When we talk about “pollinators” or “wildlife,” honeybees and monarch butterflies are two species that people seem to have heard the most about. Even people who don’t garden know that both species are in trouble and that efforts are being made to help each.
In the last couple of months, however, a couple of interesting things about the monarch and the ways people try to help them have come out. Today and Monday I will look at each one–trying not to get controversial about it–so that people can be informed.
Today I want to look at ascelepias–milkweed. We know that monarch butterflies need to lay their eggs on the milkweed plant and their caterpillars need to eat milkweed in order to live.
So in order to help the monarchs, gardeners have been encouraged to plant milkweed, and here’s where the problem begins.
As you might already know, there are many different varieties of milkweed. They are all asclepias, but depending on the variety, they can be “native” or “tropical.” And that’s where the problem began.
In some parts of the country, the tropical variety, asclepias curassavica, is more “common,”–or at least more readily available–than native varieties so gardeners planted those. (It didn’t help that a. curassavica is really pretty.)
Unfortunately caterpillars that feed on tropical milkweed are also eating fungal spores. They pass these on to migratory butterflies on their way up from Mexico and the population is weakened in the process.
It’s a lot more complicated than I have made it seem here. To read an in-depth study by the Xerxes Society, go here.
The takeaway from this: when it comes to asclepias, native really is best.