The Luna Moth: A Photo Essay

One of my goals for this past summer was to find as many moths in the family Saturniidae as I could. The saturniids are the moths that give moths great publicity: they're huge, they're colorful, and they make their presence known. In fact, this family includes North America's largest native moth: the Cecropia moth.

The Cecropia moth: Hyalophora cecropia. With a wingspan of up to 6 inches, it is a HUGE moth.

I was out at the Barbara A. Beiser Field Station often during the summer, and on my first day there, in late May, I struck gold. As I knelt down to examine a Clubtail dragonfly (Gomphus sp.), I heard a strange rustling in the grass nearby. I took a few quick snapshots of the dragonfly and turned around to see what was causing the ruckus. I could hear it, but due to the dense, wet, matted grass, I couldn't quite find it. 

And then I saw it.

But...what was it, exactly? My eyes darted around, surveying the yellow, white, and maroon mass crawling towards me. At first, it looked like two beetles wrestling and falling through the undergrowth. Confused, I took a closer look and realized what was actually coming at me.

Trust me, that totally looked like two beetles when I first saw it.

Full of glee, I realized that I was looking at a Luna Moth (Actias luna), one of the saturniids I was searching for! However, it did not look like what the Lunesta commercials had led me to believe what a Luna moth looks like. First of all, it did not glow. Secondly, its wings were shrunken, and the abdomen looked distended.

Not yet ready for flight.

There could be only one explanation: this individual had just emerged from its pupa! That's even more exciting than finding an adult flying around! I knew then what I had to do.

 Need a hand?

To avoid accidentally stepping on it, I picked it up and placed it on a nearby maple tree.

 

That's not quite what you're used to seeing from a moth, huh? The abdomen was bulging with that green stuff, which I assume is hemolymph that it was planning to use to pump up its wings.

Notice the antennae and how plumose they are: that indicates a male. The males need huge antennae to pick up the pheromones of the females, a surefire way to find a mate!

After placing it safely upon the tree, I waited. Not wanting to waste all day watching a Luna Moth pump up its wings (it's like watching paint dry, but more beautiful), I went along to find assassin bugs and other marvelous insects, returning at times to check up on my Luna Moth.

After three minutes of being on the tree, the Luna Moth has already set to work! You can see the wings are starting to flare out and enlarge, while the abdomen has contracted a great deal. It's becoming much more plump and much less thin. 

Just nine minutes later and the wings are hanging like trendy curtains. The eye spots on the forewings give it a look akin to the face of a wrinkly old man.

15 minutes later and you can definitely see the face of an old man. The eye spots have really come out now. Speaking of which, have you ever wondered what those eye spots look like under a microscope? Or, where the term "Lepidoptera" (the name of the order that includes the moths and butterflies) is derived from? Well, thanks to Wikipedia, your questions can now be answered!

Source

This picture by Peter Znamenskiy shows what those eye spots really look like. You see, "Lepidoptera" is derived from the Ancient Greek words lepís and pterón, the words for scale and wing. Put those words together, and you get an order of insects that have scales on their wings. Those colorful structures that look like paintbrushes are the scales, and they give this moth its awe-inspiring colors.

20 minutes later, and we return to the Luna moth. The abdomen is now obscured by the wings, so we go in for a side view. Yep, that is one plump abdomen. But what's this? The hind wings look a bit wonky. You didn't forget that moths have two pairs of wings, right?

30 minutes in, and the moth seems to be imitating a butterfly: its wings are held above the body vertically, rather than horizontally. What gives? Well, he still has a second pair of wings to pump up, wouldn't it be easier to do that without the first pair holding them down?

After 35 minutes, it looks like the second pair of wings have a comma at the end. They probably need to pause before they finish their sentence.

Well how about that? At 55 minutes, the hind wings bring with them some nice streamers. The Luna moth is ending its sentence with an exclamation point, for sure!

He's still working hard at 1 hour and 15 minutes. Art takes time, after all.

After 1 hour and 40 minutes, you might be asking yourself: "What's with the streamers? Is the moth going to throw a fancy party?" The answer to that question is yes and no. Here's the reason for answering no: The hind wings also have eye spots, and combining the eye spots and the tapering ends of the wings might be just enough to confuse a predator (such as a bird) into aiming for the rear quarters of the moth, rather than its head. If the bird grabs the streamers, the moth still has a chance to get away. Now, why is the answer also yes? Well, the adult Luna moth does not eat. Therefore, it only has a lifespan of about one week. Due to this, the adult Luna moth lives its adult life like it's one big party. Its sole raison d'être is mating, and it devotes itself to this debauchery at full throttle. If it doesn't pass on its genes, it has literally failed at life, hence why the males have such big and sensitive antennae. If you pick up the female's pheromones, you win the game of life.

2 hours and 10 minutes later, the moth is still preparing for his fancy party: putting up streamers, acting chill, and making sure he looks good for the ladies.

Finally, after 3 hours, he's......still not ready for that fancy party. I, however, am famished. After about 7 hours at the field station, I must head out, eat, and rest. 

I loitered around for as long as I could, but I could not stay and watch the Luna moth finish up. It was fascinating to watch it progress from stumpy little cushions to bona fide tapering wings, and I found a new appreciation for these Moon moths. This was definitely a check on my list of saturniid moths I needed to see. 

So, as I often say, if you think Ohio's diversity of insects is nothing to praise, think again!

Summer Research 2011 - A Biological Survey of the Assassin Bugs (Hemiptera: Reduviidae) at the Barbara A. Beiser Field Station - Other Insects

This past summer, as I mentioned a few times before on this blog, I had the opportunity to carry out a field survey for assassin bugs at the Barbara A. Beiser Field Station. This field station is used by the biology classes at Marietta College for lab sections, such as Zoology and Aquatic Biology.

I knew that I would have a good portion of free time during the summer, and I wanted to get a head start on my capstone project, and do some more research with insects. Out of that grew a project during which I would research the abundance, diversity, and ecology of assassin bugs (insects in the family Reduviidae). I wrote up an application for an Investigate Studies Grant for these types of student-led projects from the college, and I received one to carry it out.

It took place during six weeks in May and June, and I found a lot of different species--both assassin bugs and other insects. I focused on the assassin bugs most of the time, and presented on my findings (I'll elaborate on that in another blog post, but I found 7 different species of assassin bugs) in October. Since then, I've been focusing on all the other insects I found during the project. In order to save time and keep focused, I didn't collect every insect I found, but I did try to snap some pictures whenever I found something I hadn't seen before.

Like this, for example. A scarab beetle, the Emerald Euphoria - Euphoria fulgida.

Fast forward to this past week, and I've been focusing on identifying all the insects and other arthropods I saw. Assisting me with that has been Project Noah, an amazing website that anyone can submit their pictures of wildlife to, upload them to a map, and essentially crowdsource nature with others. (It will receive its own blog post in the future.) I just finished uploading all my pictures from my Investigative Studies Grant project, which gave me a lot of time to reflect on everything I encountered. 

It also gave me a number: 137 separate species of insects, plants, spiders, fungi, slime molds, and miscellaneous other groups of life just from those 6 weeks. 

That's not too shabby, if I do say so myself. Since it's the time of year to write reflections, I figured that now is as good a time as any to briefly highlight some of my favorite photographs and organisms I encountered. I'll limit myself to five to keep the length of this post reasonable.

This was the first insect I encountered--right on the gate leading to the field station. Unbeknownst to me at the time, I would be seeing A LOT of soldier beetles (family Cantharidae). This particular one is Podabrus tomentosus, which I didn't see many of in the interior of the forest. You know what I did see a lot of? Firefly mimics. Firefly mimics EVERYWHERE. It wasn't even until I was reviewing my photos that I even figured out that most of what I thought were fireflies were actually soldier beetles in disguise. That being said, that is some amazing mimicry. (Consider that paragraph a cliff hanger, I'll cover these mimics in another post.)

Serendipity is better than skill! I got lucky on my first day at the field station and stumbled upon (literally, I almost stepped on it!) a luna moth (Actias luna) that had just emerged from its pupal stage and was crawling along in the grass. Adult luna moths only live for a week and do not only: they only live to reproduce. I had never encountered a luna moth before, so I was excited out of my mind when I found this male (notice how large the antennae are, that's how you can tell the difference between males and females). Not wanting to step on him, I picked him up and placed him on a tree so that he could pump up his wings in peace. I returned every so often over the course of three hours to watch and it was just a beautiful sight. It's a real privilege that we have such a majestic moth in Ohio.

This is the Orange-patched Smoky Moth (Pyromorpha dimidiata), a rare case in which the common name describes the organism extremely well. At first glance you might be reminded of a net-winged beetle in the family Lycidae. It's suspected that this moth is a mimic of those beetles (check out the genus Calopteron for comparison), but may also have its own chemical defenses. Due to this, the mimicry exhibited by this moth and the net-winged beetle is characterized as Müllerian mimicry. 

Since both species are toxic and have similar aposematic (fancy word for bright warning color) patterns, the mimicry works to the advantage of both organisms: predators leave them alone since they're distasteful. This is opposed to Batesian mimicry, in which a model toxic species is imitated by other non-toxic species, which obtain the same benefits without needing to be toxic themselves. It's the insect equivalent of putting your purchase on someone else's tab. For more information about this species, you can check out Ted Macrae's entry at Beetles in the Bush.

Next up is a beautiful firefly I found crawling on a decaying log.

Or is it?

Fireflies must be awesome beetles to mimic: even the click beetles (family Elateridae) are getting in on the action! Here we have Denticollis denticornis. Sorry, no common name here, but for simplicity we can refer to it as the firefly mimic click beetle. I mistook it for a firefly when I first saw it, but upon closer inspection, the flared pronotum that fails to cover the head gives it away as a click beetle. Simply a beautiful specimen, I wish I had taken the time to get some more pictures and see where it was going. Now, which mimicry would this click beetle be exhibiting: Müllerian or Batesian? For a nice discussion about mimicry's benefit to this species, check out this link to BugGuide.

Finally, we come to one of my favorite beetles: the pleasing fungus beetle Megalodacne heros. It's in the family Erotylidae and looks as if it should be coming out around Halloween. Unfortunately, this beetle is on the wrong calendar and is restricted to the summer months.

As you can guess from the common name, the beetle feeds on fungus. In this case, I found it chewing on some bracket fungus as night was falling. It's a large beetle (two centimeters long) and its elytra are quite smooth. After I captured it and took it back to the lab, I was watching it move around under the microscope. As I watched it move its leg (it had flipped itself on its back), I was awed by how smooth its movements were.

Truthfully, this beetle showed me how beautiful insects could be, just by something as simple as their movement. It was a "Eureka!" moment for me, and has ensured that this beetle will stay at the top of my list of favorite insects. 

Too often we recoil at insects and other small arthropods because they look ugly or creep us out. Casting them down in judgement is ignorant and quite offensive to how elegantly they go about their lives, however. Not until you take the time to immerse yourself in their world (that is, what life is like for organisms that are measured in inches at most) can you truly appreciate the beauty and real magic that nature exhibits.

If you're interested in seeing more of my photographs from the Beiser Field Station, you can find my collection on my userpage at Project Noah.