Nature and Gardening: Hey Neighbor, Can I Borrow a Cup of Milk . . . Weed?

This year I have a bumper crop of monarch caterpillars. Every milkweed plant is covered with them, and they are consuming all of my milkweed. There are few leaves left on any of the plants and some have been stripped of all leaves and flowers. The biggest caterpillars are eating the stems and even the seed pods, but the younger ones need leaves. Each time I find a chrysalis, I think, “good, one less mouth to feed!” Finally, I began calling neighbors asking if I could romp through their fields in search of milkweed. I found a small patch in one neighbor’s field that hadn’t been mowed. I cut one large stalk of the common milkweed, put it in water, and transferred a few caterpillars onto it. Tomorrow I will cut another stem.

I thought I planted plenty but now I feel like a poor mother with too many mouths to feed and not enough food to go around. Adult butterflies only drink nectar from flowers, but caterpillars are eating machines. As they eat and grow, they shed their skin about five times during the larval stage. The time in between shedding is called an instar.

Actually, seeing lots of monarch caterpillars is good news because in the past 20 years the monarch population has decreased an estimated 90 percent. There are many reasons, including deforestation where they winter in Mexico, and loss of habitat, especially in the midwestern corn belt and wheat belt.

Survival is difficult but I am hopeful that some of my caterpillars will become the adult butterflies that will make it all the way to Mexico.

Monarch Life Cycle

Egg – 3 or 4 days. Monarch butterflies are host specific, laying their eggs only on milkweed plants. A female can lay several hundred eggs in her short lifetime.

Larva/Caterpillar – 10 to 14 days.

Pupa/Chrysalis – 10 to 14 days.

Adult/Butterfly – 2 to 5 weeks. The last generation that emerges at the end of summer will live 8 to 9 months and migrate to Mexico.