leaves. You never know what might come to light!