> Dave Green wrote:

> When the spraying is done at night, or at least after the
> bees are done flying, there is no real hazard to the bees.

> By morning the dew has broken down the non-residual
> pesticide and it is no longer toxic.

Three problems with these comments:

Firstly not all agro-chemicals are broken down over an eight hour period. As a
matter of fact most of them need a much longer period of time. This means that
bees on flowers up to and including the residual toxicity period are at risk.

Secondly the break-down period of eight hours is normally extended because of the
moist and cool conditions of evening: to our knowledge dew does not assist in the
break-down of these substances - why spray with water as a carrier in that case?.
This implies that even an eight hour residual does not insure reduced bee death
risk.

Thirdly many agro-chemicals (or cocktails thereof) contain substances that induce
a repellency action. This was discovered in a plum orchard in Robertson near Cape
Town where not one single insect was visible in the orchards even though 20 hives
per hectare were placed. The problem was traced back to a spray application more
than a week before the bees were brought in. This has been repeated and proved to
be true on a number of occasions. The implication is obvious: no pollination, no
commercial crop..

As Bee Industry Association, we propose to our grower member that a "window" of at
least 48 hours is maintained totally spray fee before the bees are brought into
orchards.

As a matter of fact we also recommend that orchards are to remain totally chemical
free for the duration of the pollination period. A natural orchard is a happy and
stress free orchard for the bees.

I believe European law disallows any spraying on open flower ... something we
dream of.

  "Do you have flowers on your tobacco?"  I asked him.  "Of course not, only poor
farmers leave the blossoms."    "If there are no flowers, bees will not be present
in the field.  Go ahead. There is no problem."   He was relieved.

Again, sorry Dave, I would like to express a reservation here, that applies to us.
Perhaps not where you are. We often have, here in Cape Town, windy periods during
the pollination period. Spraying sometimes has to be done on orchards adjacent to
ones in which bees are working. Spray drifting happens. This is when spray from
adjacent (non flowering) orchards blows across to the target orchards' flowers.
This kills bees.

Spray drifting seems to be increased in the case of micro encapsulated products:
we believe that a static charge build up on the nylon material as it leaves the
nozzle. This causes mutual repellency, sending the capsules high up into the wind.
Bee and bird deaths have been noted 6 km further (not proven).

Robert Post