Many, many thanks to Maggie McCartney and Thomas Waser in our Herpetology Department for spotting this incredible caterpillar on our Museum grounds! It's a polyphemus caterpillar--my index finger is shown for scale. And, yes, the caterpillar really is almost a neon green color. I took these photos on September 15, 2012.
And, it seems my cocoon wasn't the only one found on the Museum grounds! Horticulture staff member Darl Fletcher and educator Judy Molnar pointed out yet another polyphemus caterpillar making a cocoon--this one in the leaves of a tropical milkweed plant located in our horticulture support area. I was able to get a shot of the face, with the bright yellow line on the first thoracic segment, and also a detail of those lovely silvery "warts" and finally a look at the caterpillar as it began to draw leaves around itself to make the cocoon--do you see the fine silk strands?: