Significant Drop in Monarch Butterfly Population Linked to Loss of Milkweed Plant: Study

Guelph, Ontario – Those who are inspired by the majestic beauty of the monarch butterfly will be hard pressed to see many this year. A report out by scientists at the University of Guelph suggests that the monarch butterfly population across all of North America may decline by as much as 90%. This is a dramatic decline.

While there are various contributing factors to their decline, the salient reason is the decline of milkweed crops. The flowery herbaceous perennial known for its milky juice is a mainstay for the monarch butterfly. Milkweed serves a number of medicinal purposes, but crops of the plant have been declining leaving the butterfly with diminished breeding grounds.

Professor Ryan Norris, a member of the research team, says the report is the first of its kind to prove that there is a direct link between milkweed plants and the monarch butterfly. The problem is most acute in America’s heartland of the Midwest.

“We’re losing milkweed throughout eastern North America, but what we found out is milkweed loss specifically in the midwestern U.S. is likely contributing the most to monarch declines,” he said upon the study’s publication Wednesday in the Journal of Animal Ecology.

Corn growers are using pesticides to wipe out the milkweed to clear space for corn, but it is the detriment of the monarch butterfly population.

The report claims that over the 18 year period from 1995 to 2013, industrial farming led to a 21% reduction in the milkweed plant population in areas known to be the monarch butterflies primary breeding grounds.

The problem is that monarch butterflies only lay their eggs on milkweed plants. The eggs then hatch and give rise to monarch caterpillars which likewise only feed on the milkweed plant. This year alone, the population has declined by 90%. This was evident in Mexico where the population has decreased from 350 million to an estimated 33.5 million or nearly 96% decline. Mexico is now making conservation efforts to protect the breeding grounds of the butterfly. It will likely take conservation efforts in the United States as well.

Photograph of the Monarch Butterflyen (Danaus plexippus en ) on a Purple Conefloweren (Echinacea purpurea en ). Photo taken at the Tyler Arboretum. Camera and Exposure Details: Camera: Nikon D50 Lens: Sigma 70mm f/2.8 EX DG Macro Exposure: 70mm (105mm in 35mm equivalent) f/11 @ 1/100 s. (200 ISO)

Photograph of the Monarch Butterflyen (Danaus plexippus en ) on a Purple Conefloweren (Echinacea purpurea en ). Photo taken at the Tyler Arboretum. Camera and Exposure Details: Camera: Nikon D50 Lens: Sigma 70mm f/2.8 EX DG Macro Exposure: 70mm (105mm in 35mm equivalent) f/11 @ 1/100 s. (200 ISO)

Source:

http://www.thestar.com/news/canada/2014/06/04/monarch_butterfly_decline_due_to_loss_of_milkweed_new_study_shows.htm



Sean is a London (Ontario) based writer, and has been writing full-time for eCanadNow since May of 2005, covering Canadian topics and world issues. Since 2009, Sean has been the lead editor for eCanadaNow. Prior to his work writing and editing for the eCanadaNow, he worked as a freelancer for several Canadian newspapers.. You can contact Sean at {Sean at ecanadanow.com] Google

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