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Pesticides and Honeybees

Pesticide use is simply a fact of modern farming.  If the best practices for the application of pesticides are used and the law is followed, the danger to honeybees can be minimized and managed.  However, too often the law is not followed and it’s the beekeeper who suffers.

So what can you do to protect your bees:

We strongly recommend you register through DriftWatch, but it is not the law. This site is a voluntary communication tool that enables crop producers, beekeepers, and pesticide applicators to work together to protect specialty crops and apiaries through the use of mapping programs. It is not a substitute for any state regulatory requirements.

Ohio law requires that you:

  • Register your apiary with the state.  Registration must be renewed every year by June 1st. This information is given to the pesticide operators when the call in to check for apiary locations. Without the information on this form, the applicator does not know who to contact and you may have no recourse if your bees are sprayed.  It is best to register an apiary as soon as possible instead of waiting for the June 1st date so the state has correct information. The application can be downloaded from the Ohio Department of Agriculture website.
  • You must post your name and phone number in every apiary.  It does not need to be a large formal sign and is only required to be visible when in the apiary.  It helps to post a sign close to the road so that applicators know that hives are nearby.

Ohio law requires the pesticide applicators give beekeepers a 24-hour notice of using a product that is labeled to be toxic to honey bees if the crop to be treated is in bloom and the field is greater than half an acre and within half a mile of any apiary (see rule below). This is not a lot of notice and given that you can only effectively close up hives at night, gives the beekeeper a very short period of time to protect their bees. Thus you must be prepared in advance to act on short notice. Having enough screen boards (used for moving hives) or double screen boards for at least one apiary is recommended. It also helps if you have screened bottom boards on your hives.

From the Ohio Revised code 901:5-11-02v1
(B) No person shall:

(15) Apply or cause to be applied any pesticide that is required to carry a special warning on its label indicating that it is toxic to honey bees, over an area of one-half acre or more in which the crop-plant is in flower unless the owner or caretaker of any apiary located within one-half mile of the treatment site has been notified by the person no less than twenty-four hours in advance of the intended treatment; provided the apiary is registered and identified as required by section 909.02 of the Revised Code, and that the apiary has been posted with the name and telephone number of the owner or responsible caretaker.

(16) Apply pesticides which are hazardous to honey bees at times when pollinating insects are actively working in the target area; however, application of calyx sprays on fruits and other similar applications may be made.


  • Before the spraying event, replace the inner cover with a screen board and elevate the telescoping cover or prop it up so as to give excess ventilation. Remove the sheet from the screened bottom board to allow for more ventilation. After the bees have returned for the evening or in the early morning before the bees begin flying, close all entrances. Duct tape or wooden blocks will work, but #8 hardware cloth is better to allow for ventilation. Make sure there is no hole big enough for bees to get out. This should allow enough ventilation so you can keep the bees in the hives for 2-3 days until after the major threat of pesticide poisoning has passed. On very hot days it would be wise to provide a water source in the hive (Boardman feeder) or periodically spray water in the hive to assist the bees cooling the hive.
  • Cover the hives with wet bed sheets
  • Sprinkler

You can also make sure that all the adjacent farmers to your apiaries know you have bees. The fact is, the beekeeper rarely will be notified of spraying, so notifying your neighbors and kindly reminding them of the law may be your best protection.

What to do if you suspect poisoning (it may not be a spray!):

  • Notify your local inspector to report the kill.
  • Take pictures of the hives and collect as much information as you can, e.g. when you last saw the colonies and they appeared to be healthy; personality of the colonies (actively flying, signs of nosema,etc.) direction of the wind, crops growing (or to be planted) in fields nearby; present activity of hives; dead drones? Dead pupae being kicked out?…etc.
  • Collect 50-100 bees in or on the bottom board and freeze asap. Do not collect bees that have been lying on the ground as they deteriorate quickly.  Leave ~ 100 bees for ODA to collect.  They may not take bees that you have already collected.
  • Contact the Ohio Department of Agriculture at Reynoldsburg Ohio. – 614-728-6373.   They should send someone to inspect the bees and collect samples for testing to determine what pesticide killed the bees.   They will also attempt to determine who was responsible for the pesticide spraying.   It could take 4 or more months to receive their report.   
  • Contact the EPA –
  • Report the kill to the Ohio State Beekeepers Association.  This information will help us bring the problem to the attention of the appropriate authorities.  Fill out the pesticide kill reporting form. Note: this form will sent also be sent to

So what about my dead bees?

If the hive dies completely you will need to buy more bees.  The state will not replace the bees. If they find the pesticide applicator responsible they may fine or in repeat cases revoke the applicator’s license. The state cannot obtain compensation for your bees. You will be required to take the applicator to court and sue for damages. The state will provide you with their findings which you can use in court and may testify on your behalf as to the findings.

In addition, if the bees die out, you may want to air out the frames and foundation in a building. After a week or more (otherwise, the foundation may mold),  but the equipment in storage and not use it again until you receive the report from the state. Hopefully, the pesticide breaks down quickly so the equipment can safely be reused. If the pesticide the state identifies does not break down quickly, the equipment may still be toxic and could pose problems for any bees you place in the equipment. In this case, the equipment must be destroyed.