Another Caterpillar Season

Look closely at nature. Every species is a masterpiece, exquisitely adapted to the particular environment in which it has survived. Who are we to destroy or even diminish biodiversity?

~E.O. Wilson

Yes, it is finally crawling to a close, another season of caterpillar searching, wrangling, and releasing. This one a bit less productive than some perhaps, but rewarding nonetheless. After a couple of caterpillar classes at the Museum and Botanical Garden, we ended with a bang at the Museum’s BugFest event last weekend. It was the usual phenomenal turnout with an estimated 25,000+ attendees. I am never sure how many folks we actually see at out caterpillar booth, but it was a steady stream of curious onlookers for a full 8 hours.

It was so busy this year, that I didn’t take the time to photograph some of our herd of larvae (around 50 different species). As usual, some of the best finds, like the Spun Glass Slug Moth caterpillar mentioned in an earlier post, pupated right before the big event.

spun glass slug close up head on

This strange beauty never made it to BugFest, preferring to pupate about a week before the big event (click photos to enlarge)

We start searching a week or so ahead of BugFest, and we always lose some of our herd  to the many hazards that caterpillars face –  a few larvae erupted with parasitoid wasps or flies, and some we discovered as they were being used as the larval lunch special of the day for some of the many predators out there. With as many hazards as they face, it is sometime amazing we find any caterpillars at all.

Stink bug eating snowberry clearwing larva

While searching for clearwing moth larvae on coral honeysuckle, I came across this scene – a Florida Predatory Stinkbug with its prey

But, butterflies and moths are prolific little critters, and enough survive to keep it all going. I enjoyed watching some egg-laying behavior of several species in the week leading up to our caterpillar classes, including a snowberry clearwing (aka bumblebee moth) laying her eggs on a honeysuckle vine. I collected one egg and photographed the tiny newly hatched larva five days later.

first instar snowerry clearwing

A newly hatched Snowberry Clearwing caterpillar

The show-stoppers this year were two Imperial Moth larvae, one brown in color, the other green. Melissa found both, the brown one when it was a second instar about two weeks before BugFest. She found the green giant the day before, and I wished I could share the looks on the faces of people as they walked along the tables and first laid eyes on that behemoth.

Imperial moth larva eating its shed skin

Imperial moth larva recycling its shed skin

The rest of the critters included a wide range of caterpillars found throughout our region. As I mentioned, I took only a few minutes to quickly photograph some of the larvae before the crowds started arriving and asking questions. Here are a few more of my favorites…

Smartweed caterpillar

The beautiful colors of a Smartweed Caterpillar

blinded sphinx

Early instar of a Blinded Sphinx (we think)

hog sphinx

A Hog Sphinx on wild grape

Though the Imperial Moth larva were crowd favorites, my choice for caterpillar of the day was the weird and wonderful Curve-lined Owlet. These bizarre-looking caterpillars feed on greenbrier and mimic the brown, curled edges of dying leaves (and perhaps the vine tendrils). They often gently wave back and forth, looking like a dead leaving moving in a breeze. When I pointed it out to people, most were stunned that it was a caterpillar, so their camouflage seems to be quite effective.

curved-line owlet

Curve-lined owlet, my choice for caterpillar of the day

The aftermath of all this larval love involves releasing the stars of the show onto their host plants from whence they came. A few that pupated will be housed in proper conditions until they emerge sometime next year, and then they will be released into favorable habitat with the hopes they will create more of their kind. Meanwhile, I may let the macro lens rest for a bit, and see if I can find something a little bigger to ponder while I wander.

Caterpillar Countdown

Beauty can come in strange forms.

~James Dyson

I thought about not saying anything else in this post other than the quote above, because it really does sum up what we found one night this week. Yes, it is that time of year again when we caterpillar-lovers are out and about searching for something cool, something bizarre, something strange and beautiful. Melissa and I both have caterpillar programs today and then next weekend is the annual BugFest celebration at the NC Museum of Natural Sciences, where, once again, we will host a caterpillar booth. So, bear with me as I will no doubt share a few lovely larva images over the next couple of weeks.

We often find our best specimens at night, either by regular flashlight or UV flashlight (many species glow in UV light). And so it was Thursday night…some fine specimens indeed…

Black-blotched Schizura

Black-blotched Schizura (click photos to enlarge)

The Schizura group are some of the leaf edge caterpillars – they chew out a section of leaf and then position their body within that section. The strange protuberances of the caterpillar’s body help disguise it by blending in with the jagged edges of the leaf blade.

Crowned slug

Crowned Slug

One of my favorites, the Crowned Slug, looks like an alien creature. They, like many of the slug caterpillars, are difficult to find because they tend to feed on the undersides of tree leaves (plus, they blend in). These are best located with a UV flashlight.

The highlight of the evening was a species that I have wanted to find for several years. Being a true caterpillar nerd, I have poured over my copy of Wagner’s field guide countless times since it first came out, and been amazed at some of the bizarre larvae that can be found in our area. There are several that were on my “larval bucket list” and it is always a thrill to find one. For this species, I have seen the tiny moth a few times at home and at work, so I knew they were around.

Spun glass slug moth 1, Isochaetes beutenmuelleri

The strange-looking Spun Glass Slug Moth

And this week, I finally found the exquisite larva (with the aid of a UV flashlight).

Spun Glass Slug

Spun Glass Slug

This is the last instar of this translucent little beauty. It was found underneath an oak leaf (various oaks and American beech are the host plants). It is one of the so-called stinging caterpillars (tufts of spines that can inject venom if touched). Apparently, when it gets ready to pupate, the numerous “arms” fall off.

Spun glass slug close up

A closer look

Of course, now I want to find some of the earlier instars. I guess it is good to have goals in your life…

Florence Cats

If you spend your whole life waiting for the storm, you’ll never enjoy the sunshine.

~Morris West

Florence has already had a huge impact on things here in the Piedmont, far away from her predicted point of landfall. While this is minor compared to what people in the more direct path of the storm will have to deal with over the next several days, many schedules in this area have been rearranged and many things canceled or postponed with the storm’s approach. One such cancellation was one of my favorite events of the year, BugFest, at the NC Museum of Natural Sciences. As predictions of the stormy weather grew, it seemed less likely we would need to scour the fields and forests for caterpillars for our annual show of the diversity and beauty of the larvae of butterflies and moths of our region.

But some things are hard to give up. What does a caterpillar-lover do when all the preparations have been made for any wind and water headed our way? Why, you stroll through the yard looking for caterpillars, of course. So, below are a few species discovered this afternoon (and a couple from earlier in the week) while we wait for any impacts from Hurricane Florence.

Monarch larva, last instar

Monarch caterpillar (click photos to enlarge)

Black swalowtail larvae on rue

Two instars of Black Swallowtail larvae – notice how different this species looks in different stages. The larger instar is often mistaken for a monarch due to similar colors and patterns, but note the yellow dots inside the black stripes and the lack of black tentacles on either end compared to a monarch.

Florida fernth larva mo

Florida Fern Moth larva on, what else, a fern

White furcula side view

We love finding “Furkys”. Here is a White Furcula caterpillar on wild cherry

White furcula ventral view

White Furcula, ventral view

Double-lined prominent larva dorsal view

Double-lined Prominent on elm

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A mystery Geometrid moth larva on spicebush…anyone know this one?

Fall webworm

The most common caterpillar in the yard right now, the Fall Webworm, found now on almost any plant

White flannel moth dorsal view

A treat to find a White Flannel Moth larva on redbud, as it has been a few years since I have seen one of these odd beauties..

White flannel moth side view

This clownish looking caterpillar is one of the so-called “stinging caterpillars”, with tufts of urticating spines that can cause a bee-sting-like pain should you touch it.

And a couple from earlier this week at work…

Datana sp. getting ready to molt

Datana sp. larvae just prior to a synchronous molt

Drab prominent larva

A Drab Prominent caterpillar looking anything but…

Stay safe if you are in the path of the storm, but remember to take a moment to enjoy the beauty and wonder that surrounds you.

 

 

Stripes

These caterpillars come in brilliant green, pink and yellow, banded, and striped forms that often look nothing at all like each other.

~MOSI Outside blog post

If you are not a fan of bugs, then you may want to take a break from this blog for a bit because it is what is happening right now (oh, there may be something on bears or birds soon, but bugs rule this time of year). Yesterday at work I got an email and a voice mail from two staff about some cool caterpillars in our lower nursery. Comments ranged from do you know this guy, some sort of sphinx? to as big as a hot dog. Of course, I had to go see.

Banded sphinx larva reddish-green form

Banded sphinx moth (Eumorpha fasciatus) caterpillar (click photos to enlarge)

When I arrived, several staff were working in the nursery and pointed out the “hot dog” larva (it was about the size of my index finger). I recognized it as a banded sphinx. It was the characteristic shape of a sphinx moth larva, but lacked the true rear “horn” of most other hornworms. And the diagonal stripes are oriented in a different direction than those of most other sphinx species larvae (these slope from the abdomen upwards towards the head, whereas those in most species, like tobacco hornworms, go from the abdomen upwards toward the rear). But it soon became apparent that this beauty comes in many stripes…

Banded sphinx larva red form

A nearby banded sphinx with a different dress code

We found several more caterpillars, many with a more reddish color scheme.

Banded sphinx larva green form

And who is this guy?

Then, as I was walking out, I spotted another sphinx on the same host plant (Ludwigia sp.) but with a totally different pattern. I assumed it was a different species, but when I checked my field guide, I discovered that banded sphinx larvae come in two forms – a heavily striped one and a green one.

A close-up comparison of the three major color morphs of this species we found yesterday is shown above. Amazing variety for one species! And they are beautiful from every angle.

Banded sphinx larva reddish-green form dorsal view

Looking good from above…

Banded sphinx larva reddish-green form ventral view

…and below

Banded sphinx larva reddish-green form ventral view close up

You gotta love those “socks”

If you think these caterpillars are amazing, here is a look at the adult banded sphinx moth…

Banded sphinx moth

Adult banded sphinx moth

This moth was sitting at the front door of the Allen Education Center one morning earlier this summer. I took it out of harm’s way and snapped a couple of photos before releasing it. Perhaps some of those amazing caterpillars are descendants of this individual. Discovering several of these stunning caterpillars is one reason I find it so interesting working at the NC Botanical Garden. The diversity of native plant species makes for an incredible richness of fauna as well. Every day, a new discovery!

Caterpillar Clusters

Groups tend to be more extreme than individuals.

~Daniel Kahneman

In spite of the heat and humidity (or maybe because of it), this is one of my favorite times of year – caterpillar time. The period between mid-August and mid-September tends to be the best time to find the greatest variety of interesting caterpillars in this part of the world. Most species are nearing the end of their larval life and are getting larger, the amazing parasitoids and predators are reaching a peak, and many of the caterpillars are getting ready to pupate, which usually means they will be on the go looking for a suitable spot making them more likely to be encountered out in the open.

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Caterpillars clustered on an oak leaf (click photos to enlarge)

This past week I had a few nice encounters with a bizarre behavior – caterpillar aggregations (or clusters). The first was a group of Datana sp. (they can be tough to tell apart) larvae clustered on the back of an oak leaf in front of one of our buildings at work. Garden staff had alerted me to them so I walked over and grabbed a couple of quick pics in between what has been constant rain these past two weeks.

_-2

Aggregation of walnut caterpillars on tree trunk

The next day, I checked on the oak leaf, and the cluster was still there, huddled together. I wasn’t sure whether it was the weather, or perhaps an impending molt, causing this behavior. When I got back to my office, another coworker texted me a photo of what looked like a blob of caterpillars on a tree trunk next to her car. This one was a bit more dramatic (as she said, it looked like a squirrel had been squashed on the side of the tree). This group looked like walnut caterpillars, Datana integerrima. They are hairier than the other species from earlier in the day, and this species feeds only on trees in the Juglandaceae family (black walnut, hickories, pecans, and butternut).

_-3

The pile of larvae was huge and several caterpillars thick

This species is known to form large aggregations, often 2 or 3 caterpillars deep, on tree trunks (this larval pile was about 12 inches long and wrapped about 5 inches around the hickory trunk). It turns out this is a phenomenon called synchronous molting, and is fairly common in several species of Datana larvae. I looked online for information on how they manage to coordinate the timing of their molt, but was unable to find a definitive answer. I assume they are able to communicate with pheromones which may impact hormone levels that trigger the molt.

_-4

A close-up view of the hairy mass

This process may take a couple of days before they finally shed and head back up into the tree to continue feeding. But why do these caterpillars cluster? Looking through several resources it seems there are a few theories: thermoregulation (clustering together increases body temperatures of the individuals); feeding advantages (feeding together in groups may help overwhelm plant defenses); and the most likely, anti-predator/parasitoid defense. Datana larvae typically display a defensive U-shape, raising the tip of the abdomen and arching the head and thorax back. They exude what is presumably distasteful liquid if the threat continues. They also exhibit synchronized head-flicking in response to an approaching flying predator or parasitoid. The time just before and after a molt is a very vulnerable one for caterpillars, so it makes some sense to aggregate and combine defenses, although it may also make them more vulnerable to being discovered by certain caterpillar-seekers like hungry birds or curious humans.

Walnut caterpillar sheds

Shed skins of walnut caterpillar cluster (compare to second photo above)

After work that day, I decided to go back out to the walnut caterpillar cluster for a few more photos. As I approached, I could see something was different. The cluster was not as noticeable as I approached their tree. They had all shed! The cluster now looked like a week-old squirrel carcass stuck to the tree, and almost all of the caterpillars were gone, presumably up in the canopy feeding. What a difference a few hours made. As I looked at the pile of shed skins, a slight movement caught my eye a few inches away from the heap of husks…a line of small caterpillars clinging to a green briar (Smilax sp.) vine,

Turbulent Phosphila early instars

Early instar turbulent phosphilas on Smilax sp.

These little guys are turbulent phosphilas, a favorite of mine, both for their odd name and their strange color patterns. I am more familiar with their latter instar where they are adorned in bold black and white stripes and more prominent fake eye spots that make it hard to discern which end is which. Learn more about them in an earlier blog post. I am glad to find these small larvae. Maybe a few will make it until BugFest (coming up September 15!).

I walked over to the other caterpillar cluster on the oak. They had also molted after at least two days of hanging out on that one leaf.

Datana on oak just after shedding wide view

Newly molted Datana sp. larvae on oak leaf (compare to first photo above)

I am still not quite sure which species of Datana these are…most likely either Contracted Datanas, D. contracta, or Yellow-necked caterpillars, D. ministra.

Datana on oak just after shedding side view

Arched defensive posture of Datana larvae

As I maneuvered the branch for a better photo, the cluster began to twitch and assumed the defensive U-posture common to this genus. Teamwork against a perceived threat.

Datana on oak just after shedding

Cozy caterpillars

Though they looked content all gathered together, I assume they eventually dispersed back up into the leafy regions of the tree. I am thankful to work in a place with such biodiversity and that these larval congregations were all in places so accessible that they allowed me to share a few moments of wonder with them.

A Fondness for Caterpillars

And what’s a butterfly? At best, He’s but a caterpillar, drest.

~John Grey

Another season of caterpillar finds and larval programs is winding down. We have been searching high and low for larvae and, consequently, caring for a menagerie of crawling critters for several weeks now. My caterpillar programs have ended, and Melissa’s will be finished later this week. Our charges have been oohed and aahed over by hundreds of wide-eyed learners at a series of events at the North Carolina Botanical Garden, the museum’s BugFest, and a well-attended (and well-run) Master Gardener’s conference in Greensboro. These little guys have really earned their keep this past month. Many have pupated in preparation for their long winter’s nap, others have been (or will be) released back into the wild, and, sadly, many have succumbed to a variety of parasitoid wasps. It is somewhat shocking how many caterpillars meet this fate, but I suppose it is one of the main reasons we are all not knee-deep in frass (caterpillar poop) by the end of the summer.

So, this post is to say thank you to all the marvelous Lepidoptera larvae that have graced us with their beauty and fascinating behaviors these past few weeks. Their variety of “attire” and striking forms are just one of the reasons that I have developed such a fondness for caterpillars over the years. Here are a few of the stars of this caterpillar season…

Hog sphinx green

Hog sphinx on wild grape (click photos to enlarge)

Hog sphinx 1

Same hog sphinx, later instar

Waved sphinx?

Waved sphinx on ash

Rustic sphinx

Rustic sphinx on beautyberry

pawpaw sphinx

Pawpaw sphinx deciduous holly

Hummingbird sphinx larva

Hummingbird clearwing on possum haw

Four-horned sphinx

Four-horned sphinx on river birch

Yellow-haired dagger

Yellow-haired dagger, early instar

Hoary alder dagger

Hoary alder dagger moth on tag alder

Retarded dagger moth

Bantam maple dagger on maple

Salt marsh caterpillar?

Salt marsh caterpillar

unid parasitoid pupal mass from salt martsh caterpillar

Strange, communal pupal case of parasitoid wasps that emerged from the salt march caterpillar

Black-etched prominent whipping tails

Black-etched prominent “whipping its tails” as a defense

unid early instar prominent

Mottled prominent, early instar, on oak

White-barred emerald

White-barred emerald, a wonderful twig mimic, on oak

Purplish brown looper larva - twig mimicg

Purplish-brown looper, a huge twig mimic with a head capsule that resembles a leaf bud, on sweetgum

Imperial green

Imperial moth on sourwood

Smaller parasa

Wavy-lined heterocampa just after a molt (you can see the thoracic antlers of the early instar on the shed skin), on wax myrtle

Stinging Rose Caterpillar and shed skin

Stinging rose caterpillar about to eat its shed skin (I accidentally touched this guy at BugFest and felt a mild bee sting sensation for about 45 minutes), on persimmon

Puss Moth caterpillar shedding its skin

Puss moth caterpillar shedding its skin (note color change), on wild cherry

Spiny oak slug

Spiny oak slug on witch hazel

Smaller parasa 1

Smaller parasa on ironwood

Nason's slug

Nason’s slug on oak

Io moth caterpillar

Io moth on hickory

Black-waved flannel moth early instar

Black-waved flannel moth, early instar

Black-waved flannel moth later instar

Same black-waved flannel moth, later instar

Skiff moth larva on cherry

Skiff moth, last instar, on wild cherry

Skiff moth larva approaching pupation

Same skiff moth, getting ready to pupate

Viceroy chrysalis

Viceroy butterfly chrysalis

Monarch chrysalis

Monarch butterfly chrysalis

 

 

 

 

 

 

BugFest Residue, Part 2

Nature, in her blind search for life, has filled every possible cranny of the earth with some sort of fantastic creature.

~Joseph Wood Krutch

Here are a few more of the fantastical critters from our scouring of the woods and fields for BugFest…

Polyphemus moth caterpillar

Polyphemus moth caterpillar (click photos to enlarge)

The stars of this year’s caterpillar table were several huge polyphemus moth larvae. We found them on oak, river birch, and red maple this year, and found several on trees at a Chatham County wholesale native plant nursery, Mellow Marsh Farm.

Polyphemus moth caterpillar head shot

These large larvae are eating machines

I was happy that only one of these eating machines began to pupate before the big day, since it is always a treat to share some of our larger species with the crowds.

Smartweed caterpilar

Smartweed caterpillar

One of the more striking species we usually find is the smartweed caterpillar. And this year, we actually found it on smartweed (although I think it crawled off to something else when I took this photo), instead of the usual cattail.

Snowberry clearwing freshly shed

Snowberry clearwing

We borrowed a coral honeysuckle plant from a nearby native plant nursery, Cure Nursery, because it was loaded with feeding snowberry clearwing larvae (these become bumblebee mimic day-flying moths). I caught this one right after it shed (you can see the head capsule just under its legs, and the old tail spike lying with the whitish shed skin behind the caterpillar).

Nason's slug underside

Underside of Nason’s slug caterpillar

The slug caterpillar group is one of my favorites because of their bizarre shapes and colors. We had a Nason’s slug in a petri dish and it obliged by sitting upside down all day so people could see why it is called a slug caterpillar (they lack paired abdominal prolegs that other caterpillars have; they glide rather than crawl).

Crowned slug

Crowned slug

One of the more fantastical of the group, the crowned slug, is ringed by what look like feathered tentacles armed with stinging spines. These are always a treat to find and share.

Spiny oak slug

Spiny oak slug

One of the most striking in terms of color from this year was this spiny oak slug. It is a species that can be quite variable in color, but all are beautiful.

Smaller parasa 1

Smaller parasa

My favorite find was one that didn’t last long enough for other people to enjoy it (it pupated the morning of BugFest). But, to be honest, it probably meant more to me than it would have to a lot of other people. Melissa spotted this (somehow) above our heads on a back lit leaf. When we pulled the branch down to see if it was even a caterpillar she had seen, I knew immediately what it was. I had seen it in the field guide a couple of years ago and had wanted to find one ever since (yup, I am a caterpillar nerd for sure).

Smaller Parasa 1

Smaller parasa moth from two years ago

That page in the book caught my attention when a small beautiful moth came to my window one night a couple of years ago. The gorgeous green helped me identify it as a smaller parasa moth. But when I saw the caterpillar, I really wanted to find one. Well, two years later…

Smaller parasa

What a cool caterpillar!

Good things really do come to those who wait.

What a Way to Go

Nature is so much worse than science fiction.

~Quote attributed to a student in an introductory entomology course

We discovered a small caterpillar last week that was adorned with some unusual accessories, and that usually isn’t a good thing if you are a caterpillar. I think it was either a variable oakleaf, or a double-lined prominent caterpillar. Both are common species that feed on a wide variety of trees and shrubs.

Variable oakleaf caterpillar with parasites

Caterpillar adorned with green accessories (click photos to enlarge)

I have seen these bright green baubles attached to a few other caterpillars over the years, and it never ends up well.

Variable oakleaf caterpillar with parasites close up

Not the type of fashion accessory you want if you are a caterpillar

They really are beautiful in shape and color when you take a closer look. The first time I saw a caterpillar with these green blobs on its side was a few years ago. I thought they might be some sort of strange cocoon of a parasitic wasp. I was close…they are actually the larvae of a tiny parasitoid wasp in the family Eulophidae.

eulophid-wasp-pupae

Eulophid wasp pupae next to the dead host caterpillar

After watching the caterpillar for a few days, I came back to find a strange array of tiny black blobs near the shriveled caterpillar carcass.

eulophid-wasp-pupae-1

The small piles of yellow “stones” near the pupae are actually waste products

When I looked at my macro images, the small black blobs looked like some sort of macabre lawn recliner, with a tiny pile of rocks at the base. The black blobs turned out to be wasp pupae lying on their backs, and the piles of rocks are the waste products excreted by the wasp larvae prior to pupating. These are parasitoid wasps in the genus Eulophis. They feed inside their caterpillar host, mature, and then pupate in a group near the carcass of their victim. The excellent reference by Eiseman and Charney, Tracks and Signs of Insects and Other Invertebrates, refers to these bizarre creatures as “tombstone pupae”.  I find a lot of these clusters of Eulophis pupae on the undersides of sycamore leaves this time of year.

Caterpillar with Euplectrus pupae

Another strange way to go

A few days ago I found another caterpillar that had met what seemed like an unusual death.

Caterpillar with Euplectrus pupae 1

At first, I thought a fungus had attacked this caterpillar

The fuzzy texture initially caused me to think some sort of fungus had killed it.

Euplectrus wasp pupae

And what are these tiny black pellets?

But when I knelt down and took a closer look, I could see what looked like pupae inside the fuzz, as well as some tiny black pellets or balls stuck to the threads. What the heck is this? Going back to my reference book (mentioned above) for all things strange in the invertebrate world, I found a plausible answer. This caterpillar had been killed by another type of parasitoid wasp in that same family, but most likely in a different genus, Euplectrus. These larvae tend to form a cluster on the dorsal surface of the living caterpillar. When they finish feeding, they move to the underside of their deflated host, and arrange themselves in a row, and prepare to pupate. They create a gauzy, web-like cocoon, which attaches the caterpillar remains to the plant and provides a protective covering. The black pellets are the meconium, or waste products, cast out by the prepupa. It looks as though there wasn’t quite enough room under the carcass for all the wasp larvae to pupate, so some had to be elsewhere in the fuzzy covering.

How bizarre…and it is all happening just outside my door!

 

 

In an Instant

Nature taking its course – hunter and prey, the endless circle of life and death.

~Stephanie Meyer

Melissa found some cool caterpillars on a Viburnum this weekend while we were walking in a city park in Richmond.

hummingbird clearwing larva

Hummingbird clearwing caterpillar on Viburnum sp. (click photos to enlarge)

I walked over to take a look and saw a beautiful hummingbird clearwing larva, Hemaris thysbe, in the classic defensive pose of most sphinx moth caterpillars – front of body reared up, head tucked in, body aligned along the twig or mid-vein of a leaf. Suddenly, a huge European hornet, Vespa crabro, appeared and went straight for another caterpillar on the shrub, another hummingbird clearwing.

European hornet attacking caterpillar

European hornet attacking a caterpillar

I managed two quick pictures, and the hornet flew off, carrying its prize back to its nest, where the defeated caterpillar was sure to be chewed up and fed to some hungry wasp larvae. We just stood there, amazed at what we had witnessed. When I looked at the image the next day, I noticed there was another, smaller caterpillar on the same leaf (look just to the left of the clearwing’s “horn” and you can see another small, green caterpillar).

European hornets first appeared in the United States in the mid-1800’s and have since spread throughout most of the East. They look like a very large (up to 1.5 inches) yellow jacket, but are more brownish yellow in overall appearance. We didn’t have time to stick around, but I would not be surprised if that same hornet didn’t come back and search that shrub again, perhaps finding one or more other victims to carry back to the nest. Amazing how a scene in nature can change in an instant.

Leading a Double Life on the Edge

There is more both of beauty and of raison d’etre in the works of nature- than in those of art.

~Aristotle (384 BC-322 BC)

The adaptations of insects in our yard are both beautiful and incredible. Here is a little more on some leaf edge caterpillars discovered the past few days…

Double-toothed prominent

Double-toothed prominent on elm leaf (click photos to enlarge)

One of the most exciting finds was a group of double-toothed prominent caterpillars (Nerice bidentata) on an elm sapling. These guys are amazing in that they have noticeable fleshy “teeth” on their dorsum that mimic the double serrated leaf edge of elm leaves, their host plant.

Double-toothed prominent early instar 1

Early instar of double-toothed prominent larva

Several of them molted over the past few days and I noticed what seems like a slight change in behavior between the different sizes. The smaller larvae are somewhat darker in color and seem to feed along the leaf edges in a more exposed position.

Double-toothed prominent on small leaf

Their color and pattern aids in the deception

The brown tips of the prolegs match brown spots along the mid-vein of the leaf.

Double-toothed prominent close up

Later instar

Larger larvae appear lighter in color, and seem to feed at an angle that puts them slightly under the leaf. The leaf underside is lighter in color than the top, so maybe this is why. The larvae also have angled stripes along their sides which mimic the venation of the leaves, adding to their effective disguise.

Double-lined prominent

Double-lined prominent on elm leaf

While looking at other elm saplings, I came across another species that seems to mimic both the leaf edge and the twigs of its host plant. When viewing the dorsal surface of a double-lined prominent (Lochmaeus bileneata), the reddish-brown color resembles an elm twig.

Double-lined prominent 1

The light stripes may mimic the leaf petiole

When viewed from the side, the white and yellow stripes along the cater[pillar’s body look like the mid-vein of a leaf, and the brown resembles dying leaf tissue.

Double-lined prominent 2

Even the head stripe helps in the disguise

The feeding position (head towards the tip of the leaf, body along the mid-vein) reinforces the effectiveness of the cryptic pattern and colors, with even the stripes on the head capsule resembling part of the angled leaf venation. I suppose it should come as no surprise that I can spend hours wandering around the yard, amazed by the small wonders all around me. I hope you all can spend some time outside this holiday weekend and discover wonders of your own.