the barn in fall

the barn in fall

Thursday, June 30, 2011

Milkweed and Monarchs

The green theme on this page is a bit overwhelming, but here's more chlorophyl for you - a post about another weed I allow to thrive in my pasture: milkweed.

Horses don't like milkweed any more than they like those daisies in my previous post.  But monarch butterflies do.  In fact, monarchs need milkweed.  (Brace yourselves; science Googling ahead.)  They lay their eggs on the plant, the caterpillar larvae feed on the plant, they form their coccoons there, and the butterfly sips its nectar, along with a few other flowers.  In fact, the butterflies even gain a unique protection from eating milkweed as larvae - they take in cardiac glycosides, which makes them taste bad and is poisonous to birds.  (I don't know how, but I'm guessing the cardiac part is a clue.)

Monarchs migrate, the only butterfly that does.  Last year storms in Mexico killed many of the butterflies.  It takes 2 or 3 generations for the surviving monarchs to get this far north, but I haven't seen a single monarch yet, and this is when they should be here.  (Have you?  Let me know!)  For those who make it, I've got a smorgasbord of milkweed waiting in my pasture.

2 comments:

  1. Just a small correction, "lay their eggs on the plant, the caterpillar larvae feed on the plant, they form their "chrysalis" there, and the butterfly sips its nectar, along with a few other flowers."

    If it comes out of a cocoon it is a moth, not a butterfly.

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  2. Thanks, I thought chrysalis was the scientific way to say cocoon. It sounded stilted, so I changed it. Bad move!

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