Category Archives: Lepidoptera
Well, we’re off! Ben and I are going to spend 10 days traveling across Texas. We’re armed with several permits (for Big Bend National Park, Texas State Parks, and one National Forest), several suitcases full of vials and lights and other collecting equipment, camping gear, and enough homemade beef jerky to sustain us for several days if we get lost in the wilderness.
Our main target is the species Acronicta valliscola, a species only known from Big Bend. I want to snag it for DNA and hopefully raise the caterpillars, since they have never been seen before! It’s the right time of year and right weather, so hopefully we stand a good chance.
When I return, the beginning of intensive research (and blogging) season will begin. Lots of pictures, lots of caterpillars, lots of discoveries.
While I’m gone the lab will be tended by a few faithful labmates, and my bunnies will be tended by my wonderful boyfriend. So now all I have left to do is… get on a plane before I think of another thing to cram into one of my bursting suitcases.
Wish us luck!
I got permission to do some of my research! Woohoo!
Specifically, I will be collecting in Big Bend National Park, Texas, in a couple weeks. There is one Acronicta species, Acronicta valliscola, which was discovered within the park and has only been found there. All of the specimens I have seen in collections (and there are only a few) have been 30+ years old. So in order to get DNA for my phylogeny, it’s off to Texas I go. The time of year is right, the plane tickets have been purchased, and we’re starting to gather our field gear (trying to figure out how to carry a tent, sleeping bags, UV lights, caterpillar jars, etc).
I will be going with a student who started in our lab as an undergraduate helper, then stayed a year to work for us in the lab, and now he is accepted to be a masters student in the fall. He knows his way around some caterpillar frass, let me tell ya. We will be traveling to Big Bend as well as some other locations in south-central Texas to collect moths and caterpillars for my project.
If anyone knows of good collecting spots in south-west or south-central Texas, please share! Even better if you live in the area and would be willing to host a couple of caterpillar-crazy entomology students for a night.
I’m sure my excitement won’t fully materialize until we arrive. For now I mostly feel relief that at least part of my project is going as planned.
Joe Acronicta had had enough of us poking and prodding him, and decided to pupate.
I know that most Acronicta species pupate by tunneling into soft, dead wood. But usually this is a shallow groove, covered by bits of wood and silk. Sometimes they burrow in deeper, but you can see the hole behind them.
Joe decided to be a bit like some other Acronictines (species in different genera, but still closely related to Acronicta). Genera like Comachara, Polygrammate, and Harrisimemna all dig deep tunnels into wood. Then they crawl out and back into the tunnel rear-end first, sealing up the entrance with silk and bits of wood.
That’s exactly what Joe did.
The cleverly disguised entrance.
I’m not sure how long it will be before he emerges, maybe a few weeks or months? When caterpillars pupate early in the season, it usually (but not always) means they will emerge in time to start another brood before cold weather arrives. If they pupate late in the season, they will usually (but not always) overwinter as a pupa.
While we are pretty sure that we have these caterpillars matched up with the correct adult, we are excited to have an adult emerge so we are 100% sure. I’ll post pictures when Joe makes his appearance as a moth!
We recently received a new friend from Texas – nicknamed “Joe Acronicta” by the collaborator who sent him to us.
This is one of my favorite species – Acronicta atristrigatus, also known as the “Paddlemaster”. I bet you can guess why.
What we’re all wondering, though, is what those paddles are for. They appear on several Acronicta species, but in different arrangements. Some only have them in place of the dorsal setae, while others are nearly covered in paddles. I have a feeling they are used to thwart parasitoids which may try to land on the caterpillar to lay their eggs. Many species of flies and wasps see caterpillars as big tasty meals for their offspring.
I imagine all those hairs would make it difficult for a parasitoid to land. And if it does, the caterpillar will surely notice.
These guys also have some interesting defensive behaviors.
Don’t worry, I did not hurt the caterpillar! Like most Acronicta species, it starts with a bite (or attempted bite). But instead of simply returning to its perch, the caterpillar begins to sway side to side. We are all curious as to whether this serves to deter birds, or parasitoids, or perhaps the caterpillar is trying to sway gently like a tree branch?
What do you think?
It’s springtime, and that means the moths in the lab are emerging from their cocoons. Since it is warmer here in the lab, they tend to emerge a few weeks earlier than they would in the wild. This means we get a head-start on pinning and labeling the moths before the field season gets underway.
One wall of our “rearing room”
It is bittersweet, sometimes, when I meet an adult moth I’ve raised from an egg. Knowing that it will be added to my collection as a specimen. Advancing science, but putting an end to a small, fuzzy life. It doesn’t help that I get quite attached to my caterpillars.
But in many ways I embrace this aspect of my work, as the act of pinning and spreading a moth involves considerable skill, practice, and artistry. I am also a firm believer in the importance of scientific specimen collections. Monday mornings are currently my favorite part of the week because that is when I work in UConn’s biological collections, helping to curate the moths. Each specimen has a history and tells a story.
A freshly emerged adult moth
Some moths on the spreading board
With the emergence of the moths comes the emergence of field gear and enthusiasm. The caterpillar lab can be a dull place during the winter. But this spring/summer promises to be full of adventure, misadventure, and insects. We are starting to receive caterpillars in the mail from collaborators in warmer climates. Moths are fluttering around porch lights at night. Collecting trips are being planned all around the country. I will be breaking out my own collecting lights within the next couple weeks.
For the time being, though, my main duty is pinning my adult moths as they emerge. If you would like to learn more about this task – my friend and I are currently creating an instructional screencast on how to pin a moth – I will post it as soon as it is finished.
I thought it would just be a cute addition to my collection of insect books, but it has really wonderful illustrations featuring a wide variety of behaviors and natural history. The author and illustrator really knew their caterpillars. The caterpillars are all based on real species found in North America. The illustrations feature eggs, first instars, morphological changes, defensive behaviors, molted skins, feeding behaviors – even frass flinging!
That caterpillar in the middle is clinging to the stem face down, and has twisted its rear end over its back in order to shoot its poop. This book was definitely written by an observant nature lover.
I’m calling this my new favorite book, and highly recommend it for anyone who likes caterpillars. I think the target age is about 5 or 6 years old… but… no one will judge you.
Gladys Conklin wrote a variety of children’s books on insects and other animals. Some titles include “I Watch Flies”, “When Insects are Babies”, and “I Caught a Lizard”. I want to buy them all!
My caterpillar colleage Sam Jaffe has created a kickstarter project – an ambitious plan to create a series of programs and events using live caterpillars for science education outreach. If he’s funded, he’ll do it all this summer!
Sam is an amazing photographer and great caterpillar wrangler. Please consider donating to his cause, or at least check out his work – his photos make caterpillars look nearly as cuddly as the plushies I sew!
This is depressing.
As some of you know, I have a sewing business on the side. I haven’t made anything in a few weeks, though, because grad school tends to get in the way of hobbies. But I feel inspired to make some caterpillar plushies this weekend. Stay tuned.
While at the Smithsonian National Museum of Natural History, (see previous posts here and here) I did manage to tear myself away from the collections long enough to browse some of the public exhibits. I did not go into the butterfly house (didn’t have my wallet with me, you have to pay to enter), but I did see some caterpillars!
There was a whole section of the museum devoted to insects and invertebrates, with many live organisms on display. There were a lot of the usual suspects (mantids, tarantulas, roaches), but they also had some hornworms (Manduca sexta). There was a display with a multitude of pupae, a few caterpillars, and one freshly emerged adult. It was being nibbled by a persistent, and apparently violent, caterpillar. I do not know why.
There was also a display where you could see some pupae of various species hanging – waiting for their chance to emerge and become part of the butterfly house. There were not just butterflies, though. I could see many moth cocoons, the fuzzier looking ones at the bottom.
And I really liked the displays! The blatant emphasis on evolution in almost every single display and description is refreshing (the hall of human origins is wonderful). Whenever I start to despair and worry that there is not hope for humanity to accept science, I should go visit a natural history museum. They don’t hold back.
Now I just need to start planning my next trip back. Hopefully within the next few months! (and maybe I’ll schedule some time to be a tourist)
I have determined that a friend of mine, who works in another lab, has access to materials I could use for inflating caterpillars. I can’t wait until the collecting season starts and I can start on my own specimens.
While some inflated caterpillars are curated within the main collection, and some of them are grouped by family in the larval cabinets, there are many “miscellaneous” drawers with arrangements like this.
All sorts of caterpillars! The nice green color of the swallowtail caterpillars (bottom right-ish) was not preserved though. This seems to be one limitation of caterpillar inflation – patterns remain, but colors become lost or distorted. Most inflated caterpillars are some shade of tan/brown. This could be due to the heating process or simply by fading over time due to light exposure.
One thing I did not expect to see – everted osmeterium! Swallowtail caterpillars (Papilio) have an eversible gland called the osmeterium which is normally held inside the body. When threatened, the caterpillar sticks out the two forks and tries to touch the attacker – wiping them with smelly defensive chemicals. Just the smell could be enough to deter a would-be predator, but I’m sure the taste is pretty bad too.
Many of the geometrid caterpillars were preserved in their usual hunched position. I wonder if this was induced somehow during the heating process, or if they simply inflated into the most natural position?
I couldn’t help but include a photo of the megalopygids (fuzzy guys on the right). Preserving them must have been a delicate task, hopefully carried out with gloves – they can give quite a vicious sting! They look more like little mice than insects, and each hair can leave a welt on your skin. I was tempted to test whether old preserved specimens would still sting, but decided not to try.
Have any of you ever inflated a caterpillar specimen before? If yes, do you have any advice?