Tuesday, May 30, 2017

Regal Moth and the Devil

The pictures above were sent to me by a dear friend who shall remain anonymous except to say that she is a real Trouper.  In case you missed school on the day there was sex education, this was X-rated in my day but is now probably only PG-13.  

The stars of the show are Regal Moths, aka. Royal Walnut Moths, Citheronia regalis, the largest moth by mass in North America.  Like other saturniids such as the Luna and Cecropia Moths it lacks a digestive system.  They fly for up to a week, males searching for the fairer sex with their feathery antennae.  After mating and laying eggs they pass on to the great walnut tree in the sky.

Hickory Horned Devil - Click to enlarge

I was excited (not that way) to see these pictures as this is a Most Wanted species for the Butterfly Festival.  The photographer was able to find them hours later and put them in a large paper bag.  The female will lay her eggs on the walls of the bag and the caterpillars will be raised safe from predators and parasites. The final instar is the Hickory Horned Devil which we hope will come of age in time for the Caterpillar Petting Zoo.

This is the largest caterpillar in the US, measuring up to 6 inches long, and also one of the coolest.  The prominent horns on its head rounds out its fearsome appearance but it is really harmless unless you happen to be a tree.*  Pity the poor sweetgum in this time-lapse video.  Although their horns are not sharp, they can defend themselves with some devilish dance moves as seen in this  Youtube video.
First instar with egg **
Third instar - Delaware Nature Society
Late instar - Jon Rapp
Like many other Lepidoptera, there is a considerable difference in color and appearance between the first caterpillar instar out of the egg and the subsequent four instars.  The final instar turns from a bright green to turquoise over a day.  It finally crawls down to the ground and burrows a chamber five to six inches deep.  There it forms a pupa without spinning a cocoon.

 Be sure to save the date of June 24th to see the devil up close at the Butterfly Festival at the Springfield Botanical Gardens.

Video by Dr. Chris Barnhart
* These caterpillars feed on several trees and shrubs including walnuts, hickories, buttonbush, persimmon, sumac, and sweet gum as well as (good news!) invasive bush honeysuckle.
** Imageshack.us/photo