I tried to resist doing this, but have failed miserably. This isn't the first time I've raised cecropias, and I do consider it an enjoyable experience. However, it's also time consuming, and I didn't want to spend the time. A friend had purchased the eggs, and she didn't want the whole batch. I ended up caving.
The adult moth on this page is from my first rearing experience. My camera wasn't all that great back then, plus I didn't keep a good photo record. The adult photo (very tacky background) is for reference, so visitors who don't know can see what a cecropia is. I think they are delightfully impressive, beautiful creatures. I like their caterpillars, too.
My friend gave me three eggs on Sunday, 21 June 09. I promptly brought them home and placed them in a clear, lidded deli-style container. It's important to keep the container sealed so the eggs don't dry out. These eggs were ovaposited on 14 June 09. I expect the caterpillars to emerge about two weeks after the ovaposit date, around 28 June 09. The tiny eggs are about 2mm each. The brown stuff is fluid and glue from the female moth. White is the normal color of the eggs.
Cecropias are indigenous to the eastern half of the North American continent and are common, but few people ever see them, it seems. The adult moths fly at night. The caterpillars live high in the treetops. Their habitat is typically the edge of wooded areas. Fifth instar caterpillars found in the wild are usually hopelessly parasitized and will not survive pupation. However, there are those who, like me, think it's great fun to rear these bugs. Those who make a hobby of it typically sell their bugs as eggs, cocoons, or collection specimens. If you're searching for livestock, I recommend contacting my source, Bill Oehlke.
25 June 2009: My tiny bugs ate their way out of their eggshells today, as that is how they escape. Eating is about all they do. Two of the three were still wearing their eggshells, which I eventually removed by hooking each with a pin and dragging it off. The hatchlings are about 3 mm long, and I love my camera's macro ability.
My gut feeling was that they'd hatch today, as the weather has been extremely warm. However, I didn't think to check until my source-friend emailed me to say she had two bugs. I promptly checked and found three. So, let the feeding frenzy begin!
30 June 2009: The little bugs are very near the end of their first instar (caterpillar substage) and are about 7mm. I first noticed the slight color change yesterday evening. So far, the three have eaten one whole birch leaf and almost half of another. They'll molt soon, so they can continue to grow. Young cecropias like to stay close together.
2 July 2009: Today, the little bugs have begun their first molt -- all three at once, which is good, for me. Photos at right are two slightly different views of same bug; the other two are on a different leaf, but I could get a better camera view of this one. They have grown much during the past week, and their skins have become too tight for them. They need new skin. Each has made a little silk pad on the leaf and then attached its hindmost legs to it.
They will remain in this slightly curled position at least for a day, unmoving. When the process is near completion, their head-skin will fall off, and they will ripple and crawl forward so that the old skin works back along their bodies until it forms a little bunch that is left behind on the silk pad.
We are having a significant cold spell at present, with overcast skies and daytime temperatures in the sixties. Such weather slows down bug development considerably.
3 July 2009: By the time I checked the bugs today, they had all completed their first molt. One had already eaten most of its skin, but the other two were still at rest. Photo shows newly molted second instar caterpillar standing just ahead of its shed skin.
I've been feeding these bugs white birch leaves. I keep the leaves fresh by pushing the stems into a floral water tube, which fits nicely into their container. Inside the tube, I keep a waterlogged piece of paper toweling.
There are a number of plants that cecropias will eat. Once started on a specific plant, though, the caterpillars will want to eat only that. A few other options (list not exhaustive) are: maple, willow, apple, elm, lilac. I tried lilac the first time I raised cecropias and they all absolutely refused to eat it. I switched to birch.
4 July 2009: Following a day of eating, the second instar caterpillars have a more well defined look. This photo is so magnified; the bugs are really only about ½ inch long. The wider end is the front end. So far they are not big eaters.
8 July 2009: The caterpillars are well into their second instar and have grown to about ¾ inch. They are still residing in a small, clear, sealed container and are eating about one leaf every two days. Such a nice environment -- no predators to worry about. In the wild, few caterpillars ever survive long enough to become adult moths. The last time I raised cecropias, all 24 caterpillars cycled through to the adult stage. That was a huge project!
9 July 2009: I checked the caterpillars late tonight and discovered they are poised for their second molt. Due to poor lighting, I had to use flash which turned out to be a positive thing. Their colors are brighter, their shiny parts are sparkly, and strands of silk can be seen on the leaves.
All lepidoptera larvae produce silk. Bombyx mori was domesticated for the sole purpose of producing commercial silk, as the quality of its silk is unique. There is also a wild moth used in Asia for silk production, saturniidae antheraea pernyi. It is related to our indigenous saturniidae antheraea polyphemus moth. Cecropia is also a saturniidae moth and produces a large amount of silk for its cocoon; however, it is not used commercially.
Many lepidoptera do not use their silk for making cocoons. Butterfly larvae do not make cocoons, but use their silk to anchor their pupae, called chrysalises. Some also use their silk to create a sort of scaffolding all over their food plant.
10 July 2009: I checked the caterpillars at about 8:00 p.m. and got treated to a live skin shedding in action. The process was just beginning, with the new skin splitting through the old just behind the head. I had to set up the camera so missed all that. Got some blurry photos, too, in my haste. Oh well. Anyway, click on the thumbnails to view larger images of the process. Enjoy!
The third instar is very colorful. The caterpillars are still quite small, probably under an inch.
11 July 2009: Today's first project was to create a new habitat for my bugs. I decided they needed more space, more food, more stuff to crawl around on, and a way for me to stock them up so I could leave them unattended for a couple days if necessary. For this I used a sour cream container with a lid and an ice cream pail with a lid. I punched a couple holes in the sour cream lid, filled the container with water, and poked a few leafy twigs through the holes into the water. This I set inside the ice cream bucket, and tucked the leaves and twigs inside so I could put the lid on if necessary. The caterpillars happened to have congregated on a single leaf in their old container, so I pulled the leaf and set it on top of the sour cream lid. Within a few minutes, all three had left the leaf and climbed in among the twigs and foliage. They spread out from each other quite a bit and are now just sitting around looking very content. I do believe the bugs are happy.
13 July 2009: These third instar cecropias are very handsome. The interesting color variation continues, as one has much more black coloring on its knobs. This darker caterpillar seems to be mostly green otherwise, while the other two have an indistinct blue marking down the center of their backs. These two show more blue and yellow in their knobs. I captured the face of one, as it was eating on the edge of a birch leaf. I find a weird humor in how caterpillars reside on their food plants. It's kind of like if we humans ate our houses. When we finished one, we would move to another and start eating it. The caterpillars are now about 1.25 inches. Click on image for larger view.
16 July 2009: This molt is commencing in less than a week since the last one. Top photo caterpillar is forming a silk pad to anchor itself for molting. Middle photo shows rear end of caterpillar poised for molting; flash reveals strands of silk on the leaf. Bottom photo shows head of poised caterpillar. Note that the forelegs are drawn up against its body and its head is curled over them -- the prayer position. This one's skin is beginning to loosen. Click photo for display of larger version.
Caterpillar at left has completed its third molt -- to fourth instar. I had to edit to achieve fairly uniform focus (combined two photos). The old skin is at the rear. Its spiracles are clearly visible -- the white circles. These appear on either side of the caterpillar, one pair per segment, and are the openings through which it breathes. This bug is about 1.5 inches long.
22 July 2009: The fourth instar cecropias have gotten rather huge. Fully stretched, they are almost two inches and plenty fat. They hate being away from their food plant, and because they are what they eat and they aren't too smart, when they get near each other, they think they've found their food plant. They certainly smell like concentrated food plant.
Photo makes it look like the one on the right is biting the other, so that the one on the left is screaming out in pain.
23 July 2009: I love this pose. Click for larger view.
26 July 2009: I had to leave the bugs for the weekend, so set up the worm coop for a long period of neglect -- two days. All three caterpillars did very well, but I bet they enjoyed the fresh air when I popped their lid upon arriving home, as it gets rather stale smelling in the closed container due to all the frass. I found them in molting position, after having defoliated just about all the yummy leafy twigs I left for them, but that's what they do. Now we wait for the enormous fifth instar.
28 July 2009: Shortly before the actual skin shedding, the caterpillar's old skin looks tight and kind of discolored. The face plate is separating. The new skin can be seen through the old skin at the base of the knobs.
The molting caterpillar crawls out of its skin, which looks so cool. I ended up having to assist this one, as it had lost its grip on its silk pad, probably having been freaked out by an earwig that somehow found its way into the container. I pinch-held the rear end of the skin while the caterpillar crawled out, and finally pushed what was left off with my fingertips. The freshly shed old skin felt very moist on the inner side and behaved kind of like elastic.
Once again, I had to leave for an overnight trip, so left the caterpillars on their own with plenty of food. Upon my return, I found them to be quiescent, but they had eaten a lot and made quite a mess, as usual.
3 August 2009: The fat caterpillars make quick work of a single leaf. Glad I'm not Dawn, with twelve to feed. Their crunching can be heard. Stretched, each is around three inches. They are chunky, heavy masses -- a ten course meal for any bird or rodent, a banquet filled hatchery for wasps and tachinid flies. Such is the insect world. It's estimated one in one hundred of these survives to maturity. A little human intervention can't hurt.
I read that a certain non indigenous tachinid fly was introduced to curb the population explosion of gypsy moth, but the result has been that the thing likes indigenous saturniids, like cecropia, luna, and polyphemus, and so saturniid populations are declining. Sad if that's true.
Hand feeding a caterpillar: Hold caterpillar moderately lightly between thumb and two fingers. Pick up a leaf with other hand and place edge of it perpendicular to caterpillar's mouth/face, against its mouth. I did this and my critter promptly started eating, then grasped onto it and continued eating, and eating, and eating . . . All the while I held it.
6 August 2009: I measured each fat cat today. Stretched, two of them are easily at least 3.5 inches, and the other is just under. They are massive, bulky critters; the size always amazes me, as they are not just long. They are putting away leaves at a phenomenal rate, keeping me plenty busy.
8 August 2009: The Blob! Call it the elephant of the insect world - a land dwelling herbivore. Fully stretched, this caterpillar is easily four inches and massive. All three are looking fabulous.
12 August 2009: Much is happening today. We had to leave town overnight on Monday, so I thought maybe I'd miss the great transition, but it waited till today, Wednesday.
When I arrived home yesterday, I promptly fed the hungry blobs because they had defoliated everything and were searching desperately. They promptly resumed their food fest, which must have gone on for most of the night because there weren't a lot of leaves left this morning. However, it was also obvious that they had stopped eating. One had already emptied its gut; the other two were waiting for the big moment. Those moments came a little later, and lasted for a lot more than a moment. I cleaned the bucket twice today, but am quite certain I'm now finished. That's a good thing.
Not long after "the big moment" is completed, the caterpillars begin their quest for the perfect place to form a cocoon. At this time, the keeper must make certain the bugs can't escape, as clinging to the food plant is no longer essential and the bugs have no interest in doing so. They move quickly now, having lightened their load considerably, in search of their perfect place, and it's up to the keeper to limit where they will look. If you lose your bugs to the crevices of your home, be assured that sometime during the winter a moth will eclose and make a big mess that you don't want. Also, if you have any pets or are prone to mice, be assured that your moth project will become a snack.
I've got two bugs who seem to be busy creating their cocoons, and one that's still prowling around. This is the prowler, and it's doing quite a contortionist display. Space is kind of tight in the worm coop, and I'm wondering if I'm going to end up with three interconnected cocoons. Could be interesting.
13 August 2009: Cocoon construction is well underway. Two of the bugs are very close together, so I expect their cocoons will be somewhat interconnected. The formation of the valve can be seen on both views. Cecropia uses a valve through which the moth ecloses; many other species dissolve a hole using a liquid enzyme the moth emits.
The cocoon is one continuous strand of silk. Silk is a protein produced by the caterpillar. It comes out of the caterpillar's mouth as a liquid, and hardens when it contacts air. The caterpillar also coats it with an adhesive to hold the cocoon together. In the silk textile industry, cocoons are boiled to kill the pupae and dissolve the adhesive. Of course, the textile industry does not use cecropias. Bombyx mori is the bug of choice. Nevertheless, to harvest cecropia's silk, the process would be the same, if one were aiming for reeled silk.
When my original batch of 24 moths were eclosing, several years ago, one happened to not be facing the valve -- a caterpillar goof. This was disastrous. The moth can neither turn in the tight quarters nor back out. I, of course, did not know what was going on. There was obvious activity in the cocoon, so I waited a day or two. The cocoon became quite juicy, yet the moth was obviously still alive in there. I decided to cut it open (very carefully). What I found was a very soggy, misshappen, rather colorless excuse for a moth.
Their programming marches on, whether the previous step(s) has gone correctly or not; there is no turning back. The moth had had to expand its wings and also release its wastes. The wings had nowhere to expand to, so they were the length of the moth, narrow, and were hardened forever in that awful shape. The moth's body was not velvety. All the hair and all the color apparently had been washed away by the juices. I was amazed the creature hadn't drowned, but it was very much alive. Poor thing.
Funny thing with these: When I raised 24 at once, they were just a big bunch of bugs. Raising three this time, I perceived individuals. I could tell all of them apart, and each had somewhat individualistic behaviors. One would eat out of my hand. It was also the most efficient eater of the bunch. It also ended up being the biggest caterpillar. I suppose I should make note of which bug is in which cocoon. Though Red Knobs started its cocoon last, it's definitely leading the pack in progress.
19 August 2009: The three bugs made three cocoons -- like I expected anything else. Two are kind of fused together, which I also expected. I haven't had time to do much with these other than peel them off the ice cream bucket, trim off plant matter, and toss them in the sour cream container after having cleaned it thoroughly. One of these days, when I do have time, I will likely cut one open (very carefully) to see what the bug within is up to.
Not sure whether I miss the caterpillars or not. Certainly, feeding them was getting a bit old, as was dumping the frass pile regularly. On the other hand, they could be kind of entertaining.
1 September 2009: I finally had a bit of time today to tinker with a caterpillar. Well, really, things have changed dramatically, which I knew would be so. I cut a cocoon open and found a very lively pupa inside. It's a girl! She is fat, healthy, and quite weighty. I'm impressed and pleased.
A peek inside the cocoon reveals a gross glob that is just the old caterpillar skin. It's quite dry and brittle. Beyond the skin is the abdomen of the brown pupa, which fits snugly within its cocoon.
Next is the back of the pupa. The head end is on the right. A wing is clearly visible behind the head and extending underneath. Its spiracles run along the abdominal segments at the bottom of the photo. The length of the pupa on this side is mostly abdomen.
Last is the front of the pupa. The head/face is the round thing at right. Directly to the left of the head are the foremost legs, tucked up neatly. Framing the head and legs are the antennae, one on either side, and framing all of that are the wings, which wrap completely around the front side. When pupation is completed, the eclosed moth will inflate its wings into huge, colorful, wondrous things.
Most of the pupa is quite rigid; however, the abdomen can be wriggled quite vigorously. This pupa is an energetic wriggler -- very entertaining.
Its antennae give this baby's gender away. Males have wider antennae.
By the way, this pupa is "Red Knobs."
A close inspection of any lepitoptera pupa will, like this pupa, reveal an interesting image of the adult insect it will become. I've raised many monarchs in the past, and though the pupa/chrysalis looks like a curled leaf with dew on it, a bit of scrutiny unveils the butterfly, much like the image of this moth -- head, antennae, forelegs, wings, abdomen. Though each species of pupa has its own distinct shape, the same body parts are always outlined on it.
28 September 2009: Since my last entry I've prepared for a huge trip, taken in a week's worth of wedding festivities in Canada, imported a used car, returned home, and cleaned up much of the aftermath. At last, today, I found a little time to snip my remaining cocoons.
I couldn't remember how I snipped the previous cocoon, so today's effort was made possible with a suture removal scissors that I happened to have. I was very careful to force the point as far away from the pupae as possible. Thankfully, no damage was done.
The cocoons are interesting three layer structures. The layers can be seen quite well in the photo: outer cover, inner fluff padding, innermost hard, pod-like structure that snugly houses the pupa.
My two remaining pupae were both males; both were smaller than the female pupa. She's on the left.
One cocoon appeared to have its inner and outer valves on opposite ends. We'll find out next summer. I've since restored all my bugs to their respective cocoons. Soon they'll go in cold storage for the winter.
I found some videos on YouTube that were made by a moth raiser who cuts away some of the cocoon, then pins it to a board with the valve facing up so that the emerging bug can crawl out onto a something that it can easily cling to for wing drying. This person then puts a time lapse video camera on a bunch of these cocoons, so that the eclosing process can be readily seen, as the moth still goes for the valve, even with a different hole available to crawl through. It's all about bug programming!
So anyway, I figure to cut more cocoon away next spring, so I too can enjoy the show. Then, hopefully, I'll be around at the right moment.
Don't know if caterpillar size has anything to do with gender, though we know that female moths are larger than males. Red Knobs grew to be my biggest/longest caterpillar. She wasn't significantly larger, but the difference was measureable. One other caterpillar was almost as big. However, she turned out to be the only female.
1 October 2009: I refrigerated my bugs today. The weather had turned frosty and nights are cold, so I figured it was time. They are in a ziplock bag in a crisper. My husband cautioned me that the basement refrigerator tends to get pretty cold, so I also put the bag in a small cardboard box. Had I not opened the cocoons, I probably wouldn't have done this.
Periodically I will check on the bugs. A dead pupa loses its weightiness so that the cocoon feels feather-light. Of course, I can also simply take the bugs out of their cocoons to check for life. Anyway, that's for a later time. Now we face a long winter. May seems ages away.
24 November 2009: I checked my bugs today. I took them out of the refrigerator and then out of everything else, including their cocoons. Everyone is alive and well. Each one wriggled for me after my hand had warmed them up a bit. I kept them out only briefly, and then packaged them all up and put them back in their cold storage. All is well in bugland.
5 February 2010: I took the bugs out of the frig tonight to check their health. They are doing very well. Upon warming up a bit, they became wriggly. They are now back in cold storage.
I have thought about selling one of the males, but that would pose certain problems. The cocoons of the two males are fused together. I could try switching a male with the female's cocoon, but she is bigger than the males and so is her cocoon. Also, I've slit all the cocoons, so if a buyer would want a "pristine" cocoon, it ain't gonna happen. Personally, I think the slit is great, as it allows me access to the pupa within, and will also allow me to observe the eclosing process, as I was careful to leave the valve end undamaged. The moth will go for the valve; that's its programming.
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