Monthly Science: Raising a Monarch Butterfly

A Monarch butterfly laid eggs in late July. On the 29th of July they looked like this:

Monarch Egg - focus stacked
Monarch Egg – focus stacked

By August 2, a pair of caterpillars had hatched and grew to 3 mm:

Monarch caterpillar - 3 mm - 2017-08-02
Monarch caterpillar – 3 mm – 2017-08-02

A day later, they were 4 mm long:

Monarch caterpillars - 4 mm - 2017-08-03
Monarch caterpillars – 4 mm – 2017-08-03

They really were sort of blue-ish with green hints:

Monarch caterpillar 1 - 4 mm - 2017-08-03
Monarch caterpillar 1 – 4 mm – 2017-08-03

And:

Monarch caterpillar 2 - 4 mm - 2017-08-03
Monarch caterpillar 2 – 4 mm – 2017-08-03

By August 9, one had had more mature coloration:

Monarch caterpillar - 2017-08-09
Monarch caterpillar – 2017-08-09

The other caterpillar had vanished; we assume it got out of the aquarium and wandered off.

Apparently, the front end of the caterpillar (at the bottom of the picture) has a hard windshield reflecting the ring of LEDs around the camera lens. The caterpillar eats its skin after each molting, except for the windshield:

Monarch Windshield - 2017-08-09
Monarch Windshield – 2017-08-09

We kept fresh milkweed branches in a vase and the caterpillar ate almost continuously:

Monarch caterpillar - 2017-08-13
Monarch caterpillar – 2017-08-13

By August 15, the caterpillar was ready for the next stage in its life. At 10 in the morning it had attached itself to the screen covering the aquarium and assumed the position:

Monarch caterpillar - starting chrysalis - 2017-08-15
Monarch caterpillar – starting chrysalis – 2017-08-15

It transformed into a chrysalis by 5:30 PM:

Monarch Chrysalis - with skin
Monarch Chrysalis – with skin

The discarded skin remained loosely attached until I carefully removed it.

What look like small yellow spots are actually a striking metallic gold color.

Eleven days later, on August 26 at 9 AM, the chrysalis suddenly became transparent:

Monarch chrysalis - ready - left
Monarch chrysalis – ready – left

And:

Monarch chrysalis - ready - right
Monarch chrysalis – ready – right

The shape of the butterfly becomes visible in reflected light:

Monarch chrysalis - ready - ventral detail
Monarch chrysalis – ready – ventral detail

The gold dots and line remained visible.

The magic happened at 3 PM:

Monarch chrysalis - emerging - unfolding
Monarch chrysalis – emerging – unfolding

The compacted wings emerge intense orange on the top and lighter orange on the bottom:

Monarch unfolding - left
Monarch unfolding – left

The butterfly took most of the day to unfurl and stiffen its wings into flat plates:

Monarch unfolding - dorsal
Monarch unfolding – dorsal

And:

Monarch unfolding - right
Monarch unfolding – right

By 8 PM it began exploring the aquarium:

Monarch unfolded - right
Monarch unfolded – right

As adults, they sip nectar from flowers, but don’t feed for the first day, so we left it in the aquarium overnight.

At 10 AM on August 27, we transported it to the goldenrod in the garden, where it immediately began tanking operations:

Monarch on Milkweed - left
Monarch on Milkweed – left

A few minutes later, it began sun-warming operations:

Monarch on Milkweed - dorsal
Monarch on Milkweed – dorsal

Mary watched it while she was tending the garden and, an hour or so later, saw it take off and fly over the house in a generally southwest direction. It will cross half the continent under a geas prohibiting any other action, eventually overwinter in Mexico with far too few of its compadres, then die after producing the eggs for a generation beginning the northward journey next year.

Godspeed, little butterfly, godspeed …

In the spirit of “video or it didn’t happen”, there’s a 15 fps movie of the emergence taken at 5 s/image.

4 thoughts on “Monthly Science: Raising a Monarch Butterfly

  1. Very nice Ed. We have not taken up rearing anything so far but rescue a number of critters every year. As for monarchs, we have seen several that emerged and the wings never fully flattened out. Some could fly, others never made it. Some sort of defect in the matrix I guess, rather sad after having made it so far too.

    1. Many decades ago, we hatched a Luna moth in a too-small container where it couldn’t spread its wings; I still feel badly about that episode.

      1. Understood and appreciated. It’s hard to shake certain things like that, and I can relate.

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