Caterpillar to pupa to chrysalis

Our monarch butterfly sanctuary is a dense stand of milkweed, over the years the established plants grow rapidly late May through June, blooming in July. The flowers have an incredible scent, attracting numerous pollinating insects.

A colony of pesky sparrows nest nearby. In spite of a reputation for tasting bad, the sparrow actively feed on the hatched caterpillars. My strategy is to examine the plants early morning, placing rescued caterpillars in this old birdcage.

Click photograph for a larger view and use Ctrl-x to zoom in closer.

The caterpillars and milkweed leaf is placed on the cage floor. I pile up the dried leaves, replacing with fresh each morning.

Sadly to report, the last, ravenous caterpillar stage is also carnivorous, cannibalistic. These two, below, were the only ones left except for one in the pile of dried leaves.

Here is a closer view of the two fifth stage instars searching for a safe location to pupate.

A few hours later one has successfully created a silk pad, attached itself and assumed the “J” shape. To the left a second caterpillar and silk pad.

The next morning, the first has formed a chrysalis. The second, hung spent.

This unsuccessful individual never completed the chrysalis, dried up and fell. My sources write the pupa transforms to a chrysalis through shedding of skin, the following photograph tells a different story. The chrysalis appears to extrude from the skin; arising over, or from, the skin rather and beneath it. I have never recovered a shed skin underneath a successful chrysalis.

Nine days later, Tuesday, July 28, the chrysalis hangs. I check several times a day.

These photographs are from a 100mm “macro” lens, handheld. The birdcage works well for protecting the monarchs. Is a poor location for photography.

Thank You for visiting.

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