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Fuzzy babies

Lots of fuzzy baby caterpillars here in the lab. Right now these two species look pretty similar, but the differences will start accumulating in the next few instars. Currently they are less than a week old. The first two photos are the babies from this post!

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Acronicta hastulifera, second instar

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Acronicta hastulifera, second instars

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Acronicta americana, second instars (and molting into third)

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Babies everywhere

300. That is how many little Acronicta hastulifera caterpillars hatched this weekend (click here to see the mother). Actually, there were probably more than 300, but I stopped counting.

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Developing eggs, two days before hatching.

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Lots of little first instars.

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As you can see by the giant holes in some eggs, many of them ate their egg-shells before wandering off.

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Babies on their host plant, alder (Alnus). Exploring a bit before settling down to eat.

The big hatching event happened on Sunday. It’s a good thing I came into the lab, because by Monday they would have been dead without food. I then became incredibly nervous that I might not have given them the right host plant, but they have been producing a large amount of frass (poop). Hurray! I get so protective of my caterpillar babies. This is what they look like today:

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Frass machines.

They are going to become wonderfully fuzzy caterpillars as they grow. I can’t wait!

Happy egg dance

On Saturday night I joined a bunch of entomologists for the 5th Annual Moth Ball in Massachusetts. Lights, sheets, cameras, beer, hotdogs, snacks, and tents for staying overnight. What could be better?

I was also on a mission. One species my advisor has been telling me I need to get ahold of is Acronicta hastulifera. As an adult it is nearly indistinguishable from Acronicta dactylina, though their caterpillars are quite different. The best way to make an ID, then, would be to catch a caterpillar and rear it to adulthood, or to get eggs from a female and raise the caterpillars. This is not always easy to do.

I found a few Acronicta females at the moth ball, nothing terribly exciting. Though it wasn’t long before a friend of mine approached with the grand prize in his hands (from a nearby sheet): Acronicta hastulifera. A big fat female! Success! The rest of the night paled in comparison to that moment.

When I awoke in my tent the next morning (after only a few hours of sleep), the first thing I did was check her container for eggs. About a dozen big green eggs dotted the sides of the vial. Woohoo! Last night I set her up in a larger container, and she really let loose. I estimate 200+ eggs.

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Momma moth and some of her eggs.

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So many eggs! My favorite colors, too!

At first I was a little worried that all of the eggs were remaining green. With other species that is sometimes a sign they are infertile. But once they gain some spots and other coloration, you know the larva is developing inside. Like this:

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A close-up, taken with my little Canon Powershot through a dissecting scope eyepiece.

I hadn’t seen a spot pattern quite like that before (the things on top are the mother’s scales).

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Some of the freshly laid eggs, before gaining their spots.

Now I must be patient and wait for them to hatch. Most Acronicta eggs take five or six days. I’ll be ready with some Alder (their favorite food), and my camera to get pics of the little ones.

Ryerson Lab

Functional Morphology, Sensory Biology, Behavior, Biomechanics

I spell it nature

Trying to make sense of the world through science and language.