As a beekeeper here in the Niagara Peninsula I share and understand this
situation.
Commonly guthion and other sprays have been used . Spraying is always done
after the blossoming and then Sevin is commonly used as the apples develope
when the producer wishes to thin the apples on the trees. This is a delicate
spraying situation that if the concentration is not perfect will cause complete
crop loss or a very poor crop.
Obviously if there is a residue in such an amount that bees can pick it up
then the people spraying it no nothing about what they are doing and need to
be educated not only from the toxicity standpoint but also the contamination
aspect of the surrounding area.
I feel the beekeeper is obligated to discuss spraying habits with the
property owner where bees may be affected simply as a measure of insuring the
safety of ones own bees.
A good farmer will spray only when weather conditions are right and most do
it early morning well before the bees fly so that the spray dries
appropriately
. At one point I covered my bees for the interm since weather conditions
forced a change of scheduling and wind direction was not favourable for the
spraying to take place.
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