Where the Bees' Toxic Soup Is: California's Wine Growing Regions

Pesticide Research Institute, a Berkeley company founded by PANNA database creator and pesticide expert Dr. Susan Kegley, has launched a detailed map showing the townships where neonicotinoids, the pesticides linked to bee colony collapse, are located.

The map was developed for beekeepers and is part of the company's Bee Resource Center.

Red areas are for the 95th percentile; orange for 75-95% percentile

The map is similar to the State Dept. of Public Health's Agricultural Pesticide Mapping Tool (from the Environmental Health Investigations Branch) but the Pesticide Research map is visually clearer and goes to the level of the neonicotinoids (which are not presented on the state tool as a default). Both tools have 2010 data (since the state department of pesticides is changing to a new computer system and has not released stats for 2011-12 - they should be available in June).

While the worst concentrations of neonicotinoids are found in the Central (San Joaquin) Valley and Salinas Valley (see the top 5% of usage in red squares on this map), our North Bay wine country is still alarmingly high.

The orange areas above show sites in the top quarter of the state from the 75th to 95th percentiles.

As you can see, a wide swath around Healdsburg and a township centered in Napa on the Rutherford-Oakville-Yountville AVAs are in this top 25% of users statewide.

In Sonoma, the state Dept. of Pesticide Research data for 2010 shows 2,362 pounds of imidacloprid (a neonicotinoid) spread at 424 sites over 8,166 acres.

In Napa, 796 pounds of imidacloprid were spread over 199 sites and 2,405 acres. From the map below, one can see that the area of highest concentration is over the AVAs of Rutherford, Oakville and Yountville.

Beekeepers and environmental groups recently sued the EPA over the use of other neonicotinoids linked to bee colony collapse. The EPA has said it will take 5 years to study the matter.

Neonicotinoids are used on more than wine grapes but wine grapes are among the top five crops in California where they are used.

FOr further reading, consult the Wines & Vines article, Wine Grape Pesticide Facing Greater Scrutiny