Mosquito Control and Bees 

Since the spray programs for adult mosquitoes may leave residues that are toxic to bees for one to two days after the initial spray, which typically takes place at night, beekeepers may want to take steps to protect their bees.

·        Contact your local health department to find out if there is a spray   
      program in your area.

·        Move your bees out of the spray area the day before the spray and bring them back a few days after the spray is completed.  Be sure you do not move them from one spray area to another.

·        Confine your bees to their hives for a day after the spray.  You will have to confine your bees the night before the spray takes place, and leave them confined for 24 hours.

To confine bees to a hive, screen off the entrance with 1/8” hardware cloth, plug or tape all other holes in your equipment that the bees are using as entrances, and replace the inner and outer covers with 1/8” hardware cloth screen, covered with two layers of wet burlap. Keep the burlap wet while the bees are confined. Place a sheet of plastic loosely over the burlap during the night of the spray to minimize direct contact with the pesticide, but removing it in the morning.  If your bees are in the sun, you must provide shade. A day of confinement is all that a colony can take without suffering significant damage, especially if it is hot.

·        If you choose to leave your colonies unprotected in the spray zone, observe the entrances for several days after the spray takes place. If you note an unusual number of dead, crawling or dying bees in front of your hives, call your regional DEC office and ask that a Pesticide Specialist come and sample your bees to determine if the kill is due to pesticide.

·        For extensive information on West Nile Virus, control methods of the virus, and the various pesticides being used as part of the control methods visit the New York State Department of Health website at www.health.state.ny.us/

·        To locate phone numbers for your regional DEC office visit the DEC website at www.dec.state.ny.us/

Excerpt from correspondence from Nicholas W. Calderone, Cornell University, Department of Entomology.

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