The aerial permethrin pesticide used by Cass County Vector Control led by Ben Prather is Perm-X UL 31-66. According to this product’s Specimen Label Sheet, “This pesticide is highly toxic to bees exposed to direct treatment on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops or weeds while bees are actively visiting the treatment area” and “Applications during the cool hours of night or early morning are usually preferable.”


Bees and butterflies are active for up to two hours after sunset. In order to protect pollinators from aerial or truck mounted pesticide spray, many cities have gone to dusk and night spraying. This would put the aerial spray start time several hours later than the approximate 7 p.m. starting time of the aerial spraying that precipitated the “Monarch Massacre” or truck mounted spraying that often starts at about the same early hour of 7 p.m.

Other cities also use targeted application of pesticide only with confirmed cases of actual mosquito West Nile virus - not just the discovery of uninfected mosquitoes of a particular species. Targeted applications involve ground based applications such as truck mounted spraying. At the time of the Monarch Massacre in late August, Prather complained he was forced to go to aerial spraying due to his staff of college students having gone back to school. With an enormous budget unrivaled by most cities in our region, Prather seems unable to solve a staffing problem to protect our ecology resulting in a PR disaster as children wept at the sight of streets and sidewalks covered with dead butterflies.

Prather is a brilliant man and I’m sure he’s planning to improve on his performance during the coming mosquito season. I sincerely hope that a chorus of voices will demand:

  • Confirmation of actual West Nile virus infection before spraying.
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  • Targeted ground based spraying long before aerial spraying is considered with proper staffing to implement it.
  • Starting any pesticide spraying after dusk and into the night to protect pollinators.

The next Vector Control Meeting is March 3rd.

Joseph Allen lives in Moorhead.

This letter does not necessarily reflect the opinion of The Forum's editorial board nor Forum ownership.