Monarch Caterpillars, Milkweed and WWII


There has been much concern about the dwindling  numbers of Monarch Butterflies.  An organization called Monarch Watch has been encouraging everyone to plant Milkweed, also know as Butterfly Weed.

I have been planting Butterfly Weed all over the yard.  Unfortunately, a beetle has shown up the last few years and has eaten almost all the plants I grew.  This year I am trying to collect the bugs daily for disposal, as any kind of spraying will also kill the Monarchs.

I was pleased to find many very fat and healthy Monarch Caterpillars on the Butterfly Weed.  This one is eyeing his competition.


My main purpose for planting Butterfly Weed is to feed caterpillars.  The plants tend to look pretty bad after awhile.  Interestingly, the plants contain a chemical called cardiac glycoside that cause birds to vomit.  By eating the leaves, the caterpillars are protected from birds.

I find that rabbits and deer also avoid the plant. The most common Butterfly Weed grown here is Asclepias tuberosa, which is tropical/Mexican Butterfly Weed.

The plants produce seed pods filled with seeds attached to fluffy floss that allows them to drift in the wind to a new location.

I recently found out that Milkweed floss had an important role in World War II.  School children from all over the country were sent out to collect the seed pods to make life vests for Navy sailors. Milkweed in the northern U.S. is much larger than the ones that grow in the South and were found growing in fields and along the roads.  The seeds were removed and the floss was used to stuff the vests.

I find it hard to imagine that these vest would stay afloat for long, but I guess that is what they had back then.  While researching, I also found an article with instructions for making a down-like coat using the Milkweed floss for the insulation.  As it turns out, this “weed” is not only necessary for Monarchs, but humans have also found uses for it.