Cocooning

The weather here in northwestern Ohio has turned colder and wetter as we enter the depths of autumn. Humans turn to furnaces and fireplaces for comfort and survival, and insects have their various methods of doing the same.

This year I’ve been raising a polyphemus moth caterpillar (Antheraea polyphemus). I was given about a half dozen of the tiny early instar caterpillars back on August 23. They were feeding on maple leaves when I got them, but they can feed on a variety of tree species, so I was able to change them over to elm leaves. I have two maple trees but they’ve been trimmed so high that I can’t reach the leaves without a ladder. The elm tree has enough low-hanging branches that I could reach more fresh leaves each day.

I was excited to begin this adventure with a species I’d never raised before. Raising monarch butterfly caterpillars (cats) is a relatively quick and easy project, as they only feed for a couple weeks before going into their chrysalis form. I knew the polyphemus moth cats would take a bit longer, but I didn’t know much about what to expect along the way.

Polyphemus moth caterpillar eating elm leaf - Sept 10 2018 blog
The lone survivor eating an elm leaf – Sept 10

As it turned out, there were some surprises. The first was that I would only end up with one caterpillar. I’m not sure if the little guys somehow escaped the enclosure or if they ate each other, but after a couple weeks, there was only one left. You may remember that I wrote about my experience with milkweed tussock moth caterpillars back in August, in which I believe they cannibalized each other. You’d think that would have made me more cautious with this species, but I guess I assumed that the tussock moth cat behavior was some sort of anomaly. And besides that, these guys were so tiny and had enormous amounts of food available to them, I couldn’t imagine they would eat each other.  I don’t think they could have escaped from their enclosure either. But whatever happened, I ended up with just the single caterpillar after a couple weeks.

I fed him fresh elm leaves each day and waited  eagerly for signs of impending pupation. And waited. And waited.

Polyphemus caterpillar turning brownish - blog
Polyphemus moth caterpillar turning darker near the end of September

Near the end of September, he started to turn a darker olive green at the head end. I hoped that meant he was almost ready to make a cocoon, but it didn’t. I also wondered if he was sick or had been parasitized somehow. But after a couple weeks like that, he turned back to his bright green color and continued eating.

Before you go on, if you haven’t done it yet, I suggest clicking to enlarge one of these photos so you can fully appreciate the body structure of this fascinating insect. I just love the brown alien-looking face, and the colorful bumps that adorn much of the body. And the backside, which I’ve come to call the butt flap, where the relatively large pellets of waste are ejected. You can see one of the “pellets o’ poo” on a leaf in the background of this photo.

I took him out of his enclosure on Tuesday to take some more photos, and this turned out to be his very last photo shoot. Is he not amazing?! Look at those gripping feet!

Polyphemus caterpillar's last photoshoot Oct 30 2018 - blog

Take a look at the various dots of color along the abdomen in this photo. There are some with hairs (or setae) coming out of them, and then there’s a row of brownish spots without hairs; those are the spiracles. The caterpillar doesn’t have lungs like we do, but instead breathes through those spiracles. And by the way, if you’d like to read much more detail about the life cycle of this moth, check out this site from the University of Florida.

And it wasn’t until yesterday — finally — that he crawled into a dried elm leaf and began spinning silk to enclose himself. This photo was taken around 10:00 in the morning. Notice a few strands of silk on the left end of the leaf.

Polyphemus beginning cocoon 10-31-18 at 10 am - blog

And this one was taken when I got home around 6:00 pm.

Polyphemus beginning cocoon 10-31-18 at 6 pm - blog

And I took this final photo this morning.

Polyphemus cocoon finished on Nov 1 2018 - blog

He’s tucked in there nice and cozy now, and will spend the winter and early spring “napping.” And it’s weird, but I don’t quite know how to think about him in this phase. With monarch butterflies spending such a short time in their chrysalis form, it’s easy to imagine that they’re actively transforming into butterflies each day. But with these guys, I have no idea what happens in that cocoon for so many months. Does he stay in this caterpillar form, only transforming into a moth right before emerging in the spring? Or does he begin the transformation as soon as he’s wrapped up? I’d like to know the answer to that, but I also love wondering about it, letting my imagination run with the possibilities.

I’ve now put him in the garage for the winter, along with the four black swallowtail chrysalises that are wintering in there. Both of these species need to be exposed to the cold of winter so that their emergence in the spring will be at the same time as the rest of their species. That’s important so that they can find mates. The polyphemus moth doesn’t even have mouth parts to feed, so it will live as an adult moth for less than a week, just long enough to reproduce the next generation.

I’m anxious to see the moth and the butterflies eclose from their winter abodes next year. It’s going to be so hard to wait. I can imagine trudging into the garage all bundled up in February to get the snow shovel and seeing this cocoon tucked in the corner, with the caterpillar doing whatever it’s doing in there. I think that will bring a smile to my face no matter how much I hate shoveling snow.  #FindingTheJoy

A Speeding Green Bullet!

Autumn has long been my favorite season of the year — colorful tree foliage, cooler air for comfortable hikes, clear cerulean skies, cozy sweaters…I could go on. But this is also a season tinged with sadness for the end of summer.  Lately I’ve been feeling a bit gloomy about the impending end of dragonfly season. It’s frustrating to have such a short time each year to watch these fascinating insect predators.

I’ve written before about the Ohio Dragonfly Survey and how you can contribute to it. I’ve submitted many records of my observations to the survey in the past two years, and look forward to adding more in the third and final survey year next summer.  A few weeks ago I got a message from one of the survey coordinators pointing out that they would like a few 2018 reports from Fulton County, and asking if I would keep that in mind while I was out and about.

I live in Lucas County, which has a few very active odonata observers, including one of Ohio’s experts. So there’s not much chance of me finding something here that hasn’t already been documented. But Fulton County is a rural county just to the west of Lucas County, and it has far fewer people reporting odonata sightings. So that means I can more easily make a meaningful contribution to the database with my sightings there.

So the other day, after doing some online location scouting and armed with a list of three target species, I drove west through the corn fields.

The three target species were all damselflies: blue-fronted dancer, fragile forktail, and stream bluet. I knew one good pond location from earlier visits in that area, but I knew that spot wouldn’t be likely to have the dancer or the bluet, both of which are usually found near rivers or streams rather than the pond that I was headed to first.

I was pleasantly surprised when the first bug I saw was one of my targets, the fragile forktail. He’s easy to identify because of the green exclamation mark on his thorax.

Fragile forktail - blog
Fragile forktail (Ischnura posita)

I spent about 45 minutes more at this pond location, documenting some other species, before heading off in search of flowing water.

I went to a place called Tiffin River Wildlife Area. I was optimistic about this location until I got there and found that there was virtually no access to the water. I found one small gravel parking lot with barely enough room to turn the car around, but it was surrounded with head-high vegetation and no paths. Hmmm. This would require some ingenuity.  I drove around a bit and found a dirt driveway that dipped down toward the water, but it had a chain across it about 75 yards down and a sign that said “No Trespassing.”

Blue-fronted dancer - blog
Blue-fronted dancer (Argia apicalis)

I figured, okay, I can walk on this first section as long as I don’t go past the chain and the sign. I wasn’t going to do any harm, and it didn’t look like anyone had driven that driveway in a long time; it was full of deep ruts and bordered by tall weedy vegetation. And amazingly, I found my second target species on that driveway: blue-fronted dancer. I almost did a happy dance after I got my photograph for documentation.

I also got this pretty picture of a viceroy butterfly nectaring on loosestrife.

Viceroy butterfly w sig - blog

So, two down, one to go. The only other spot I could find with the potential for running water was Harrison Lake State Park. From the map view I’d noticed there was a dam at one end of the lake, with potential access to the stream below it. So off I went further west.

I’m sure it had a lot to do with the beautiful weather on this day, but this park impressed me immediately. I saw that their campground was full of people on this late summer Friday, but somehow it wasn’t noisy. It felt peaceful and relaxing. And even better, there was access to the stream below the dam, just as I’d hoped. And this is where something exciting happened.

I’d found a couple interesting species (orange bluet and dusky dancer), and was taking photos of them and just quietly observing the water. I was looking down at something on the ground, and as I lifted my head I saw an enormous pair of green eyes speeding directly toward me, only a dozen feet away. I barely had time to think “River cruiser!” when it whizzed past me like a green bullet and went high up into the trees behind me. I spent a half hour searching for it, desperate to document it for this location. I had a hunch it could be a species that hadn’t been recorded there before. But, alas, I didn’t find it again.

I eventually gave up and walked back up the hill to the top of the dam, and then slowly toward the parking lot.  I was enjoying the beautiful day, but couldn’t help feeling a bit dejected after the close encounter with the river cruiser and then losing it.

I was in the parking lot, about 100 yards from my car, when –BZZZZZT! — something big flew past my head and perched in a tree 30 feet above me. I knew what it was before I saw it: River cruiser!

Wabash River Cruiser - Fulton County Record (2)
Wabash river cruiser (Macromia wabashensis)

I started taking photos immediately, not knowing how long it would stay there. My first impression was that it was a Wabash river cruiser, a hard-to-photograph hybrid species. And indeed, that’s what it was! I couldn’t believe my luck, and took probably 70 photos of it, even though it barely moved. I always try to get multiple views of any dragonfly, because sometimes you need to see multiple field marks to confirm an identity. The diagnostic field mark on this species is the moth-shaped yellow mark near the end of the abdomen.

And not only did I get a killer view of this dragonfly, I photographed a really interesting behavior: the transfer of a sperm packet.

Wabash River Cruiser transferring sperm packet
Wabash river cruiser transferring sperm packet prior to mating

Prior to mating, the male has to transfer sperm from his primary sexual organ to his secondary genitalia, where the female will have access to it when they link their bodies in the mating process. This photo shows him doing exactly that.  And this made me believe that I’d seen two different individuals; the first one I saw below the dam might have been the female.

I felt great that I’d gathered some valuable data for the Ohio Dragonfly Survey (the Wabash river cruiser did turn out to be a new species for Fulton County), and I left that park with a smile a mile wide.

something-to-look-forward-to-594x800I’m so glad I take the time to write about these nature experiences; not just to share them with you, but for myself too. They’re fantastic memory joggers as I reminisce in the winter, sitting beside a crackling fire counting down the days until the first ode sighting next spring. I’m also planning to do some hard-core studying this winter, as I’ve been enlisted to lead the annual dragonfly field trip for Toledo Naturalists’ Association in June. I don’t need to be an expert by then, but I’d like to be as prepared as possible so everyone has fun and learns something on our outing.

A couple years ago I wrote about this little reminder I kept on my refrigerator, and it’s still working well for me. As long as I keep making plans for interesting things to do, life is good. 🙂