The number of monarch butterflies wintering in Mexico plunged this year to its lowest level since studies began in 1993, leading experts to announce recently that the insects’ annual migration from the United States and Canada is in danger of disappearing.
A report released by the World Wildlife Fund, Mexico’s Environment Department and the Natural Protected Areas Commission blames the displacement of the milkweed the species feeds on by genetically modified crops and urban sprawl in the United States, as well as the dramatic reduction of the butterflies’ habitat in Mexico due to illegal logging of the trees they depend on for shelter.
After steep and steady declines in the previous three years, the black-and-orange butterflies now cover only 1.65 acres in the pine and fir forests west of Mexico City, compared to 2.93 acres last year. They covered more than 44.5 acres at their recorded peak in 1995.
Experts say that this is now a statistical long-term trend and can no longer be seen as a combination of yearly or seasonal events.
The main culprit now is GMO herbicide-resistant corn and soybean crops and herbicides in the United States, which leads to the killing of the monarch’s principle feeding plant, the common milkweed. Another problem is logging in Mexico. Slowly there is headway on reducing the logging in this critical habitat. There are also other factors, such as weather, heavy rains, and droughts that have played a role in the decline.
The migration is an inherited trait. No butterfly lives to make the full round trip, and it is unclear how they remember the route back to the same patch of forest each year, a journey of thousands of miles to a forest reserve that covers 193,000 acres in central Mexico.
What can you do as a gardener to help?
First off, planting those plants with nectar and also plant milkweed. Milkweed should be planted in every yard. Place some plants amongst your flowers and also vegetable garden. If you have a large area, devote a lot of space into a milkweed plot. The Monarch Watch website has an extensive list of shrubs, cultivated annuals, cultivated perennials and wild perennials. Check it out: http://www.monarchwatch.org/garden/nectar.htm. Instead of growing plants with no pollinator value, find out what monarchs and other pollinators love. Reducing the mowing of ditches and other acreage and having less lawn and more pollinator friendly plants are all steps in the right direction.
Here are some resources to get the plants and seeds: Busse gardens (bussegardens.com), Cheap Seeds (cheapseeds.com), Landscape Alternatives, Inc. (landscapealternatives.com), Morning Sky Greenery (morningskygreenery.com) Prairie Moon Nursery (prairiemoon.com), Prairie Restoration, Inc. (prairieresto.com). Be sure you get the best plants or seeds for your area by purchasing from near to where you live.
Milkweed seeds can be sown outdoors after the danger of frost has passed. Refer to the seed packets for special instructions on sowing the seeds. Keep in mind that seeds have a range of soil temperatures at which they will germinate. Also, remember that under sunny conditions the soil temperatures can be much higher in the daytime than the ambient air temperatures you experience. Plant the seeds early since those planted late in the season may not germinate because of high temperatures. In addition, new seedlings from late plantings can “dry off” before they are even noticed. Asclepias incarnata (swamp milkweed) and A. syriaca (common milkweed) germinate poorly at high temperatures (85˚F). However, other species, such as A. curassavica (tropical milkweed) and Cynanchum laeve (blue vine), germinate well at these temperatures. Germination outdoors depends on soil moisture and temperature and can take several weeks if conditions are not ideal.
Most milkweed species evolved in open areas where they were exposed to full sunlight and they will do best if they are planted in the sunniest areas of your gardens. A few species, such as A. purpurascens, appear to require partial shade. Check your seed or plant labels carefully. Monarch numbers will rebound but only if weather allows and there is enough milkweed to increase the population.
With everyone doing their part we may be able to help a little by saving the monarchs. If not we may lose them all together.
Keep those questions and comments coming by sending to rcschlueter@yahoo.com.