Pesticide Exposure Is a Known Risk in Pollination Service

Colonies placed in agricultural fields during pollination are in proximity to active crop management operations. Pesticide applications by growers, by adjacent landowners, and by other pest management contractors occur in the same environment where your bees are foraging. Protecting colonies from exposure and having a clear response protocol when exposure occurs is a core operational requirement for commercial pollination operators.

Prevention Through Contract Language

The first line of protection is what your contract says. Standard commercial pollination contracts require growers to provide 48-hour advance notice before any pesticide application within a specified distance of hive placements. This notice requirement gives you time to close entrances and move hives before a high-toxicity application. Contracts should also specify that the grower is responsible for coordinating with adjacent landowners who might spray near your placement area, since off-target drift is a real source of exposure events.

Review your contract's pesticide provisions before signing each season. California has specific requirements under CDFA regulations; other states have varying standards. In California, growers are required by law to notify beekeepers before pesticide applications when hives are registered at the county level. Make sure your hives are registered so that legal notification requirements apply to your placements.

High-Risk Materials

The most toxic materials for honey bees fall into several categories: insecticides applied during bloom (particularly neonicotinoids, pyrethroids, and organophosphates), fungicides applied to almond during bloom that can synergize with other pesticides to increase toxicity (notably propiconazole and tebuconazole-based products), and herbicides that kill wildflower forage adjacent to placements. Stay current on the materials approved for application near pollinators in each crop where you have placements.

Recognizing and Documenting Exposure Events

Pesticide exposure presents as sudden, large-scale adult bee mortality at the hive entrance, often with dead bees crawling in circles or exhibiting neurological symptoms. This differs from a normal daily dead bee pile in magnitude and in the visible symptomology. When you suspect exposure: photograph the hive entrance and the pile of dead bees with a date-stamped camera, collect a dead bee sample (at least 100 bees in a sealed container stored frozen), document the weather conditions and wind direction, and contact the grower immediately to determine what was applied and when.

Dead bee samples can be submitted to a state laboratory for pesticide residue analysis. This analysis takes several weeks but provides documented evidence of specific compounds, which is necessary for insurance claims and for any dispute with the grower. PollenOps event logging lets you record exposure events with timestamps, photo documentation, and notes, creating an evidence trail from the moment of discovery through resolution.

Recovery Management

After a significant exposure event, assess every colony in the affected yard within 24 to 48 hours. Document population loss, brood condition, and any queen issues resulting from forager loss. Colonies that survived but lost significant forager population may need emergency feeding and should be considered for replacement before delivering on a subsequent contract commitment if they cannot recover to minimum strength in time.