Monthly Archives: June 2013
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.
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:
I hadn’t seen a spot pattern quite like that before (the things on top are the mother’s scales).
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.
Texas Days 2/3 – Fort Davis
Oh right, Texas! It already feels like so long ago, we’ve been so busy here in the lab.
Our second stop in Texas was Davis Mountains State Park, in Fort Davis. It was another long drive across flat, desert-like land. We saw several hundred (thousand?) wind mills, which created a very eerie landscape. Fort Davis provided an emotional refuge of mountains and trees. We arrived late afternoon, and promptly went for a hike to stretch our legs.
Everyone we had talked to said that west Texas was experiencing a several-year-long drought. When we arrived at the park, it became quite clear they were telling the truth. Trees were clinging to old, tough leaves. Grasses were brown and crunchy underfoot. Wildlife seemed scarce. Aside from a couple whiptail lizards, a ground snake, and some unruly javelinas, the landscape seemed eerily deserted.
By the time we set up camp and settled in it was getting dark, so we set up a blacklight. Not much came in other than micro-moths and midges. Disappointed, we hoped the next day would be more fruitful.
In the morning we got up early for some caterpillar hunting. Well, I went for a run and a workout first, but then we armed ourselves with beating sheets and sticks and began wandering around the campground. There were only a few other people in the park, so the park staff didn’t mind.
Abilene sure was lush in comparison! But we did not give up hope, and searched as many branches as we could reach. Each tap of a tree branch released plumes of dust, pollen, and dead leaves. Surprisingly, we found a bunch of geometrid caterpillars. I wonder why they were the most abundant?
After an hour of not-very-productive searching, Ben shouted “Brigette, I have a present for you!”. Sure enough it was a little Acronicta caterpillar on an Emory oak tree! Despite our renewed enthusiasm and re-doubled efforts, we did not find any more Acronicta in the park. This little caterpillar grew up to be quite interesting – it’s the one featured in this post.
After a quick lunch (which became our classic: gluten free wrap with sliced turkey and a dill pickle) we drove a few miles down the road to the Chihuahuan Desert Nature Center. A place so wonderful it deserves its own post, coming soon!
There are caterpillars called “slug caterpillars” due to their, well, slug-like appearance. They are the Limacodidae, and they are some of the most beautiful and bizarre caterpillars out there.
Not to be outdone, there are a few species in the genus I’m studying, Acronicta, which resemble the infamous slug caterpillars. Blobby green things that hide their heads while at rest.
These caterpillars were raised from eggs laid by a few females I captured in Boerne, Texas. I am uncertain whether they are Acronicta vinnula (common throughout the eastern US) or Acronicta lepetita (native to southern Texas, and so closely resembles A. vinnula that I am unsure how to tell them apart). As far as I can tell, the caterpillars are identical to the A. vinnula I have raised in the past.
It appears that no-one has raised A. lepetita before. Someone please correct me if I am wrong.
The most information I can find is that “the larvae feed on various plants”. Thanks Wikipedia, that’s quite helpful.
What might be more helpful is a look at the adult. Here is one of the mothers.
I’ll throw this one out to you again. What do you think?
My caterpillar season is starting to gain momentum. Caterpillars are hatching, eating, growing, pooping. Getting eggs in the mail from collaborators. Running around campus to collect plants. And some of the caterpillars from my Texas trip are approaching pupation.
I was somewhat in denial of this fact until I saw the size of this guy.
That is a FAT caterpillar! I’d never seen an Acronicta caterpillar look quite so much like it’s going to pop. It also wasn’t in a terribly good mood.
Today I found out why. I checked on Mr. Angry Sausage Caterpillar and it looked a bit… different.
The bright reddish orange coloration and jet-black head were an impressive change. I have only seen this sort of change in one other species, Acronicta lobeliae, which also gains a black head and darker coloration before digging a pupal chamber.
I realized this caterpillar had stopped feeding and was ready to pupate. Poor thing was waiting for the right substrate!
I put a piece of soft, spongy wood into the container, since most Acronicta pupate in wood. It found the wood within minutes, and within an hour had chewed a tunnel into the wood. It’s currently sealed up, where it will remain for a couple months until it is ready to emerge as an adult.
I’m still not entirely sure which species this is. It was collected in Fort Davis, Texas. My guesses are either A. afflicta or A. brumosa. What do you think?
Not a caterpillar
Yesterday someone knocked on my office door. I was momentarily annoyed at being interrupted. But when I opened the door, I saw a man holding a glass jar with parchment paper rubber-banded over the top. Jars with make-shift lids are always a good sign.
He said he was in the area visiting colleagues at UConn, and he noticed my door had bugs on it, so would I be interested in the biggest spider he’s ever seen?
Why yes. Yes I would.
Say hello to Miss Dolomedes tenebrosus, the fishing spider. She looks big and healthy, perhaps preparing to lay an egg sac (which she will then carry with her mouth).
I tried to take a few photos of her with my new camera rig, but she was not very cooperative. Even after a cool-down in the fridge, she was incredibly feisty. Here are a couple shots I managed to snag.
I don’t really have a reason for posting these photos… but… do you need a reason to share a pretty spider? I think not.
I love macro photography – who doesn’t? To take a tiny, seemingly insignificant insect and to blow it up to the size of a cat is exhilarating. There are many wonderful macro photographers out there (check out the list of links to the right), whose photographs I drool over every day. However whenever they mention the equipment used, a pit grows in my stomach. It’s all so expensive! So many lenses and flashes and rigs and fancy things I have never heard of. How is a poor/cheap grad student supposed to get into macro photography without a huge monetary investment? How can I ever dream of improving my “take 100 pictures and hope one of them turns out sort-of-ok” strategy?
For a long time I have felt relegated to various point-and-shoot cameras. I had a camera in high school I was able to attach a little macro lens to, but that camera became bulky and obsolete. I considered second hand cameras, but had no idea where to even start.
Fast forward to last year. I was gifted an old Nikon DSLR camera body by a colleague. I was excited, but quickly realized that without flashes (expensive) and macro lenses (expensive) I wasn’t going to get photos any better than with my point-and-shoot. So it sat in my desk drawer.
Fast forward again to this April. One of the invited speakers to the Connecticut Entomological Society meeting was Art Vaughan, a macro photographer. However he doesn’t have the same kind of equipment as other photographers. He specializes in building his own rigs to take advantage of the pop-up flash present on every camera. His rigs include clothespins, screws, bendable book-lights, aluminum foil, and pieces of metal. He finds lenses in garage sale projectors and cameras, and attaches them with bungee cords. I thought – hey, that sounds like something I could do!
To see what he can do with these rigs, check out his flickr page here:
With the help of a colleague (who has the power tools needed to cut and shape metal) I have assembled my own camera rig.
The goal of this rig is to redirect the light from the pop-up flash to the two foil cards. This causes the light to act like two separate flashes, resulting in more even lighting across the subject. I finished putting the rig together yesterday, so I tested it out on some caterpillars.
Not bad, eh?
I’m pretty excited that I no longer have to rely on the availability of the “lab camera” to photograph my caterpillars. My rig is a bit bulky and awkward at times, but considering it cost me $75 (for the macro lens, adapter, and two book lights), it’s worth a bit of trouble.
If you want to learn how to build your own, Art is amazing and would love to help. You can email him at: thylacine1936[at]verizon.net
Light trap on-the-go
One way to collect moths is with a light trap. They consist of a bucket, a funnel, a blacklight, and some barriers that the moths run into. They typically look something like this:
The goal is for the moths to be attracted to the blacklight, hit one of the metal plates, and tumble through a funnel into the bucket. There can either be a killing agent in the bucket, or the moths can be captured alive (though you’ll want to have some egg cartons for the moths to climb on so they don’t destroy each other by fluttering). This type of collecting is good for ecological studies, trying to find a rare species, or to attract something that only flies late at night (and you are not willing to stay out that late).
I thought a light trap would be useful for my Texas trip, but there was no way we wanted to bring another large box or suitcase. We thought about mailing a trap down to a collaborator, but that would be fairly expensive. Instead we deconstructed a non-functioning light trap we found in a back room, and bought some supplies when we arrived.
We brought the acrylic plates, hooks, a funnel, and a blacklight. At Walmart we bought a bucket and a pool noodle, and we were in business.
The purpose of the pool noodle was to ensure a tight seal between the funnel and the bucket, so nothing could escape. The battery we bought fit perfectly into a beer cooler, so the whole set up became quite portable and easy to take apart. Success!
With access to the right starting materials (acrylic panels, springs and hooks, a funnel and a blacklight) I would do this again in a heartbeat for a long collecting trip. Those all fit easily into a suitcase. At the end we recycled the bucket, left the battery with a collaborator (can’t fly with a battery, sadly), and took the rest of the materials home.
Have you created your own blacklight trap? Do you have a design that is easy to take apart and transport? I’d love to get more ideas for next time.
Texas Day 1: Abilene
To keep costs down, Ben and I decided to camp for the entirety of our Texas trip (aside from two nights at a colleague’s house). This made our trip feel even more adventurous. We’re used to showing up to a research station with dorms, a kitchen, and a laboratory with supplies. This trip was quite different! We brought my tent, and bought some cheap sleeping pads and sleeping bags at Walmart when we arrived. We also bought some batteries to run our lights, and parts to build a light trap.
We arrived in Dallas, loaded up the car with supplies and food, and drove out to Abilene State Park. I truly did not believe we would fit all of our supplies into a compact rental car, but we did.
The area seemed scrubby, a little dry, and an odd mix of forest, scrub, and almost-desert habitat. The air was hot and humid. There were only a few other people in the campground, as this is not an ideal time to be camping in Texas. As soon as the tent was set up, we set off to explore.
We saw a few caterpillars just by walking around – like this little notodontid.
Our daytime caterpillar search wasn’t terribly fruitful though, so we held out hope for the night. We weren’t too impressed with what the light brought in (our campsite had electricity!), but we did have fun (and strained our necks) looking for caterpillars. We were spooked by a few raccoons, but otherwise didn’t run into any trouble.
Our first big find turned out to be an Acronicta caterpillar! I spotted it sitting on a branch just above my head. I instantly recognized its fuzzy gray body as belonging to Acronicta lobeliae.
But I wasn’t prepared for what happened next. After taking this photo, I reached toward the caterpillar to pick it up. It instinctively dropped to the ground, where it landed directly into an antlion pit! It thrashed around as the antlion tried dragging it under the sand. I quickly scooped up the caterpillar but it appeared paralyzed or dead – frozen into a half curled position.
I kept the poor guy anyway, and within about an hour it was back to normal. Whew!
Here are some other pretty caterpillars we came across:
We weren’t blown away by our first night, but I was quite happy to have an Acronicta caterpillar in hand. We stayed one night, and the next day continued our journey west, to Fort Davis.
Ben and I are back from our Texas adventure – and what an adventure it was.
I have lot of photos to sort and lots of stories to tell. Hopefully I’ll get Ben to help with some of the posts.
Summary: we didn’t get the rare species I was looking for, but we got lots of other goodies and met some amazing people.
I also have some grand plans to separate my caterpillar life from my sewing/weirdbuglady life. I want to make separate flickr accounts, deviantart accounts, twitter, etc. I feel like I should make my presence less of a mish-mash of everything in my life, and organize into the two main camps: research vs. art. There will be overlap at times, sure, but I’m going to try my best. So… we’ll see how that goes.
I’m going blacklighting and gas-station hopping tonight, so I’ll get started with Texas posts tomorrow!