It provides strength to the armor plate of the beetle, keenness to the lancet of the mosquito, endurance to the rasping fiddle and bow of the cricket and the katydid.
~Edwin Way Teale, on the properties of chitin
Late summer and early fall are a time of abundance of many types of invertebrates in our woods. Many are reaching their maximum size and activity levels in preparation for however they spend the winter (most as eggs or pupae).
A species of katydid out in the yard (click photos to enlarge)
Last week, I noticed a particularly large katydid on a shrub in the front yard. The songs of katydids reverberate through the treetops here most of the summer, but the onset of cooler weather has quieted them somewhat. They make their sounds by stridulation – rubbing one body part against another. In the case of katydids, they rub the base of the front edge of one forewing against a bumpy ridge at the base of the opposite wing.
Eardrum on front leg of katydid
Other katydids hear these sounds by means of oval-shaped tympana, or eardrums, located on each front leg.
Katydid from above
There are several species of katydids in our area and I have not yet learned how to accurately identify most. I think this one may be one of the Angle-wing species, perhaps the Greater Angle-wing Katydid, Microcentrum rhombifolium, but I can’t swear by it. Looking from above, I can see why this group might be called Angle-wings.
Katydid wings are great leaf mimics
And it is the wings that draw your attention to these beautiful insects once you are lucky enough to find them. The wings help make these katydids excellent leaf mimics, which comes in handy when you spend most of your time feeding on tree leaves.
Detail of katydid wing showing venation
The closer you look, the more amazing the detail becomes. While looking for caterpillars this time of year, I have been surprised on many occasions to suddenly come face to face with a pair of katydid eyes staring back at me when I grab a tree branch. This disguise can be quite effective, an important trait when you represent a large tasty meal to many other forest-dwellers from birds to mice to predatory insects and spiders. But, blending in isn’t always effective, especially when you take flight, or simply fall from your feeding perch.
Katydid caught in spider web outside my window
This is especially true around houses, where katydids are often attracted to lights at night. And, unfortunately for them and many other night-flying species (and the unwary person exiting a doorway), a variety of spiders also seem to like the windows and doors of woodland houses as sites for their large sticky webs. One night last week, a large katydid was entangled in the web of an orb weaver spider just outside the kitchen door. Too bad for her that KatyDid what she did in this case.
The grace and elegance of every adult butterfly and moth, as it flits about on wings radiant with color, are counterbalanced by the grossness and ugliness of the immature insect.
~Edwin Way Teale
As you probably know, if you are a reader of this blog, I don’t agree with this somewhat surprising view held by the great naturalist, Edwin Way Teale. Perhaps he was simply remarking on the belief held by many in the general population that caterpillars are nasty, ugly worms, that do nothing but damage our plants. In contrast, I find caterpillars to be one of the most fascinating groups of critters we have around us – so diverse, beautiful, and bizarre. And, people are fascinated by them, once they get to know them. That was proven once again this past weekend at the NC Museum of Natural Sciences’ annual BugFest event. Total attendance at this year’s BugFest was estimated at over 31,000 visitors, and I feel like those of us in the Caterpillar booth may have talked to most of them.
This Imperial Moth caterpillar was the largest larva at our booth this year at BugFest (click photos to enlarge)
It was a tough year for finding many of the larger caterpillars that are often the show-stoppers, although we did manage one nice Imperial Moth, Eacles imperialis, that managed to stay a caterpillar until the day after BugFest.
Puss Moth larva
But it was a very good year for some of the more unusual caterpillars. One of them, the Puss Moth Caterpillar, Megalopyge opercularis, is almost as fascinating to people as the larger, showier species. This small fuzz ball goes by many other names – the Possum Bug, Woolly Slug, Perrito (Spanish, for little dog), and Asp (the latter is the better-known common name in Texas). The adult moth is known as the Southern Flannel Moth (see images on the Moth Photographers Group web site).
Late instar of a Puss Caterpillar from last year’s BugFest
Last year we were lucky enough to find one Puss Moth larva. It was an earlier instar, and was somewhat orange in color, giving it a strong resemblance (some would say) to a certain political figure’s noticeable hair-do. This year, we found tree of the larvae, feeding on Wild Cherry and an Oak. Oaks are generally the preferred host, but they are found on a variety of other tree species.
Last instar of Puss Moth caterpillar
The larvae this year were all last instar larvae, being a darker gray-brown and having the noticeable white curly tufts on each side. These critters don’t look much like a caterpillar. They are covered in fur-like setae and appear to have a tail in later instars.
Puss Moth Caterpillar underside
And, unlike most caterpillars, they have two sets of accessory abdominal prolegs. Their head capsules are generally hidden by the “fur” and they appear to more or less glide over leaf surfaces when they move, but are not members of the Slug Caterpillars, Family Limacodidae.
Close up of larva showing spines underneath
But, like many in that family, these cute little fluffs of fur can also inflict a painful “sting” from urticating spines hidden beneath their fuzzy appearance. They have bumps along their body armed with hollow spines with a venom gland that inject a toxin into anything that touches them. All stages of the larvae are armed, but the toxicity (and pain) increases with increasing size of the larvae. This species is considered the most venomous caterpillar in the United States and has been responsible for many painful visits to a hospital, especially in Texas, where the species is much more common. A research paper describing the symptoms of the painful encounters with this species chronicles burning pain, nausea, swelling, and itching. During programs, we house our specimens in clear plastic containers for safe visibility, and are careful when adding new food. Most people will probably never see one of these unusual larvae since they both feed and pupate in trees. And, even though this species can be painful, the vast majority of caterpillars are harmless to humans.
Puss Moth cocoon under construction (note the front of the larva visible on the right – white and holding onto twig with a pair of legs)
On Saturday, one of the visitors saw something moving on one of the larvae and asked what it was. I looked and could see something just under the skin going back and forth. My first thought was some sort of parasite that was about ready to erupt. I did notice some silk strands attaching the larva to a twig, but reasoned that maybe the parasite had hijacked the larva’s behavior. As the afternoon wore on, it became apparent it was not a parasite, but rather the larva constructing its cocoon and incorporating that furry exterior into the project.
Puss Moth cocoon day 1
By the end of the day, the developing cocoon looked like an elongate, silk-covered version of what I have found on twigs in the past (see below). Some of the venomous spines are supposedly incorporated into this outer covering, although the larva retains most of them on its body. An excellent summary of the life history of this species with amazing images can be found on the University of Florida’s Featured Creatures web site.
Puss Moth cocoon day 3
By Monday, the cocoon construction had progressed and the shape was beginning to look more familiar.
Puss Moth cocoon day 4
The next day, the distinctive dorsal hump (packed with the soft hairs from the caterpillar’s body) was visible. I could also see the operculum on one end that gives this fascinating creature its species name, opercularis (right side in image, before the long taper of silk). There are probably two generations per year with this one overwintering as a larva inside the cocoon and then pupating in the spring.
A weathered cocoon reminds me of a mini-mailbox, complete with a door (partially opened on right)
The Featured Creatures page mentioned another peculiar aspect of the life history of this unusual species – it has a pre-adult phase called a pharate adult. This is the phase that pushes open the operculum when the moth is ready to emerge. After the pharate adult gets the “mailbox door” open, the adult moth will then emerge from the pupal skin and fly off. Bizarre indeed.
Parasitic wasp larva on orbweaver spider (click photos to enlarge)
A friend had spotted an odd-looking spider that had spun a web on her car. Closer inspection revealed the spider had a hitch-hiker, a parasitic wasp larva. I watched the spider over the next few days until one morning, it was no longer in a web, but was lying on the ground, shriveled and dead.
Wasp larva spinning cocoon, suspended in a special web made by its spider victimCompleted cocoon
The wasp larva was now much larger and was constructing a cocoon in a small sturdy web that had been made by the spider before its demise. I found references online where scientists speculated that the parasite somehow managed to coerce the spider into making an alternate style web before it was totally drained by the feeding larva.
Studies reveal the wasp larva hijacks the behavior of the spider
A recent study published in the Journal of Experimental Biology (and reported in the New York Times a little over a week ago) now reveals that these wasp larvae (or at least similar species to the ones I photographed) incapacitate their hapless victims by taking control of their nervous systems and turning them into zombies. How cool is that? The spider’s final act is to construct a small, tough web that helps support and protect the cocoon spun by the wasp larva as it readies itself to pupate. The researchers found that this last web made by the hapless spider was similar to one they make as a resting or molting site web. In other words, this design is something already in their web-building repertoire, but the wasp larva hijacks that genetically programmed behavior for its own purpose before killing the spider. They also found this last cocoon web was a beefed-up version of the resting web usually made by the spider, which means it probably offers even more protection for the master wasp larva. The scientists suspect the spider’s behavior is triggered by a substance similar to the spider’s molting hormone injected into the spider by the larva. Zombies…fact or fiction? You be the judge.
That sort of sums up my last trip to Pocosin Lakes and Mattamuskeet National Wildlife Refuges. It was beautiful, but difficult. Made so by the intense heat and humidity on the day of my tour last week. The heat was stifling, but, my clients and I managed to survive, and see some interesting wildlife as well. My friend, Petra, had once again helped arrange a tour for some folks from the Netherlands (this is the fourth trip I have guided for wonderful guests from the Netherlands). And, like the others, they wanted to see bears, so I met them in Plymouth early Thursday morning for a trip over to the Pungo Unit of Pocosin Lakes NWR. After driving through the refuge and seeing mainly butterflies and a few birds, we parked and walked down one of my favorite dirt roads, hoping for bears. Tracks in the mud showed they were around, but none showed themselves as we strolled and sweated a mile down the road. We did have a couple of Bald Eagles, some woodpeckers, toads, lizards, and more butterflies, but no bears for the first part of the walk. After reminding folks that you should always look behind you, one of my clients did just that, and spotted a bear. Of course, it was only a hundred yards or so from our parked car and here we were about a mile away. The grasses and weeds had grown up in most of the side paths, so we skipped those and headed back, spotting a couple of more distant bears along the way. Closer to the car, a large bear was ambling along the edge of the crop field on the other side of the canal, headed in the same direction we were walking. As we got closer, I saw it suddenly turn around and start walking in our direction, so we stopped.
Large Black Bear passes by across the canal (click photos to enlarge)
He passed by on the other side of the canal, partially obscured by the tall weeds. He was a big guy, maybe 300+ pounds, I am guessing. And it looked as though he has seen his share of scuffles with other bears, from the look of his ears and coat.
The bear swam across the canal after moving past us
The wind was in our favor but I think he heard our loud camera shutters and picked up the pace, running down the far side of the canal about one hundred yards, where he swam across and stood in the road looking back at us. Needless to say, that was quite a thrill for us all. The morning turned out pretty good for bears with twelve sightings for most of us (one person saw one more run across a road that the rest of us missed). The highlights were the big guy across the canal and two sightings of bears in trees – a mother with two cubs in one tree, and a lone cub lounging in the shade of another tall tree. We all agreed that cub had the right idea for such a hot day – get in the shade up where there was some breeze, drape your legs over a large limb, and chill out. A good spotting scope really helps you appreciate the behaviors of wildlife in these types of situations.
The short boardwalk loop through the swamp is one of my favorite stops
We decided to run over to nearby Mattamuskeet NWR to see what else we could see. There were the usual waders, Great Egrets and Great Blue Herons, plus lots of turtles in the canals. People were catching Blue Crabs in several places (a very popular summer activity at this refuge). But, after driving the length of Wildlife Drive, no foxes or other wildlife were seen. We stopped to walk the short boardwalk through the swamp as it is one of my favorite hikes at Mattamuskeet. It was made more appealing on this afternoon due to the shade. As is often the case when I am leading a group, I left my camera in the car. My goal is to find things for the clients to observe and photograph, plus I always joke that by leaving my camera behind, it increases our chances of seeing something interesting. Well, it did not disappoint.
Golden Orb Weaver (photo by Petra Glorie)
I spotted a huge web of a Golden Silk Orbweaver, Nephila clavipes (also called the Golden Silk Spider and the Banana Spider) . This female provided a great photo opportunity in the late day sun, and I thank Petra for the use of one of her excellent images. This is one of our largest spiders, the female being up to 1.5 to 2 inches in body length, with a leg span of up to 4 inches. Males are tiny, averaging only a little over one-quarter of an inch in body length. The spider is named for the unusual gold-colored silk in its web. And the web is huge, spanning a few feet across the swamp. I don’t remember seeing them at Mattamuskeet before, but I am not down there as often in the summer. Records have shown a range expansion for this species, especially in the past two decades. I remember seeing them in the Wilmington area fifteen or twenty years ago, and then seeing them gradually move northward and inland. They are now found from North Carolina (primarily the Coastal Plain) south to Texas. And for those of you cringing at the thought of this huge spider moving into your neighborhood in the near future as range expansion continues with climate change, at least we can be thankful it is such a beautiful species.
…from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.
~ Charles Darwin
Spiders are everywhere in these woods now, so I decided I should probably photograph some and write a few observations to share. The other day I went downstairs to observe one that has repeatedly strung a web across the basement door, requiring me to duck or sweep a hand every time I want to go out to fill the bird feeders. But, as often happens in my wanderings, something else extraordinary caught me eye. It must have flown inside while I had the door open gawking at the spider dangling just outside. I saw it creeping along the inside glass on the door and immediately forgot all about the spider. This was a critter that I had seen only a few times, and never photographed, and here it was, and me with camera in hand. Unfortunately, it was in a strange location for a picture, waist-high on the inside of a double-pane glass door. But, my motto is always take the photo, and try to get a better one later.
First attempt at a photo of my mystery bug (click photos to enlarge)
Okay, so maybe this pic doesn’t scream, really cool insect!! I moved closer, took a few more, and, in Lightroom, wiped out the second of the two reflections of the bug caused by the door glass.
Green Mantisfly and reflection on door glass
Now, maybe you can see why I was so excited. This is a Green Mantisfly, Zeugomantispa minuta. It is only a little over a half inch in length, and is definitely distinctive in its design.
Close up of head and front legs
It has raptorial front legs, complete with spines for holding its prey. Those, along with the head and large eyes, make this look like a close relative of some sort of mantid.
The Green Mantisfly looks like a cross between a lacewing and a mantid
But, the rest of the body looks more like a Green Lacewing. In the wonderful reference, Kauffman Field Guide to the Insects of North America, the Green Mantisfly is described as resembling a science experiment gone horribly wrong. I couldn’t agree more. And then I read about its life history, and it took on a whole new level of weirdness.
The Green Mantisfly has an unusual life history
While the adult feeds on a variety of small insects (as you might suspect, given its mantid-like front half), their larval habits are more surreal. Larvae consume spider eggs inside the egg sacs. There are a few species of mantisfly in our region, including one whose rear half resembles a wasp. Depending on the species, the larvae may actively seek out spider egg sacs and then enter them, or it may hitch a ride with a female spider. When she starts constructing an egg sac, the mantisfly larva will enter it and dine on the eggs. Some have reported that, if the larva instead grabs onto a male spider, it will wait and transfer to a female when the spiders mate. The well-fed larva then pupates inside the spider egg sac and later emerges from it as an adult. Once again, I am astounded by the complexities and surprises found right outside (or, in this case, inside) my door.
There will always be scary predator eyes looking out at us from the bushes – it’s just that most of the time they are mounted on the rear end of a happily munching caterpillar.
~The Caterpillar Lab, Sam Jaffe, Director
On a walk at Yates Mill Park the other day, I came across one of my favorite caterpillars. My first glimpse was of a darkened blob on a leaf as I walked past a fence. The leaf was on a climbing vine of a Greenbriar, Smilax rotundifolia.
Turbulent Phosphila larvae on Greenbriar leaf (click photos to enlarge)
When I stepped closer, I knew what the blob was…a group of tightly packed caterpillars! These striking larvae go by the unusual name of Turbulent Phosphila, Phosphila turbulenta. I discussed this species in an earlier post and am always delighted to find them. The name intrigues me…I understand the turbulent (characterized by conflict, disorder, or confusion) part…they are gregarious feeders in their early stages and can appear quite confusing when seen in a mass on the underside of a Smilax leaf (their only host plant). Sam Jaffe, an incredible photographer and educator on the subject of caterpillars, described them as looking like a mass appearing more like some strange outdoor QR code than biological life. Well said, Sam. It is the Phosphila part that has me baffled. If you break it down into its Greek roots, it means “phos” = Light, and “phila” = loving….light loving.
Turbulent Phosphila on Greenbriar stem
These guys usually hide on the underside of leaves as larvae or are clustered along a stem, hardly the behavior of a light-lover. Perhaps the adult moth is especially attracted to light? I don’t know. Perhaps the bright white spots on the rear of the caterpillar resemble bright points of light to someone? Not sure. Those spots are believed to function as fake eyes, and are more prominent and numerous than the eye spots on the anterior end of this species, making it tough to tell which end is which.
Turbulent Phosphila larvae, head downward, on Greenbriar stem
Whether the fake eye spots on the rear create a distraction for would-be predators away from the more vital head portion of the caterpillar, or they just serve as a startle and potential threat factor when seen in a grouping, the impact is one of confusion when you first look at these larvae. David Wagner, in his excellent reference, Caterpillars of Eastern North America, states that both the coloration and behavior suggest that these caterpillars are chemically protected. Whatever the case, they provide me with a wonderful visual treat every time I encounter them.
Don’t ask yourself what the world needs. Ask yourself what makes you come alive, and go and do that, because what the world needs is people who have come alive.
~Dr. Howard Thurman
It happened again. Ten months go by, another 100 blog posts. So, as I have done in the past, I mark this passage of time with a brief review of some of the highlights from the last one hundred blogs. I suppose it is an excuse for me to look back and remind myself of how lucky I am, how much is out there to observe and enjoy, if I only make the time to get outside.
The third one hundred started with a trip to the Low Country of South Carolina.
Botany Bay (click photos to enlarge)
Botany Bay turned out to be as beautiful as images I have seen…I need to go back when low tide is at sunrise.
River Otter with fish
As always, Pocosin Lakes and Mattamuskeet National Wildlife Refuges provided many highlights of my last one hundred posts.
Tundra Swan at sunriseBald Eagle stirs up a flock of Snow Geese
This is especially true during the winter months, when the area’s lakes and farm fields fill with wintering waterfowl…
Young Black Bear pulling at a Cross VineRed-winged Blackbirds create a feathered tornadoGray Fox waking up from a nap along Wildlife Drive
…and other wildlife.
Spring Peeper callingDwarf Crested IrisPine Warbler male in blooming Redbud tree
Spring brought lots of amphibians, wildflowers, and beautiful colors…
Bald Cypress along Conaby Creek on the Roanoke RiverProthonotary Warbler male singing at nest cavity
…along with a couple of canoe camping trips along the Roanoke River.
Eastern Chipmunk in the yardSpider just after molting
And I spent a lot of time wandering the yard, discovering what my wild neighbors are up to.
Carolina Chickadee bringing food to nest boxFour Wood Thrush nestlings
I was happy to help provide some footage of nesting birds and what they feed their young for Hometown Habitat, an upcoming educational video on the importance of native plants.
Pronghorn Antelope at sunriseGreat Gray Owl chicksGrizzly siblingsRainbow in Hayden Valley
And I was lucky enough to spend another wonderful couple of weeks in my favorite place, Yellowstone, leading a trip and observing some of the magnificent wildlife of the region.
Black Bear cub watching us from a treeYoung bear looking down as I walk through the forest
I spent a lot of time with bears these past few months, watching them, and being watched. A very good year for bears, I must say.
As the summer ends and BugFest approaches (September 19 at the NC Museum of Natural Sciences in Raleigh), my thoughts, and camera, seem to turn to caterpillars and all things Lepidopteran.
Copperhead closing in on a cicada (too late, it dropped from its shed)Phidippus putnami – close up of eyesEastern Dobsonfly maleFreshwater Jellyfish in the local pond
As always, I discovered some fascinating things as I wandered, and this has been a very productive few months for those “ah-ha” moments…Copperheads following cicada nymphs up into trees when they are emerging in order to dine on them; cool spider eyes; weird insects in the yard and at the moth light; and the return of the jellies to my swimming hole…wonder what the next one hundred will reveal? I can’t wait…
Reality is easy. It’s deception that’s the hard work.
~ Lauryn Hill
Nature is full of deception. And now it is being touted by none other than the New York Times. A recent article on caterpillar defenses caught my eye. Researchers studied the late stage larvae of the Canadian Swallowtail (Papilio canadensis). The larvae are plump, green caterpillars with distinctive eye spots that are said to make them snake mimics. This type of mimicry is fairly common in the caterpillar world and is thought to provide some protection from avian predators. When I looked at the photos in the article, they looked very similar to something I found in the yard a couple of weeks ago.
I posted a photo of the third instar larva of an Eastern Tiger Swallowtail (Papilio glaucus) in an earlier post. Like the early instar larvae of many species of swallowtails, it is said to resemble a bird dropping. These so-called bird poop mimics usually have a dark base color and at least one conspicuous white splotch on their body (usually near the center). But, the last two instars of this species look very different.
Eastern Tiger Swallowtail larva in later stage
I checked on the swallowtail caterpillar in my yard a week after that first photo and it looked almost exactly like the snake mimic photo of the Canadian Swallowtail larva. Gone was the bird dropping costume and in its place was a light green body with fairly prominent fake eye spots, and a slightly swollen anterior portion, giving it the appearance of a snake’s head.
The larva rears up in a “snake strike pose” when disturbed
When the caterpillar is disturbed (I blew on it and touched the leaf for the photo above), it arches its body making the eye spots become more visible and enlarging the “snake head” region. In the recent study reported in The New York Times, researchers studied the predator deterrent efficacy of this snake look-alike strategy by creating tasty plain green “pastry caterpillars”. When placed on twigs, birds readily ate them. They then added eye spots and snake-like heads, and the birds tended to avoid them. In fact, adding just eye spots caused about the same rate of avoidance. This caused them to wonder….If real caterpillars don’t gain extra protection from extra deception, then how could their disguise have evolved?
They decided to present their pastry larvae to day-old bird chicks who had never seen a snake, theorizing that birds may have an innate fear of snakes and snake-like objects. Here are the results…When the chicks were offered simple green cylinders, they grabbed them. But when eye spots were added, the chicks became wary. Consistent with earlier research, the scientists found that adding a snakelike head didn’t make the chicks any more fearful. Over the next two days, the scientists presented the chicks with pastry caterpillars five more times. By the end, the chicks had learned that cylinders with eye spots were, in fact, tasty snacks. That was not the case when the chicks were presented with pastry caterpillars with both eye spots and snakelike heads. Even at the end of the study, the chicks were still fairly wary of the more realistic mimics. They concluded that birds have evolved a fear of snakes and that just a few characteristics, like eye spots, can make them wary. But, birds and other animals, can learn to distinguish between similar-looking objects, which may have driven caterpillars to evolve more elaborate disguises in order to keep fooling the birds.
After more provocation, the caterpillar extrudes its osmeterium, which happens to resemble a snake’s tongue
And, if you are going to have a snake’s head, you may as well have a snake’s tongue. Turns out, all members of the family Papilionidae have a special glandular organ, called the osmeterium, that can be extruded from just behind their head capsule when they are threatened. The forked shape resembles the forked tongue of a snake, further reinforcing this disguise to any would-be bird doubters. The osmeterium also produces secretions with a distinctive and disagreeable odor. These secretions have been shown to repel many invertebrate predators such as ants and mantids, but are not believed as effective against most vertebrate predators.
So, it seems this group of caterpillars are quite adept at the art of deception. From bird poop to strike poses, they offer an array of distasteful, or possibly even dangerous-looking, meal options for foraging birds. I am always fascinated by this long, slow dance of predator and prey and how it plays out in terms of behavior and appearance.
The worm poop is raining down like a black sleet storm. Got to remember not to open mouth while looking up.
~Ken in Texas, on Unofficial Allis Chalmers Forum, talking about Catalpa Worms
A little over a month ago, I received an email from a neighbor about some caterpillars that were “munching their way thru one of our catalpas”, along with a photo. He also mentioned he had heard these were considered “the gold standard of live bait.” And he was right, they were, indeed, the famed “catalpa worms” (also called catawba worms), a species I had always wanted to see up close. I had seen evidence of their feeding many times, but the caterpillars were always too high up in the tree to photograph. As luck would have it, time slipped away and I did not get down to my neighbor’s place in time to see that batch of caterpillars. But, last week, I went down to get a couple of plants at his nursery (Cure Nursery, a native plant nursery) and was stunned to see another group of early instar caterpillars on those same Catalpa trees.
Catalpa tree branch showing caterpillar feeding (click photos to enlarge)
I was stunned because I always assumed there was only one generation per year, as the few trees I have seen around here are always stripped of all their leaves by June or July. In fact, the caterpillars will probably not survive on my neighbor’s trees because the leaves have all been stripped and have barely started to leaf out again. Those few leaves will surely not be enough feed all of these caterpillars. So, I gathered a few of the larvae up and managed to collect a few leaves from sapling sprouts at another roadside location.
Catalpa Sphinx are gregarious feeders in early stages
These boldly patterned larvae are actually the caterpillars of the Catalpa Sphinx, Ceratomia catalpae. Female moths lay large clusters (sometimes numbering in the hundreds) of eggs only on Catalpa trees. Early instars of the larvae feed in groups, turning to solitary feeding in their later stages.
Catalpa Sphinx larva
As with most members of the Family Sphingidae, the larvae are adorned with a prominent tail spike, which seems exaggerated on the early instars.
Pair of feeding larvaeThey are eating machines
And, like most caterpillars I have seen, these guys are eating machines. In the short time I was photographing them, just a few managed to consume about half of one of the large leaves I collected. And when they eat, they poop (you can see some frass, caterpillar poop, in the first photo of this pair). So, if you are standing under a large Catalpa tree having perhaps hundreds of large caterpillars up in its branches, I suppose it can sound like rain pouring down. Caterpillars eventually climb down the tree trunk and pupate in the ground nearby. And, surprisingly, it is common to have two or more generations in a season.
Fishermen swear by the later stages of these larvae as fish bait
In looking online, it seems the large (up to 3 inches) caterpillars are, indeed, a favorite of fishermen. In fact, their value as fish bait (especially for bass and catfish I am told) was mentioned when the species was first described in the 1870’s. Apparently, the skin is tough enough to hold the larva on a hook better than many live baits. So, whether the caterpillar is a pest when it defoliates your Catalpa, or a valuable commodity, depends on your perspective, as is so often the case when it comes to things in nature. For me, it’s enough to just have the chance to finally see some of these beauties up close.
Aerodynamically, the bumblebee shouldn’t be able to fly, but the bumblebee doesn’t know it, so it goes on flying anyway.
~Mary Kay Ash
Pink Turtlehead, Chelone lyonii (click photos to enlarge)
On a recent visit to Mount Mitchel State Park I was amazed at the abundance of wildflowers along the high ridge lines in the park including flows of White Wood Asters, Cut-leaved Coneflowers, Pale Jewelweed, and smaller clusters of Filmy Angelica and Pink Turtlehead. And everywhere we went, we could hear the sound of pollinators buzzing around the flowers. It turns out, most of the buzzing was coming from very busy bumblebees. Along the trail to Mt. Craig, I stopped to watch some bumblebees struggling to pollinate what must be one tough flower to get into – a Pink Turtlehead, Chelone lyonii. Here is a short video:
Seems as though the Pink Turtlehead is reluctant to give up its reward to just any ol’ pollinator. The upper lid of the flower overlaps the lower like a turtle’s beak, hence the common name. The male parts mature first, and when the pollen is ready, the flower is very hard to pry open so only the strongest of pollinators, like bumblebees, can get the job done. When the pistil starts to mature, the flower relaxes a little and is easier to enter, but it requires a long-tongued insect to reach the nectar. Again, certain bumblebees fit the job description. The advantage for the flower to requiring such pollinator specificity is that it helps ensure their pollen gets carried to other flowers of the same species and doesn’t get wasted on different flowers.
Bumblebees as a group (there are close to 50 species of bumblebees in North America) are very efficient pollinators compared to most other insects that visit flowers. They are fast workers (some research indicates they visit twice as many flowers per minute as honeybees); because of their generally larger size, they can carry heavier loads of pollen, enabling them to make longer foraging trips; their large bulk also aids them in making contact with the stamens and pistils of the flower, thus ensuring better pollination; they tend to be fuzzy, which causes pollen to stick to their bodies better; and they can forage at lower temperatures and lower light intensities than most other pollinators. The latter may be especially important in an environment like Mt. Mitchell, the highest peak in North Carolina. Indeed, at about 5:30 p.m. one evening on our camping trip, I noticed a swallowtail butterfly that landed in a fir tree at our campsite to roost for the evening (it had clouded up and was threatening rain). Meanwhile, the bumblebees still buzzed about their business for at least an hour more, and started much earlier the next morning, in spite of the drizzle.
Here’s another short video of pollinators actively working the flowers of a Filmy Angelica, Angelica triquinata.
So many flowers, so little time, especially at these high elevations. Hoping to get back up there in the next week (high of 67 degrees reported yesterday:) and see if the bumblebees are still hard at work. I am betting they are.
Roads End Naturalist 