Jonathan Ruel wrote:

> How can I allow my bees entrance to the greenhouse but exclude grasshoppers?

Good day

We do quite a bit of greenhouse pollination, mainly on melons and other
cucurbits.

There are two tricks, employing the same principle.

The first method requires a special piece of equipment: a two-way floor.
One entrance front and one at the back. One entrance inside and the
other outside. The object is to have more than one hive placed inside
cut-outs in the greenhouse wall (easy if made from plastic materials).
Tape the edges of the greenhouse material to the outside of the hive
to stop anything else from entering, retaining sterility or other
environmental factors. Then alternate the entrances by closing and
opening each entrance on each hive alternatively: one hive inside
for a week, the other outside for that week, then reverse the entrances
for another week and back again. This mainly to ensure that sufficient
food is collected (from outside) to retain a growth phase within the
hive for efficient pollination inside the dome.

Second option is just to have both entrances at the front. In other
words a spacer block in the centre of the entrance divides the
opening into inside and outside access. The hive is then placed
side-on in the cut-out in the material wall.

Greetings

Robert Post