Why We Are Concerned…
A Bit of Background
Milkweeds and nectar sources are declining due to the development and the widespread use of herbicides in croplands, pastures and roadsides. Because 90% of all milkweed/monarch habitats occur within the agricultural landscape, farm practices have the potential to strongly influence monarch populations.
Development (of subdivisions, factories, shopping centers, etc.) in the U.S. is consuming habitats for monarchs and other wildlife at a rate of 6,000 acres (9.4 square miles) a day - that's 2.2 million acres each year. This is roughly equivalent to losing an area of habitat the size of the state of Illinois (the 24th largest U.S. state) every sixteen years!
Widespread adoption of herbicide-resistant corn and soybeans has resulted in the loss of more than 100 million acres of monarch habitat in recent years. The planting of these crops genetically modified to resist the non-selective systemic herbicide glyphosate (Roundup) allows growers to spray fields with this herbicide instead of tilling to control weeds. Milkweeds survive tilling but not the repeated use of glyphosate. This habitat loss is substantial since these croplands represent a significant portion of the summer breeding area for monarchs.
The use of herbicides and frequent mowing along roadsides has converted much of this habitat to grassy areas that lack shelter and food for wildlife. Although some states have started to increase the diversity of plantings (including milkweeds) along roadsides, these programs are small. Unfortunately, the remaining milkweed habitats in pastures, hayfields, edges of forests, grasslands, native prairies, and urban areas are not sufficient to sustain the large monarch butterfly populations seen in the 1990s. MONARCHS NEED OUR HELP. Credit; Monarch Watch.