Pollinators, mainly insects such as bees, butterflies, wasps, and flies, are essential for the survival of most flowering plants and are necessary for growing more than 50 major crops. Biting insect control is important due to the nuisance they cause and their potential for being vectors for severe human disease.
Minimizing pesticide exposure to non-target species is a high priority for the OCW. To protect honeybee colonies and other pollinators from possible pesticide exposure, there must be effective communication and cooperation between beekeepers and the insect control district.
The OCW realizes that at times it may be necessary to control adult mosquitoes in areas known to have bee colonies. Because bees and other pollinators are most active between sunrise and sunset, the OCW adult mosquito treatment schedule does not begin until after sunset – well after when most bees have returned to their hives. Note also that a significant portion of OCW operations are for control of mosquito larva. Larvicide is applied directly to standing water and therefore does not affect pollinators at all.
To control flying adult mosquitos the OCW uses truck mounted Ultra Low Volume (ULV) sprayers. Annually those ULV sprayers must be tested to ensure that they are properly calibrated and produce a fog that meets the (EPA-approved) pesticide manufacturer’s specifications for spray rate and a droplet size volume median diameter < 30 microns with 90% of droplets < 50 microns. At this small size the droplet is designed to impact mosquito sized insects, not much larger insects such as butterflies, bees, or beetles. Also, the chemical formulation the OCW uses is a contact insecticide, selected because those chemicals, once released, break down rapidly, before bees and other pollinators begin to forage the next morning. The spray plume is narrow, typically 300 feet wide (150 feet either side of the truck) but depends on wind direction and speed.
Best Management Practices for Beekeeper / Mosquito Control interaction:
– If possible, locate hives 300 or more feet from roads that will be treated. See the Route Maps tab on this website for details about which roads the OCW treats for adult mosquitos.
– Before April 15th annually, request No Spray Zone status due to the presence of bees. See the Adulticide tab on this website for additional details.
– Report any colony movement (changes in location) to mosquito control by calling (802) 247-6779 or emailing firstname.lastname@example.org.
– Beekeepers are responsible for managing the health of their colonies; healthy hives are less susceptible to disease or possible damage from pesticides.
– After receiving a No Spray Zone request, OCW employees will mark the property with specially marked stakes alerting our pesticide applicators that they are approaching an apiary.
– Pesticide applicators will turn off the truck sprayer before reaching the specially marked stake and will leave the sprayer off until past the marker stake at the other end of the No Spray Zone.
– At least four hours in advance of spraying, post on the OCW website Public Notice tab the route(s) to be sprayed and the pesticide(s) to be used.
– All truck mounted spraying will be done when bees are not flying, i,e, sunset to sunrise.
– Pesticide applicators will monitor wind direction to prevent unwanted spray drift towards colonies.
– Pesticide applicators will avoid direct application of spray to flowering plants, whenever possible.