White Underwing Moth
Back around the end of September 2011, while I was at work, this moth flew into my office and died[1]. It was pretty large and striking, and I saw it come in. But, when I tried to catch it, it flew behind some bookshelves and I lost it. It wasn’t until some weeks later that I moved a stack of books, and found its dried-out corpse lying there by pure luck. So I brought it home to photograph.
This was another underwing moth, genus Catocala. We can see some of the underwing in the next picture, showing that the hindwings are black with white stripes, and the topside of the abdomen is black:
And luckily, it turns out that there is only one local underwing moth with that coloration, so I am pretty confident in declaring this to be the White Underwing, Catocala relicta.
A lot of large moths don’t have noticeable mouthparts because they don’t feed as adults, but not this one. You can see its coiled-up “tongue”, or proboscis, there on the underside of its head, it looks like it would uncoil to be quite long. The proboscis is essentially a straw, allowing the moth to suck nectar out of the bottoms of even quite elongated flowers[2].
The antennae were long and threadlike (you can barely see one of them trailing up over the moth’s shoulder), which makes me think that this was most likely a female.
Initially, I was cautious about trying to manipulate it to see the hindwings better, because it had dried out and was very brittle. But then, after getting the pictures above, I figured it was worth a shot to try “relaxing” her so the wings could be spread. So first, I took a piece of paper towel, soaked it with hot water, and put it in the bottom of a small jar. Then I put the moth into the jar, closed the lid, and left her for several days. This let the body soak up moisture from the air, and re-soften enough that the wings could be moved without snapping them off.
Then I put her on a spreader board that I whipped up from a piece of plastic foam insulating sheet, and carefully spread out the wings as far as I dared. Then the wings were strapped down with strips of paper and pins to hold them in place, and I let her dry out again.
And here she is, with the wings spread out and underwings almost completely exposed. Not the most beautiful job on my part, but at least we can see her rather striking underwings better now.
The caterpillars feed on aspen, poplar, and willow, and are quite hard to find because they tend to stretch out along branches and lay flat, blending in with the aid of the little fringe of protuberances that run along their undersides.
———
[1] Somehow, that reminds me of the song“Please don’t bury me down in that cold, cold ground”, which starts
“Woke up this morning,
Put on my slippers,
Walked in the kitchen, and died!”
[2] The relationship between flowers and the insects that feed on/pollinate them, is kind of intricate. What the flower needs is a faithful insect that prefers to feed on it and its close relatives, forsaking all others. That way, the pollen that the insect picks up from one flower will get transferred to another flower of the same species, where it can actually do some good. Meanwhile, what the pollinator wants is a fast meal that doesn’t take too much energy to get, that it doesn’t have to share with other insects, and that also will be available whenever the pollinator is active. So flowers and pollinators co-evolve to suit each other. One of the things that they will do is flowers will evolve progressively deeper nectaries, so that a pollinator needs a longer and longer tongue to reach it. That way, only the long-tongued pollinators (like moths) will even be interested in the flower. And, of course, once they can reach the deep nectaries, the moths specialize in those flowers, because they are less likely to have been sucked dry by, say, honeybees [3]
Sometimes they will get into kind of a runaway situation. If the moth’s tongue is longer than the nectary, then it doesn’t get its face right down into the blossom and so doesn’t transfer pollen well, so the longer flowers end up getting pollinated better than the shorter ones. Then the longer-tongued moths can feed better than the shorter-tongued ones, so you end up selecting for long tongues. Whipsaw back and forth a few times, and you can get into a situation like a particular orchid/moth pair in Madagascar. It seems that Charles Darwin was once sent some specimens of the orchid Angraecum sesquipedale, which is notable for its very long blossoms with extremely deep nectaries, about 18 inches long (“sesquipedale” means “foot-and-a-half long”). Darwin noted that such a deep nectary only makes evolutionary sense if there is a pollinator that can reach it, but at the time no such pollinator had been discovered. So he predicted that there must be an undiscovered pollinator, that would be active during the period when the flower bloomed, and that would have a proboscis at least as long as the depth of that nectary. He thought it would probably be a “hawk moth”, which are known for their long tongues. It took until 21 years after he died, but eventually that very moth was discovered: Darwin’s Hawk Moth, with a tongue many times longer than its actual body.
[3] Sometimes the “long blossom” strategy backfires if there are pollinators that can take a short-cut around the blossom. For example, blueberry blossoms are shaped to force bees that are after the nectar to crawl in, past the pollen-bearing anthers. But carpenter bees are too big to fit, so they just chew a hole in the side of the blossom so they can get to the nectar. And, when they do this, they and all other pollinators drink all the nectar without ever going past the anthers, and the flower doesn’t get pollinated at all!
Comments are closed.
Fascinating footnotes.
For some strange reason (probably because I am depressed over the lengths to which politicians in Alberta are going to suck up nectar from citizen repositories (the public purse) as evidenced by the recent case of the MLA hawk—Mr. Berger who flapped his wings from a safe perch as a Tory MLA (i.e. got fired by voters) to go to the gauntleted hand of the same department (patronage job) to feast yet again on citizen mouse—(he got paid when he was fired by citizens in the spring election the tidy amount of $150,000 for the transition time of a couple of days before he got a job with the same government for a similar sum of money) and so this long proboscis business just reminded me of this fiasco. In Alberta even when you fire your politicians you still have them with their long proboscises deep in the nectar zone.
I don’t mean to taint your beautiful moth or your post with the grubby acts of the Progressive Conservative party of Alberta for your moth is at least providing valuable pollination services to a flower she is faithful to unlike the Tory party in Alberta that has merely been a sort of rat like infestation of our province that we haven’t yet managed to eradicate but hopefully will in four years time unless the citizenry is entirely dim witted as I have been in the spring election in believing their fluff and blathering. Your post is commendable for the lengths you have gone to provide the readers with meaty and unusual aspects of an insect we would be most prone to swat and remove from our vicinity than attempt to do science on (well this would be the case at our house where both younger boy and I would be hiding out somewhere while my husband and older boy did the work of capture/murder/dumping of the insect).
The carpenter bees that also you mention in the post, unlike the moth— seem to be a better fit for comparison with the politicians I am depressed about —–in their propensity to chew holes in the fabric of a flower as do these unscrupulous folks we have hired to chew holes in the public purse so that they have all the nectar they could hope for. Meanwhile we have folks living on the streets in downtown Edmonton.
But again I must do some chatter about your moth and ignore the unkind thoughts in my head about Progressive Conservative politicians in Alberta. So let me focus.
She is a very pretty moth. Yes, I will now leave politicians alone and comment on your extreme efforts to make her less of a desiccated corpse and more of a life like organism. I am going to spend the rest of this yapping time admiring your work.
1) first I like that you did not kill her but waited for her to naturally expire.
2) I mean I know you tried to kill her –I mean –catch her for the purposes of scientific investigation but she evaded you.
3) I like that you move stacks of books as well and find dead insects as I often do. But unlike you I don’t touch the bugs I find but shriek and run off.
4) I like the first picture where she is a very prayer-like position as if to say –“Oh just get it over with won’t you?” She makes me feel I could reach this state of fatal acceptance one day.
5) She also looks so plush I might even have touched her. The second picture makes her look just like the dumb Snowshoe hares in my community who sit and look like this –but in the middle of the street as you drive your car right at them and wait for death. The bunnies are not very bright but at least they are as plush as this bug.
6) Picture # 3 of the mouth parts was frightening. I took younger boy to see Dr. Kurji (his sweetie of a dentist) today and the insides of his mouth where he had failed to reach in his brushing and flossing looked remarkably like this except for the extensive mouthpiece.
7) Surely it must be difficult to fly around with that size of a nasogatric tube stuck in your innards?
8) And what is that large round eye like thing above the proboscis? Is it an eye?
9) I suppose it is an eye. Your antennae picture makes a case for it being an eye. I suppose I could just go to Wiki but I don’t. The antenna looks like a thin thread for a kite.
10) I like your bravery in tackling resuscitation of the creature. Well I mean reviving the creature in terms of its appearance. It isn’t quite taxidermy but it does do the job in making her very vivid to us.
Although your description here sounds more like a torture session:
So first, I took a piece of paper towel, soaked it with hot water, and put it in the bottom of a small jar. Then I put the moth into the jar, closed the lid, and left her for several days. This let the body soak up moisture from the air, and re-soften enough that the wings could be moved without snapping them off.
Then I put her on a spreader board that I whipped up from a piece of plastic foam insulating sheet, and carefully spread out the wings as far as I dared. Then the wings were strapped down with strips of paper and pins to hold them in place, and I let her dry out again.
11) The notes after the post were useful. I never knew that moths were specialized in this way. The bit about the “runaway situation” rings true. As it is for moths so it is for the politicians in Alberta. But i wasn’t going to talk about pigs at the trough or dogs at the rabbit or mice at the cheese, I was going to focus on the moth. Right.
12) This is a long post isn’t it? But I will stop now. It is always fun to come to your blog and as I am not writing right now on my blog (I am trying to revive my parents who are as ancient as your moth but not quite in this state yet) I am going to write in other folks’ blogs for no good reason than because I want to.
I borrowed one of the images and used it in a post scheduled for later today, linking back here. Hope you don’t mind!
KT: Nope, I don’t mind at all. Thanks!
Julie: You wrote,
“I am going to write in other folks’ blogs for no good reason than because I want to.”
That sounds like the best reason I’ve ever heard for leaving comments on blogs!
Thanks, amigo!