PASCO, Wash. As a little girl, I can remember watching a green chrysalis turn into a beautiful monarch butterfly.
The distinctive orange and black monarch butterfly (Danaus plexippus) migrates each year from northern areas east and west of the Rockies to spend the winter in Mexico and along the California coast. There are two different groups or populations of monarchs, the eastern population breeds in the east and overwinters in Mexico and a few of the warmest southern U.S. states. The western population breeds in the west and overwinters in sunny California.
East or west, it's only one generation of butterflies that flies south in late summer, some traveling as many as 3,000 miles, but it takes three or four generations of the butterfly to make the return trip all the way back to the northern U.S. and Canada each year.
To enable this long trip back, the multiple generations of monarchs depend on milkweed they find along the way. Adult butterflies feed on the nectar of milkweed and other flowers, but monarch larvae feed only on milkweed. Without milkweed, they can't reproduce.
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Because of threats to its milkweed habitat and overwintering sites, there is concern for the monarch butterfly. While not yet an endangered species, monarch enthusiasts are worried because the monarchs aggregate in large populations in a limited number of sites when overwintering in Mexico and California. This makes them particularly vulnerable to logging, development, agriculture and other human activities.
There also is concern about the loss of milkweed habitat in this country, as well as the possible toxic effects on monarch populations from the pollen of genetically modified corn.
While USDA researchers at the Agricultural Research Service's Research Unit in College Station, Texas, were researching a better chemical lure to trap boll weevils, a serious pest of cotton, they discovered a lure that is attractive to milkweed stem weevils. Stem weevils are a major milkweed pest. This serendipitous discovery will be used to develop a trap that will help scientists monitor the movements of the stem weevils and protect the prized monarch's milkweed habitat.
Home gardeners can help, too. The Monarch Joint Venture (MJV) is a partnership of federal and state agencies, nongovernmental organizations, and academic programs that are working together using a science-based approach to protect the monarch butterfly. They note that changing land management practices has led to a loss of native milkweed. The MJV is urging home gardeners to plant milkweed in their gardens.
Monarch Watch, a volunteer group of monarch and milkweed advocates, recommends planting milkweeds native to the region in which you live. They have identified the common species of milkweed that are found in different regions of the U.S., that are used by monarchs during their migrations, and that are easy to establish. A list of these milkweed species can be found on the Monarch Watch website (www.monarchjointventure.org/Milkweed/Milkweed-info-sheet.pdf).
Planting regional milkweed species is "easier said than done" because you can't find packets of milkweed seed at any garden store.
To help you find sources of regional milkweed seeds and plants, Monarch Watch also has put together a list of vendors for each region. (http://monarchwatch.org/bring-back-the-monarchs/resources/plant-seed-suppliers)
You can be part of the effort to protect the awesome monarch butterfly, by planting some milkweed in your garden and by learning more about the attempts to protect it.
* Marianne C. Ophardt is a horticulturist for Washington State University Benton County Extension.