Monthly Archives: July 2013
My little tigers
My supposed Acronicta hastulifera caterpillars are growing up. And growing into very convincing A. dactylina caterpillars.
A. hastulifera have frosted hairs (hence the common name “The Frosted Dagger”) which these caterpillars do not have. A. dactylina caterpillars have fluffy orange/brown bands, while A. hastulifera have more diffuse orange and gray hairs. They are trickier to distinguish in early instars (see these posts for pics), but at this point, I’m convinced this species is A. dactylina.
Goes to show just how difficult it is to tell the adults apart, that both Dave and I misidentified the mother moth.
One species on my “must rear because it is so totally awesome” list is Acronicta radcliffei. It is a very close mimic of one or more species in the genus Datana (family Notodontidae), and it appears to be aposematic. Such stark yellow, red, and black markings typically advertise toxicity. This month I got my wish!
I went caterpillar collecting with another lab at Cockaponset state forest two weeks ago. We were all helping to hunt for the various caterpillar species we all are studying. We knew A. radcliffei, a relatively rare species, had been found in the area before. I wasn’t sure how optimistic to be, but sure enough, a group from the other lab snagged two of them! They were both still in their green and red, early instar color form – but by the next day they had both molted into their final instar, colorful vestments.
One of them mysteriously died while I was on my trip to Colorado, but the other thrived.
This caterpillar pupated before my experimental protocol (for testing palatability) was finalized, so I will have to wait until later in the summer or next year to test whether this species is truly chemically protected. I wonder if those colors are a true advertisement, or if it is bluffing?
For comparison, here is a Datana caterpillar, thought to be noxious to predators.
I know, I haven’t even finished my stories about the Texas trip, and now I’ve gone to Colorado for more moth and caterpillar wrangling! All the pictures and stories will keep me busy for a while. Recently got home after a week of beautiful mountain views, black lighting, caterpillar hunting, rainstorms, great people, visiting collections, and spending time with my aunt (who lives in Boulder) as an added bonus. My mom accompanied me for part of the trip, and was a great sport about helping me find collecting locations.
I started by flying into Denver late Thursday night (a trip fraught with nearly missing flights, booking the wrong hotel, and a long but interesting cab ride). I met up with my advisor in the morning and we hashed out our plans. Nearly everything had to be improvised due to the weather and who could meet with us. Before I had started grad school this approach would have sent me into a panic attack, but by now the fly-by-the-seat-of-your-pants-approach (championed by both my advisor and my boyfriend) is standard. We visited several collaborators, hunted for caterpillars, and set up sheets at night before parting ways – I stayed a few extra days to be with my family.
Here are some highlights from the trip. You will notice a severe lack of caterpillars – there were hardly any to be found! Not sure if it was the weather or the time of year?
I had a wonderful time in Colorado, and really hope it’s not too long before I can visit again. Besides, next time I need to get some female Acronicta and some eggs!
Time for a change of clothes
This great video was shot by my friend Sam Jaffe, expert caterpillar wrangler. He is spending his summer bringing caterpillars to farmers’ markets and science museums as entomology outreach for children. He specializes in the big ones, like this Hyalophora cecropia caterpillar. He managed to catch it as it was molting into the next instar:
He’s also an indefatigable moth hunter and finder-of-caterpillars-on-the-undersides-of-leaves. If you are in the northeast and want to see one of his shows, check out his facebook page: The Caterpillar Lab.
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!
I love this caterpillar. I wish that more than one had survived from the eggs the mother laid, so I could preserve one as a voucher. I was considering preserving this one, but today I noticed it was beginning to pupate in the bottom of its container. I guess I will wait for it to emerge as an adult.
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.
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:
They are going to become wonderfully fuzzy caterpillars as they grow. I can’t wait!
Green and orange and purple
Here are some more fun photos of Acronicta lepetita from Texas. Some of them turn orange during their final instar, some stay green, some even turn purple-ish. Luckily this species is quite sedentary, so it is relatively easy to photograph. This first shot is one of my favorites:
Many caterpillars are known to turn purple-ish, red-ish, or pink-ish just before pupation. However this orange color change happens while the caterpillar is still feeding, sometimes up to a week before pupation. It happens in Acronicta vinnula as well. I wonder why a caterpillar would want to be orange while still feeding on green vegetation?