It is early autumn, and the super generation of monarch butterflies – those destined to live long enough to fly to Mexico — is hatching as caterpillars from barrel-shaped eggs laid meticulously on the underside of milkweed leaves. While the butterflies that laid the eggs will never make the epic journey south, this generation will.  

The tiny, striped caterpillars eat their way out of the egg and feed on milkweed leaves. As they grow, they shed their skins several times, then hang upside down, forming the shape of the letter “J”. With their final molt, they begin the miraculous transformation into an adult butterfly.

Unfortunately, not every caterpillar will survive. Hungry wasps are hunting them down. In my daughter’s Maryland backyard, my wife found a paralyzed caterpillar about to be eaten by a yellow jacket. The yellow jackets sting the caterpillars, carrying them back to the colony to feed the queen and worker wasps.

Fortunately, during her lifetime, the female butterfly laid hundreds of eggs—one here, one there — on milkweeds along roadsides, in meadows and backyard gardens. If even just a few caterpillars survive, it will help maintain a healthy population for the species. Those that survive will ride on warm air currents south, guided by the sun and their magnetic compasses, flying up to a hundred miles a day, until they reach the central Mexico forests where they overwinter.

Yet, monarch populations continue to decline due to human activities. When milkweed patches are cleared or ploughed and insecticides are used to control pests, monarchs are left struggling to survive.