Upon closer inspection, and to our delight, we discovered the hungry leaf eaters were Monarch Caterpillars!Female monarch butterflies lay their eggs on milkweed, which
is the only plant monarch caterpillars can eat. They lay one egg to the underside of a milkweed leaf. The eggs are very small and are whitish in color. Three to six days after the eggs are deposited, they will hatch. We think our tiny little caterpillars hatched over the weekend.
Immediately after hatching, the caterpillar is so small it can barely be seen. It grows very fast though, feeding on nothing but milkweed leaves. In just 9 to 14 days it is about 2" long and fully grown.
When the caterpillar is full grown it usually leaves the milkweed plant. It travels until it finds a safe place to pupate.
The caterpillar then passes from the larval (caterpillar) stage to the pupa (chrysalis) stage of metamorphosis. In this pupa stage the caterpillar is inside a jade green casing which is called a chrysalis. Inside the chrysalis, which is only about an inch long, the caterpillar will amazingly transform into a beautiful butterfly. In just 9 to 14 days the transformation from caterpillar to butterfly is complete.
About one hour after emerging from its chrysalis, the monarch's wings are full-sized, dry, and ready for flying. Four to six days after emerging from its chrysalis, a monarch butterfly is old enough to mate and thus begins the life cycle of the next generation.
But right now our milkweed plant is being devoured by these hungry little caterpillars, which will soon reduce the milkweed plant to bare stems. But no worries, the foliage will grow back in a few weeks, just in time for the next generation of monarch caterpillars!
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