Picking up where I left off on my last Cecropia post, here are a couple pictures of the caterpillars later in the 3rd instar phase. This first one shows an early third instar above one in the second instar phase. They certainly do grow from one stage to the other, don't they? This third instar is a little older. The body colors have muted some, and the blue pedicles are now showing -- at the tail end and in front of & beside the large red ones near the head.
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This Cecropia caterpillar is stretching into a nice pose just after molting into the third instar phase. It's coloration is still pale -- the pedicles supporting the spiny protective hairs haven’t darkened yet, and the “eye” patches on the head have yet to appear. The white breathing holes (spiracles) are clearly visible in this picture, between the black spots on it’s side. ![]() Cecropia caterpillar (Hyalophora cecropia) molting into 3rd instar. I caught this caterpillar working out of it’s old skin, begining the third instar phase. I came across it well into the process, but it still took several minutes to finish. It seemed to expand and contract it’s body in waves to push the old skin back and off. It finally cleared itself completely by curling into a tight “C”, pulling it’s rearmost portion out of the old skin. I’m constantly amazed at the details I see through the camera when doing macrophotography. I’m quite often surprised again when I edit the images! This series of shots, as the caterpillar worked it’s way out of it’s old skin, is one good example. Looking through the images at full size, I noticed the claws of the “real” front legs were still on the shed skin. I had assumed only the skin was shed, but I see that the outer layer of the claws shed off, too! The following six pictures are enlargements from portions of the full size images. I was also surprised to find a mite crawling around on the shed skin as the caterpillar was working it off. ![]() Small mite on shed skin. I don’t know if the mite is a parasite of the caterpillars, or if it just happened to be there -- or if they feed on the discarded skin. But, I will be looking for them in the rest of the images! ![]() Small mite near shed skin. This is the same mite, later in the series of shots, as it crawled off the shed skin onto the lilac leaf the caterpillar was on. ![]() Detail of silk threads on the leaf's surface. Did you also noticed what looks like fine hair on the surface of the leaf? They lay flat, though, unlike a leaf's protective hair. These are fine silk threads spun unto the leaf's surface. They may have come from the caterpillar, though I didn't see them prepping the spot before shedding their skin. More likely they are the anchor threads of small spiders that travelled the leaves before I brought them in from the lilac bushes. The tiny claws of the rear prolegs are snagged onto them, making a good anchor to help pull the old skin off. Here's a closeup of the head -- another crop of one of the full-size shots. You can clearly see the mouthparts and feelers that help guide the leaf into the serrated mandibles. The mandibles don't chew the leaf, but cut it into small crescent shaped pieces to be digested in the stomach. The 5 simple eyes on this side of it’s head can also be clearly seen, since the black "eye spots" haven't developed yet. Notice the pink, out-of-focus "blob," on the caterpillar's head -- just above the jaws in the shot above? The fast travelling little mite has found its way back onto the caterpillar. ...an unintended guest that came in with the leaves. ![]() Third and fourth instars of the Cecropia caterpillar. Here's how the late second and early third instars compare in size and coloration. The third instar certainly looks more striking -- and formidable! The colors of the pedicles have darkened, the "eye" spots have appeared and the bright body color and four red pedicles behind the head stand out as a warning to larger predators. Stay tuned for the next in the series, as the caterpillars continue to grow and begin to molt into the even more colorful fourth and final instar! Please feel free to comment & let me know what you think of the series so far! After the caterpillars hatched and began to grow, I wished I had counted the eggs; they didn’t move nearly as much as the caterpillars! While I can’t say for sure how many eggs were laid, there were around 100 caterpillars, between those I released and the ones I kept until they spun their cocoons. As they began to grow, and eat so much that I couldn’t keep them fed throughout the day, I experimented by adding Maple leaves as a different food source. But, they didn’t touch them -- unless you count walking across them to more lilac leaves! I knew Maples were one of their preferred foods, but apparently they have (or prefer) to remain with one food source, once they’ve begun on it. ![]() Cecropia caterpillar (Hyalophora cecropia) molting into 2nd instar phase. To prevent underfeeding them, I let a couple dozen at a time free into the Lilac bushes in the yard. I repeated the earlier experiment by letting one caterpillar go in a Maple tree, but after checking on it over several hours, it still hadn’t eaten anything. So I brought it over the Lilacs, too. The cecropia larvae grow through 4 stages (or instars) between hatching and spinning their cocoon. They pupate over winter and emerge as adult moths the following summer. Here is a brand new second instar Cecropia caterpillar just after molting. The old skin is momentarily caught on a protective spine at its back end. ![]() 2nd instar (left) and late 1st instar Cecropia caterpillars (Hyalophora cecropia) on Lilac leaf. For comparison, this image shows the first two stages -- a late first and early second instar. The second instar is certainly more colorful, with stouter pedicles supporting the protective spines. If you look closely, you can see a row white spots on both of these caterpillars' sides. These are the spiracles, where air enters into their respiratory system. Adult Cecropia moths have no mouthparts or digestive system and only live a few weeks after emerging from their cocoons. While I let her go shorty after she had laid her eggs in the terrarium, she didn’t lay any more and didn’t fly off. So I brought her back inside. She died shortly afterwards, but I was able to get some close-up images showing the scales on her wings and a detailed shot of her head, showing the lack of mouth parts. My next post (the forth in this series) will show the caterpillars as they molt into their third stage. The third instar has fewer black spots, and four of the pedicles near its head grow larger and turn red.
Nine days after taking the pictures of the Cecropia moth and her eggs in my last post, I had the time to photograph them again. By then, the last of the eggs had just hatched. From a distance the caterpillars looked cute and fuzzy, but up close they seemed formidable enough to make just about any predator back away! This one has just chewed it’s way out of the egg. If you compare it to one of the later images, you may notice the pedicles that it’s sharp little guard hairs grow out of are a lighter yellow or orange color just after they hatch. They soon turn as dark as the rest of their skin. The "hair" you can see on some of the eggs came from the female as she glued them in place. The glue gives the eggs the pinkish color -- and the darker orange spots where the glue pooled as it dried. ![]() Life size caterpillar and eggs The picture above is uncropped, taken at 5x magnification. To give you an idea of the caterpillar's actual size, if the image to the left is just under one inch (24mm) tall on your monitor, you’re seeing how tiny they really were! The eggs in these two images were laid on the glass of the terrarium. I propped up a white sheet of paper a few inches behind the glass to lighten the background. The caterpillars spent several minutes on the eggs after they hatched. I don’t know if they were chewing away at more of the eggshell, or just letting their guard hairs stiffen up. Either way, they were soon off looking for a nice tender leaf to start munching on. To begin with, it was fairly easy to keep them stocked with a fresh supply of leafy lilac twigs in florists’ vials. Within a month, however, that had changed to a daily task! The caterpillars in today’s post are all in the first instar stage. By nine days after I had taken these pictures, several of them had molted for the first time, growing bigger and more colorful.
You'll see for yourself in my next post! One of the nice rewards of being a nature photographer is all the great nature related photo opportunities people tell me about. This post, the first in a series, follows the life cycle of the Cecropia moth (Hyalophora cecropia) from egg to cocoon, and is the fruit of one such call. One of my brothers found a Cecropia cocoon and brought it home so his family could watch the moth emerge. They released it on their deck once it was ready to fly, but it liked the spot and stayed there, immediately going about attracting a mate. The females attract males by releasing pheromones, so it works to it’s advantage to stay put once it finds a good spot. Studies show that the male can home in on the female’s pheromones from over 7 miles away! She was successful, and the next day found her busy on the deck with a male. Since my brother and his family were going on vacation shortly after this and wouldn’t be able to watch it lay eggs, he wondered if I was interested in “baby sitting.” It seemed like a great opportunity to photograph the moth laying eggs, and the caterpillars as they grew. A little quick research showed that their foods of choice includes lilac and maple, along with birch, apple and cherry. We have plenty of maple and lilac in the yard. So I cut several lilac twigs and set them into small, rubber capped florists’ water vials to keep the leaves fresh. Then I fit an old aquarium with a screen top and set it up on our porch for the anticipated new arrivals. I didn’t have long to wait. Within a couple days the female was laying eggs. Unfortunately, I was at work and wasn’t able to capture that shot. It was, however, quite a prolific egg layer and I could see I would be busy with feeding, cleaning up after, and taking pictures of little caterpillars! Once the weekend came, I released the adult onto one of our clumps of lilacs and took these pictures. It didn’t fly off, though, and before nightfall I brought it back inside to avoid predators. The moth stuck the eggs in place with a liquid "glue" that dried the brown color you see on these eggs.
Within another few days, small black caterpillars began hatching from the eggs. Stay tuned for more pictures of the caterpillars as they grow! |
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