Here are some more inflated caterpillars from the Smithsonian NMNH (click here to see some from Cornell’s CUIC).

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.

It appears that size is not much of a factor – I saw inflated caterpillars of all sizes (the smallest was about 1cm long).

A picture with my hand hovering just above the glass, to give a sense of scale. I wonder what the guts of those caterpillars looked like when they were squished out?

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.

I love how the spines and body shapes are preserved in this one!

Many trays and drawers feature small drawings and paintings – sometimes in place of a specimen, sometimes as a helpful reference.

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?

Even the spiny limacodids were preserved this way. I was surprised to see one bright green specimen! Perhaps there is hope to preserve coloration after all.

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?