Luis:

I’ve always been interested in biology, so I take organisms in often. One day I brought in a caterpillar, it pupated, and on a dark summer night, I noticed that it was eclosing! I hurried to get my camera, I positioned it, and started taking pictures. Suddenly, without any warning, it’s little shriveled wings started to expand at an AMAZING rate. It was done “inflating” it’s wings in about 3 seconds, and was pretty much able to fly just as fast. Admittedly it was a small moth, with a wingspan of about two inches, but I was still amazed. (I tried to video tape it, but by the time I had switched to the “video” mode, it was done). [Note: See pictures above taken by Luis]

Here’s my question: I rarely get to see my lepidoptera eclose, so what would you say is the average span of time in which lepidoptera (or other insects) “inflate” their wings? Thanks!

Many people may be unaware that this behavior (wing pumping) takes place. So what happens is, as the butterfly or moth emerges/ecloses from their chrysalis, it must enlarge its new cuticle and expand its wings before the epicuticle hardens. See, when they emerge their cuticle (insect ’skin’) is very soft and the insect is very vulnerable, which probably explains why most people do not see this behavior take place because the bugs tend to hide. The insect pumps up its wings by swallowing in air and forcing hemolymph (insect blood) into the wings. Supposedly, if you cut the tips of the wings off of a dragonfly once it has emerged, hemolymph will drip from the tips as it pumps its wings, and as a result the wings will never expand completely.

What is the average span of time in which leps “inflate” their wings? Honestly, I don’t know of a very academic answer to provide because I think it is highly variable, depending on the environmental conditions, pre-programmed motor output, hormones (i.e., busicon, a cuticle-hardening hormone) among other things. For example, you noted that it only took about 3 seconds, but in the tobacco hornworm I think they have documented that it takes about 30-75min for wing expansion. Experiments performed by Truman and Endo (1974) showed that if you decapitated a tobacco hornworm as soon as it eclosed there was no wing pumping. But if you decapitated the moth 5 seconds after emergence the moth continued wing pumping. Similarly, if you cut off the abdomen the moth still continued to pump its wings. Injections of bursicon into moths who had their abdomens cut off showed a reduced amount of time in wing expansion. So the authors determined that bursicon had some role in the termination of wing pumping.

Image courtesy of eNature.com (John Coffman)

I’m sorry I can’t give a better, more conclusive answer. Perhaps another reader will have more insight into this and will comment.

Well, not quite. But he did fancy the box that a church for a Christmas village came in.

Neshan:

Can June bugs see? Why do they crash into things, etc? My friends and I cannot figure it out or find it on the internet.

Image courtesy of bugguide.net

“June bug” is a common name given to the beetles (mostly of the genus Phyllophaga and Polyphylla) in the Scarabidae family. They are a well known insect and can be seen bouncing off screens and porch lights in early summer.

They can indeed see (note the compound eyes in the picture above). In fact, that is why most people see them at night around their porch lights…because they are attracted to light. It is probably fair enough to say that their sense of smell is better than vision. Their antennae are quite distinctive, they are club-shaped and made up of plates (lamellae). The antennae can be folded in together (as in the picture above) or fanned out. (Note: In the picture above, the antennae are the big, orange-ish structures that might be mistaken at first glance as the first pair of legs.)

So, why do you always see them bumping into things? Well, as a general observation, beetles are fairly clumsy fliers. In that respect, june bugs kind of remind me of myself on rollerblades…once I get going, I pretty much need to just roll smack-dab into something in order to stop or slow down

Poor Gunther hasn’t had a post in a couple of weeks. Poor, poor kitty.

Anyway, to make up for it, today’s post will include a picure story of sorts. The title, “Cat Meets Darkling Beetle. Cat Loses.”

First Encounter

If that isn’t an evil eye, I don’t know what is.

Nothing Wrong With A Little Caution

Does It Smell?

I can answer that for the cat…yes. This tenebrionidae beetle, when threatened, takes a defensive stance that kind of looks like a hand stand. Then, the beetle emits a noxious odor from the tip of the abdomen.

Beetle On The Defense, What Does Gunther Think About That?

Beetle Takes All, Cat = Sore Loser

Gunther took about 10 steps back. Apparently he didn’t want to play anymore after their brief exchange.