Cecropia Moth Project, Day 10

2nd instar caterpillar above two 1st instar caterpillars

Lots of updates to share on the 10th day of rearing.

Unfortunately, the small caterpillar that was having trouble clinging to leaves has died. There are now 14 caterpillars. This is still too many for us to feed once they get large, so we are going to have to figure out how to let some people go.

We changed the habitat as a result of problems we had with the previous setup. We got rid of the stick that we were using because it seemed to be housing an insect that was dropping eggs, and it also wasn't helping to keep the maple leaves fresh. We purchased water tubes used by florists, and made a simple stand out of a folded cardboard beer box (see photo below).  By keeping the maple leaf stems submerged in water, the leaves are staying fresh.

Aerial view of new set up

Water tubes, 5 cents each at florist

The big news: yesterday one of the caterpillars entered the 2nd instar stage. We were watching the caterpillars, staring really, then left the room for only a few minutes. When we came back, the caterpillar had shed its black skin and was a bright yellow color. In the opening photo, you can see the shed black skin bunched up near its rear - the caterpillars emerge out of their skin head first. It also appears that the shiny tops of their heads pop off when they do. You can see the caterpillar's little hat in the opening photo, just below the curve of its body.  Other sources have suggested that the caterpillars eat their old skin. We didn't see this happen, but the old skin is now gone (though the hat remains).

Minutes later, we witnessed a few of the other caterpillars stretching and writhing around. We were certain that we were about to witness another caterpillar molt. After twenty minutes or so nothing had happened, so we left them alone. Today they all remain in the 1st instar stage. Some of these caterpillars are getting very long and fat, so we imagine they'll be molting any day now.

Some remaining 1st instar caterpillars, looking terribly obese

Cecropia Moth Project, Day 7

Behold - the yellowing of the Cecropia caterpillar

Cecpropia caterpillars gathered together 

The Cecropia caterpillars are now seven days old. They have been splitting their time between resting and eating, and we see huge chunks of maple leaf being devoured. 

We've noticed that some of the caterpillars seem to be more social than others, gathering closely together on one leaf to eat and rest.

While most of the caterpillars are growing and taking on strong yellow highlights (almost time for the 2nd instar stage), one little guy seems to be struggling. He has fallen off of leaves several times, and he's much smaller than the others.

Another issue we're having is the stick that we placed in the habitat. We noticed a small hole near the end of it, and it appears that some kind of woodboring insect is living inside. Several inches down from this hole we found some miniscule oblong egg-type things that had dropped from another opening. We are going to remove the stick and the eggs, and also stop using the dirt. It seemed like a good idea, but in both cases - the dirt and the stick - there may be something living inside that could kill the caterpillars or spread disease.

Cecropia caterpillar, taking on yellow highlights

Cecropia Moth Project, Day 4

We were able to find a new habitat for the 1st instar caterpillars, so now there will be plenty of space to move around when they get large (Cecropia caterpillars can grow to be the size of a human finger).

We filled the fish tank with dirt to combat the frass issue. It's either regular frass cleanings or sporadic dirt shiftings, so we went with the dirt shiftings. We also put a branch inside and lined it with the maple leaves. We're trying our best to simulate a natural environment. We included another wet paper towel at the bottom of the tank to keep things moist.

Today consisted of a lot of lounging around for the caterpillars followed by some gorging. We noticed that a few are starting to take on a yellow color, which may mean they are getting ready to ecdyse into the 2nd instar stage. They are now four days old.

Cecropia Moth Project, Days 1 and 2

Cecropia caterpillar, 1/4"

Once the eggs hatched we found fifteen 1st instar caterpillars, and we were eager to get food to feed them. Normally, the eggs are laid on the host plant and the caterpillars feed on that. We read that the host plant for Cecropia moths is the wild cherry tree, but we could not locate any in our area. The caterpillars will also feed on ash, birch, box elder, alder, elm, maple, poplar, plum, willow, apple, and lilac leaves.

Initially we could not find any of these trees. It could be because most of these trees are deciduous, and do not have any leaves this time of year. We tried feeding the caterpillars a number of other leaves including eucalyptus, asian pear, blueberry plant, blackberry plant, lemon tree, hawthorne, and countless others that we weren't able to identify. With each new leaf that was added to the container the babies became active and began to explore, but they quickly lost interest. The first bites we saw were on the eucalyptus leaf, but it seemed they were sampling rather than actually feeding. In all cases they abandoned the new leaves and returned to climbing up the sides of the container, eventually congregating at the top.

Almost 48 hours after the hatch, the caterpillars still hadn't eaten. We became nervous thinking that we might not find any suitable food. We drove around and finally located a maple (one of the trees listed as part of their diet). We attached the leaves near the top of the container, hoping that since they head to the top anyway they might incidentally land on the leaves. We also added a moistened paper towel to the bottom of the container, as we read that they will not feed if their environment is too cold or too dry.

When we woke up this morning we found that the caterpillars had eaten the maple. There is also a noticeable amount of frass (caterpillar feces) on the bottom of the container. Very exciting. Today we will try to find a larger container and collect more maple leaves. 

Cecropria Moth Project

On February 2, Oliver found this moth clinging to the side of a building at Calamigos Ranch in Malibu. He brought it home because he thought I would like it (I did). We identified it as a Cecropia Moth (Hyalophora cecropia), North America's largest moth. This particular species has an adult lifespan of 7-10 days. Flying only to mate and lay eggs, it does not even have a mouth.

Oliver placed the moth in a plastic container for transport. These moths release eggs when they are about to die, and we found a number of eggs stuck to the sides and bottom of the container when Oliver returned home. The moth died about an hour later.

We kept the eggs in a tightly sealed container punctured with air holes, and they sat unattended in a shady corner of our house for sixteen days before hatching on February 18.

Cecropia eggs