The Little Green Eggs (conclusion)
(click on a photo to enlarge)
It took 40 days for the Hubbard’s Small Silkmoth (Sphingicampa hubbardi) caterpillars to complete this stage of their life-cycle. Two days after hatching and feeding on mesquite leaves the caterpillars, originally just a few millimeters in length, began to green up and grow.
Notice the subtle changes that took place over the next few weeks. Mostly they just got longer and larger.
After a week, some changes are noticeable along the back. The small, hair-like spines (scoli) are now larger and more colorful and the horn at the tail end is more prominent. White and yellow colors are more noticeable too.
Not much change between 7 and 11 days except for some subtle red hues in the enlarging scoli.
At 19 days, the caterpillars are about an inch in length, deeper blue-green and the scoli are becoming more tinged with reds and blues.
By day 25 the last instar stage has been reached. The caterpillars are about 1.5″ in length. They are handsome or grotesque depending on your viewpoint but no one can deny that their coloration and overall appearance is outstanding.

Psychedelic Colors (9/15, 26 days)
After reaching their final growth stage, which lasts about a week, the caterpillars stop eating and begin wandering in search of a place to pupate. They often attain a deep rosy coloration at that point.

Wandering Adult Ready to Pupate
Normally they would burrow into the soil and then shed their skin. However, shedding on the floor of the terrarium seemed to be okay with them too. The pupa forms under the skin which then wiggles its way out.
The pupa will overwinter and hopefully emerge next spring. The plain coloration of Hubbard’s Small Silkmoth adults gives no indication of their colorful caterpillar history except for the rosy underwings that are useful to flash should a predator consider them for a meal.
Published by Arlene Ripley on December 7th, 2009 Tagged Arizona, Cochise County, Insects, Moths, Nature












December 11th, 2009 at 6:40 pm
One thing I’ve always been intrigued by is the order of nature, and how delicately it’s all balanced. One thing can cause a domino effect on so many others. Great posts here!
December 13th, 2009 at 1:38 am
Amazing series of images – great post that beautifully illustrates the life cycle of this moth. Very cool!