The problem appears to be that the butterfly cannot find enough food. Monarchs are picky eaters. The monarch caterpillar appears to feed on one plant, and only one plant: milkweed. Corn and soybean fields used to share rows with milkweed plants, providing ample food for monarchs. Then came Roundup Ready crops. These plants can withstand a regular dosing of Roundup, but the milkweed they shared the land with cannot. So, milkweed is becoming a rarity in the Midwest and so is the iconic butterfly.
Stories like this have become all too commonplace. Infested pallets bring the emerald ash borer, which in turn decimates Michigan forests. Zebra mussels in ballast water end up devastating the Great Lakes fishery. People are having an outsized effect on the environment. Nature is all akilter, and even the main stream media is sharing the news.
The good news for those who love the monarch butterfly, is that there is something you can do to help them survive. Plant milkweed. Tuck it into your flower garden; plant it between rows in your veggie garden. Heck, plant an entire milkweed garden—there are various kinds of milkweed, and the subtle variations can make an attractive bed.
There’s been a growing movement among gardeners that champions the planting of native plants. In the past, imported species were prized, for the exoticness, but also because regional insects didn’t find them edible. Native plants, however, help sustain local insect populations, which in turn feeds birds and others on up the food chain. This is good for the environment and native plants can withstand some predation.
So, when you head out to clear space for your milkweed, but sure it’s a native to the Midwest. Monarch caterpillars don’t eat foreign food. And, also, try and find plants that have not been treated with a systemic pesticide. These chemicals make the milkweed poisonous to butterflies, and that sort of defeats the purpose.
* “Monarch butterflies losing their food source, numbers declining sharply”