See sphinx caterpillars up close and personal.
By Kris Wetherbee, Oakland, Oregon
If you want to see the metamorphosis of the sphinx moth in action, find a caterpillar before it pupates and watch the magic unfold inside a glass jar. Sphinx moths typically pupate in loose soil (smaller species on the surface in leaf litter), so it's best to provide about 3 inches of soil and dry leaves in the jar.
Include twigs and freshly cut leaves from its host plant, and continue to offer fresh leaves until the caterpillar pupates. (Don't forget to add holes in the jar lid so the caterpillar can breathe.)
Late generation caterpillars that overwinter in the pupal stage will need a cold period, which can be provided by placing the jar in an unheated garage or a protected area on the north side of a building.
After most of the trees start to leaf out in early spring, bring the jar inside to watch the winged adult emerge. Be sure to set the sphinx moth free within a day of emerging.