a first test
The location of your hives is kept a secret to you, so your security is assured. You will receive an email alert detailing timing, distance and direction of the spraying event, also the name of the active ingredient to be used and the basic descriptive information as published in the British Crop Production Council Pesticide Manual including any environmental protection precautions relevant to bees. Included also will be the crop to be sprayed (e.g. field beans) and whether the field to be sprayed has a flowering margin next to the crop. The farmer only knows there are hives within a given radius, e.g. 5km. There is also an email service which enables the beekeeper to contact the farmer should they wish to ask a question.
Putting large amounts of straw or grass in front of the hive to cover and obscure the entrance occupies the bees while they tear it down. They do this without building up heat and tend to stay calm during the process, it occupies the workers and they tend to stay around the hive for quite some time so they don’t go off foraging.
Tenting, covering hives with black plastic, turning day into night can also work, but don’t restrict airflow, and allow the bees to leave if they want. It’s probably best not to leave the hive covered into the warm summer sun as the colony may overheat.
The danger of overheating is great so this should only be done in extreme circumstances and the hive should be closed up for as short a time as deemed necessary. Provide extra space by placing additional supers with comb onto the hive to contain temperature rises. Completely block the entrance so as to stop all light entering the hive. Shade the hive to stop sunlight raising the internal temperature of the colony. Keep the temperature rise to a minimum. Open the hive as soon as the spraying event is finished. DO NOT LEAVE THE HIVE CLOSED FOR LONGER THAN 24 HOURS IN THE SUMMER.
Move your bees away from the spraying event but this might not be practical and don’t forget the three-mile rule.