Monthly Archives: August 2011
Back from Arizona
Whew… what a trip! I learned a lot at the Lep Course and had a ton of fun.
I’ll write of our adventures and put up photos as soon as I can get myself organized.
In other news, the last of my first brood of Acronicta have pupated… but I got a few hundred eggs/hatchlings in the mail this week (and more are on the way!)… so it looks like the Arizona trip was my only “break” from caterpillar rearing. These guys will keep me busy well into the semester. Which I’m trying to not think about too much – I’m taking Systematics, Evolutionary Developmental Biology, a systematics seminar, and I am teaching 4 lab sections of intro bio for non-majors. And of course, starting more serious analysis of specimens for my research.
I’m not satisfied unless I have a million things to do and not enough time to do them all!
Birthday Caterpillar Fun
I am 23 today!
Today is caterpillar day at the Lep course, with lectures in the morning and collecting scheduled for most of the afternoon. Then later tonight we’re switching gears and learning adult moth genitalic dissections.
Should be a fun day 🙂
Arizona
I forgot to mention… I’ll be in Arizona for the next week! I actually just arrived a few hours ago.
I’m here at the Southwestern Research Station (SWRS), run by the American Museum of Natural History, taking a Lepidoptera field/training course. Since the internet connection here is so slow and spotty, I will provide links and photos when I return. I will try to update with little stories if I can while I’m here, and will hopefully have time to flesh them out later.
This is where I came with my advisor last summer, to help him with his research and just explore. Now I’m prepared to tackle the wilderness and learn a lot about moths.
I already caught one tiny vinegaroon while wandering around flipping logs near the creek. I can’t help myself.
Stanley is back!
Stanley is my pet vinegaroon (Mastigoproctus giganteus). I brought him (sex yet to be accurately determined, was captured as a juvenile) home from my trip to Arizona last August, and for a while he was a wonderful companion. He would dig new tunnels almost every day, and diligently ate his crickets. But about five months ago, he dug a tunnel without an exit. He stayed in that tunnel without once leaving for water or food. I could usually see him from the bottom and could see him move, so I knew he wasn’t dead. I have a feeling this move coincided with the “dry season” in Arizona, and he waited to emerge until the “wet season” had begun. I wonder how he could tell all the way from CT!
I knew he had emerged when it looked as though the entire tank had been turned upside down. Piles of dirt everywhere, water dish filled in (he loves to do that).
He’s incredibly skinny now, but quickly catching crickets, as you can see above. I’m hoping he’ll soon be plump and energetic as usual.
Wardrobe change
Acronicta laetifica
5th instar
6th instar (same individual)
I’m not sure why this species goes through such a drastic change –Â it keeps roughly the same head capsule patterns and dorsal stripe, but the colors are all switched around. Perhaps in the wild this is associated with a change in behavior? The greener, earlier form is more likely to sit on leaves, perhaps the brown/gray form is a bark rester? This is tough to observe in the lab because they are just kept in vials with leaves. I did find one large A. laetifica (brown/gray form, last instar) in the wild, but it was from beating a tree, so I don’t know how it was resting naturally. Anyone have other insights?
Aw, poop
Acronicta funeralis – 3rd instar.
I’ve got a bunch of these caterpillars, raised from eggs. They are all thriving, and looking like adorable little lumps of bird poop at this point. As you can imagine, this is a great strategy for not getting eaten. Who wants to bother with a lump of unappetizing bird poop? It even has a lump of white “uric acid” as the last few abdominal segments.
They are going to undergo an amazing transformation soon into a completely different set of colors/patterns, I’m pretty excited! After a while they get bored with the bird poop mimic strategy, and take on another form. Stay tuned, it should happen within a week or two.
Acronicta americana – pupation
A couple of weeks ago my Acronicta americana caterpillars decided it was time to pupate. I provided them with some soft wood, and they dug right in!
They were mostly white or only lightly yellow-tinged before they started, but once they began digging they darkened up. Their hairs and underlying body color all turned a brownish yellow in order to blend in with the wood a little better.
Most Acronicta caterpillars burrow into wood in some fashion in order to pupate. Some of these Acronicta americana made tunnels all the way in, some made troughs that they covered with bits of wood, and some were lazy and made their cocoon on top of the bark.
Here you can see some of the silk and bits of wood one caterpillar used to protect itself.
Every day I check the container excitedly, I cannot wait to get some adults! I had 10 A. americana caterpillars pupate, so I should have a pretty good series once they all emerge.
Attack
Some of my caterpillars are getting big enough to give me a good bite.
Of course, this is something you don’t really expect from a cute cuddly caterpillar. They just eat leaves, right? They don’t try to actually attack you, right?
So much for that.
Look at those jaws! My Acronicta afflicta caterpillars are getting quite large now, and a bit grumpy. I went to clean this guys’ container the other day, and he reared up and bit me! Sometimes they’ll thrash and pretend to bite, but now they can actually dig in.
They usually use those jaws for chewing tough leaves, like this. I was trying to photograph this one when it decided having a snack was better than posing for the camera.
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