We’re now at a critical time for our Monarch Butterflies: The “miracle generation” of the species is being born. This fourth summer generation here will not only be the only one to live beyond a few weeks, it will migrate south to southern California or Mexico.
Meanwhile, members of the previous Monarch generation are now taking their last sips of nectar, as this one was doing earlier in the week:
The life cycle of of each generation of Monarch Butterflies consists of four phases. The first is an egg, about the size of a pinhead, that is deposited on the underside of a milkweed leaf by a pregnant female Monarch Butterfly. She lays hundreds of eggs one at a time on this plant, which is poisonous to many predators.
The eggs quickly develop into the second phase, Monarch caterpillars (larvae). These are brightly colored to warn predators that they are poisonous from eating milkweed, the only food that they eat. The availability of this restricted diet has been a cause of concern over the years.
After about two weeks of gorging themselves, the caterpillars climb to a nearby high point — which often isn’t a plant — and spin themselves into chrysalises, the third (pupa) phase of the Monarch. In those chrysalises, a caterpillar will metamorphose into a primordial goo that incredibly solidifies into a tightly folded insect.
Usually, within two weeks from the time that the chrysalises were formed, the insects emerge as Monarch Butterflies, the final phase of their lives. Birth from that chrysalis can be a brutal struggle that lasts days, as it did for the female Monarch making her September 14 full emergence shown below. Once out of the chrysalis, this exhausted butterfly fluttered awkwardly to the ground, where she stretched and slowly moved her pristine wings for about 15 minutes.
Then, she flew erratic short and low trips for about 30 minutes, before soaring away on a breeze.
As mentioned, most Monarch Butterflies die within six weeks of their emergence during the summer. But not this female and other Monarchs born here as the days get colder in September and perhaps early October. They’re different in some unknown way. The future of their species here is their responsibility. Soon, they’ll somehow feel a duty to fly to southern California or Mexico, where they’ll rest in semi-hibernation, mate, and start next year’s migration north.