Salem Mayor Chuck Bennett has signed a proclamation to join the U.S. Fish and Wildlife Service and the National Wildlife Federation’s Mayor’s Monarch Pledge to work to address the rapid loss of the monarch butterfly.
The monarch has faced sharp population declined – 90% since the 1990s – because of habitat loss from urbanization and the use of pesticides and herbicides.
The City of Salem has put out information since the December 2017 proclamation, to let people know how chemicals wipe out monarchs by killing both the beneficial insects and the milkweed plant which they have evolved to co-exist with.
Milkweed is essential to monarchs since they use it exclusively to lay their eggs on and since their caterpillars use it exclusively to feed on.
Prior to 1990, native milkweed often grew in rural gullies and along roadsides, or sprang up between rows of commercial crops like corn or soybeans. But since then the number of farmers planting herbicide-resistant crops have burgeoned; these crops allow the spraying of fields with powerful chemicals such as Roundup – which milkweed cannot survive.
Numbers of butterflies have plummeted. In 1996 they used 21 hectares of Mexican forest in their seasonal migration; now they use less than a hectare.
It’s important for Mid-Willamette gardeners who want to support milkweed to plant native milkweed species and NOT tropical milkweed (Asclepias curassavica) which may be harmful to the butterfly.
The Mayor’s pamphlet describes the effects of urbanization on the monarch, saying, “residential properties make up approximately 47% of the urban landscape in Salem, meaning there are fewer areas suitable for monarchs to use during their 2,500-mile migration.”
Bennett’s pamphlet suggests several steps people can take. The first is to plant native milkweed in local gardens, yards, and neighborhoods, to add nectar-producing plants such as blueblossom and sunflowers to yards and to limit pesticides and herbicides in Salem yards and gardens.