Reducing the Risk of Pesticide Poisoning to Honey Bees

 

Identify Yourself
The agencies involved in the mosquito spray program have an interest in keeping our honey bees safe.  You are encouraged to contact your local county Cooperative Extension office or your local county health department.  Let them know that you have colonies and are concerned about the dangers of the mosquito control spray program.  Be prepared to give information for locating your apiary or apiaries on a county map.  If the spray applicators don't know where you are, they may very well spray your hives.

Cover or Move Hives
The most practical and useful action for those concerned about bees being exposed to the mosquito spray is to cover their beehives.  This should be done with wet burlap or other breathable material.  The entire hive should be covered to prevent pesticide drift onto the hive.  It is especially important to cover the entrance to prevent foragers from going out to contact the poison in the air, on flowers or in water.  The material should be breathable to allow fresh air to penetrate, and damp to keep the colony from overheating.  In typical autumn weather, it is safe to confine a bee colony in this way for 2 days.
Though it may not be possible, moving beehives to a location where toxic pesticides are not being applied is another solution.  If you do move hives, be sure to move them at least a mile away to prevent bees from attempting to return to their previous location.
 
 

Time of Day
The pesticide applicators will be advised to spray near dusk, or twilight, because that is the time when adult mosquitoes are active and most vulnerable to pesticide spray.  Other advantages to spraying in the evening are that the cooler temperatures will keep the pesticide near to the ground where it will do the most good, and less windy conditions experienced in the evenings will reduce pesticide drift.  (The applicators will be advised not to spray if it is very windy).  Applications late in the day also allow the entire night and early morning for the poisons to decompose before honey bees begin to fly again the next day.  It is useful to know that most bee foraging stops when the wind exceeds 20 mph, or if the temperature is below 65 degrees F.
This evening spray is very good for beekeepers because the vast majority of bees will be inside the hive and not out where they could contact poisons in the air, on flowers, in water etc.

Formulation
Different formulations of the same chemical are different in their danger to honey bees.  In general, heavier formulations drift less and pose less danger.  Also, ground applications drift less and are safer than aerial applications.
a. "Dusts" almost always present the most drift problems of any pesticide formulation and are generally more dangerous to bees than are sprays or granular applications.
b. Spray formulations are usually safer to bees than are dusts but there are differences among the spray formulation types.  Generally water soluble formulations are safer than are emulsifiable formulations, and fine sprays are less dangerous than course sprays.
c. Granular applications are generally the safest formulations from a drifting standpoint and the accidental killing of bees.  This use should be considered if a granular formulation is suitable for destroying the target pest. Unfortunately, this formulation is not suitable for area-wide mosquito control.
Refer to the following chart if unsure about relative risks of various formulations:
 
FORMULATIONS IN ORDER OF INCREASING DANGER TO HONEY BEES; SAFEST TO MOST DANGEROUS
GRANULAR - ULTRA LOW VOLUME SPRAY - HEAVY WATER SOLUBLE SPRAY - FINE EMULSIFIABLE SPRAY - HEAVY EMULSIFIABLE SPRAY - DUST

 

Keep Informed
Information on mosquito spray programs may be listed in local newspapers, or on local radio and television programming.  Though you are undoubtedly concerned about your bees, remember that bees are just one consideration in the mosquito spray program.
 
 


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