Why should beekeepers trap wasps in spring?
The problem I am hoping to address happens in autumn which is a squadron of yellow jackets attacking your weakest colony of honeybees. You can mitigate the problem by narrowing the hive entrance to one bee-space.

If the wasp-attack is still persistent, place a clear material at the front of the hive. The idea is that those silly wasps will fly head-on into the clear material, but the honeybees will go around it to get to the hive entrance. In my experience the wasps also figure out how to go around the clear material.

The other remedial measure is to put wasp traps out in August. Put jam in the bottom of a bottle and the wasps get in but can’t get out. If it’s a bad season and there is a plague of wasps, the traps will reduce numbers but won’t solve the problem.
Wasp Queens in Spring
If you place wasp traps out in spring, then there is a good chance of trapping the queen wasp. Reducing the numbers of queens dramatically reduces the number of wasps later in the year.
Earlier this year I moved apiaries and didn’t get around to putting out wasp traps. I paid the price later in the year and the wasp-plague descended on the apiary in the autumn.
In previous years I used plastic fizzy-drink bottles for wasp traps. This year I experimented with plastic buckets and put a Canadian bee escape at the top. I can’t recommend the latter method because the wasps didn’t want to go inside the trap.

Next spring I will be putting out traps and trialling purpose made ones which I have seen at Freeman and Harding. Watch this space to see how well I got on.
To conclude, put out trap wasps in spring and reduce wasp numbers in autumn.
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