Major Moth Night

 

As always, click the image to enlarge

A group of us enjoyed a superb night of mothing last night at Beth Crane's property in Hocking County. Thanks to Beth and Richard McKee for hosting everyone, and for their excellent hospitality. We were fortunate to have Laura Hughes, John Howard, and Kelly Capuzzi join us - all are superb naturalists and accomplished moth-ers. We had three light setups going and that worked like a charm.

John Howard created this artful display of some heavy hitters that visited our sheets. They are Ash Sphinx, Elm Sphinx, Virginia Creeper Sphinx, Pandorus Sphinx, Imperial Moth, Regal Moth (2), Tuliptree Silkmoth, and Rosy Maple Moth. This was just a fraction of the moths that we saw. There were over 20 Imperial Moths, 6-8 Regal Moths, many sphinxes of various species, and scores of other interesting moths. We finally left at 2 am, and things were still going strong.

These sorts of moth numbers and diversity speaks to a very healthy local ecosystem full of native plant diversity, and largely free of light pollution and other deleterious factors that cause moth declines.

An interesting distant view of one of the mothing stations, John Howard's professional setup. Thanks to Shauna Weyrauch for this image and the next one.

A closer view of one of the setups. Black lights and mercury vapor or other powerful lights lure the moths, and most end up on the white sheets where it is easy to observe and catalog them. Sometime before dawn, the lights are extinguished and the moths shooed away back into the wilds.

Head on with a Regal Moth. This is one of Ohio's largest moths, and they are so large that one has a noticeable heft to it when handled. This moth is densely fuzzy and looks like a stuffed animal. As befits such a large lepidopteran, its caterpillar is also gargantuan and is called a Hickory Horned Devil. See the photo below for an image of one of those hotdog-sized beasts.

Hickory Horned Devils are often likened to a hotdog, as a size comparison. It isn't an exaggeration.

I'm still sorting through my imagery but have lots of good stuff. Including a few rather enigmatic species, and a few that only be described as cute. I'll post up some of those later.

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.

 

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

Hickory Horned Devil

I braved the 90+ heat and humidity, and bushwhacked for about three miles through some of my favorite hidden spots today. A primary objective was spending some quality time with my Nikon D7000, which I am still very much learning. So, as I slogged through fens and woodlands, I was especially on the lookout for tiny stuff, as I really wanted to use the 105mm macro. I found lots of suitable subjects, and more on some of those later. But, the following beast was a huge bonus and a macro lens was scarcely necessary!

One of the spots I visited has a grassy parking area, and I wheeled the VW into the shade cast by a handy bitternut hickory. I'm always on the watch for caterpillars, especially the one that follows, so before leaving the car I gave the hickory's foliage a good once-over. Bingo! I think this was Mother Nature's reward for me, for working with the Columbus Dispatch to develop a story that appeared in today's paper on the importance of caterpillars. READ IT HERE.

A dead twig where it didn't look like a dead twig should be. A closer glance revealed movement. My lucky day - a hickory horned devil! This enormous caterpillar is sort of the Holy Grail for caterpillar-seekers, with good reason. They are spectacular.

I backed the car off a few feet, jumped out and started hauling out the camera gear. Even after setting my tripod a few feet away, the devil paid no mind - it just continued slowly browsing the hickory foliage. This monstrosity was probably four inches in length, and is due to get even bigger. I'd say it's in its next to final instar. Horned devils become green in their last larval stage. I was sorely tempted to take it back home with some hickory foliage, and see if I could raise the animal to adulthood. But these sorts of things are better left alone unless you've got some really justifiable reason for collecting.

At one point, I reached in to adjust a leaf, and that movement caught the caterpillar's attention. It lunged that ferocious looking horned head in my direction with great rapidity, and splayed its horns for full effect. Hickory horned devils are harmless, of course, but if you didn't know what it was, this menacing display would probably cause you to back off. If the caterpillar is threatened by a potential predator such as a songbird or perhaps parasitoid flies or wasps, this act might be enough to save it. Interestingly, a Yellow-billed Cuckoo was calling intermittently close at hand as I made these photos. Cuckoos are MAJOR caterpillar hunters, and that bird probably would have loved this thing.

The tubular glutton still has a piece of hickory leaf in its jaws. Note also the curious handlike "feet" capping the prolegs. Caterpillars are eating machines, and a big hickory horned devil can tear through some serious foliage. As greenery is mowed down and sucked into the front end, the inedible remnants are constantly expelled out the back end. Hickory horned devil frass - poop - pellets can be a centimeter in length. The first one of these that I ever saw was because of its frass. The person I was with with spotted a pile of fresh frass, looked up into the tree, and there was the devil chomping away.

The caterpillar was copiously beset with small branched spines. I think that most or all of these are shed when it molts into the final instar.

Those are some big, powerful legs and the horned devil uses them to tightly clasp twigs. It'd probably have been some work to pry it off there, but such grasping power comes in handy during storms and the attendant threat of being blown from the tree.

If all goes well and this hickory horned devil makes it to adulthood, this is what it will become. A royal walnut moth, Citheronia regalis. That's a suitably apropos scientific epithet, as both the caterpillar and the moth are certainly regal.

Hickory Horned Devil

I promise to lay low on the caterpillar/moth/butterfly stuff for a while, but the following pics and story is just too cool not to share.

Thanks to David Hughes and Laura Stalder for discovering this amazing creature, taking pains to help ensure its survival, and sharing their photos with us.

The incredible Hickory Horned Devil, probably the most spectacular caterpillar in the eastern United States. These things are mammoth; the size of a hotdog. While they look fearsome and dangerous, Hickory Horned Devils are all bark and no bite. Those intimidating horns don't inject poison, the thing can't bite, and if you can overcome the fear factor, they're easy and safe to handle.

Hickory Horned Devils spend their time high in trees, vaccuuming up foliage like an over-active paper shredder. Thus, they're hard to spot, and I've only seen one. I was with a moth expert, and he actually spotted the devil's frass, or droppings, on the ground and then looked up and saw the cat up in the tree.

While David and Laura watched the devil happily chowing on walnut leaves, other creatures with much more malicious intent were also watching. Here, a tachinid fly moves in to investigate the caterpillar. There are scores of species of tachinids, and some look much like house flies, as this one does. But they've all got long stiff bristles, on their abdomen, which give them a distinctive appearance.

If you are a caterpillar, you don't want to be stalked by one of these flies. Even though the horned devil outmasses this little fly by a factor of 100 or more, the tiny tachinid spells doom. If you want to see the ultimate result of a tachinid's handiwork, GO HERE.

As David and Laura watched, the tachinid fly extended a long ovipositor (an appendage for laying eggs) and began sticking small, gluey eggs to the Hickory Horned Devil. Her spawn is visible in the above photo: six little white dots. Left to their own devices, those eggs would quickly hatch and the miniscule fly larvae would promptly burrow into the caterpillar's tissue. Once inside, they would commence eating it alive, cleverly avoiding the most vital of tissues, thus keeping their victim alive for as long as possible. Eventually, like a scene from a sci-fi horror flick, the now much larger fly grubs would burst from the body, leaving behind little more than a hollowed out husk.

This is the world's luckiest Hickory Horned Devil. Dave and Laura knew what was going on, and fetched a pair of tweezers. With the precision of a skilled surgeon, they carefully plucked the eggs of death from the devil's body, and hopefully it'll survive to pupate and become one of our flashiest moths.

Hickory Horned Devils grow up to become one of these, a Royal Walnut Moth, Citheronia regalis. I took this shot a few years back at the amazing McMoth's in West Jefferson, Ohio. Royal Walnut Moths are just about as impressive as their caterpillar - massive hand-sized things with a furry body the size of a roll of nickels.

Thanks to David and Laura, not only for sharing their amazing photos with us, but also for their caterpillar rescue operation that will hopefully result in another much-needed Royal Walnut Moth.