Commentary: City residents and farmers should work together against moth

Issue Date: June 24, 2009

By Paul Underhill

Paul Underhill

Organic farmers spend lots of time walking their fields, looking for insects and diseases. We know there are some insects we don't need to worry about, while others potentially can threaten an entire crop. When we find the latter, we act quickly to eliminate them before their populations explode, using pest controls that are ecologically friendly and approved for use in organic farming.

The U.S. Department of Agriculture recently declared Yolo and Solano counties under quarantine after the discovery of two light brown apple moths in Davis. The apple moth is a non-native pest that infests native vegetation, ornamental plants and food crops.

Light brown apple moths caused serious damage to these organic berries grown in Santa Cruz County. Yolo County farmers say similar problems can be avoided there, through cooperation with a quarantine aimed at preventing the pests' spread.

Farmers in Yolo and Solano counties are the local group most impacted by the quarantine. The infestation is currently isolated to the city of Davis, and the moths probably were brought in on ornamental plants. It is critical to local farmers that the infestation not spread to the agricultural areas of our county. Why?

First, an extensive infestation will make it extremely difficult and expensive for growers to move much of our produce out of the county, and even harder to ship out of state. Large and small farmers alike will be affected.

For example, growers who take vegetables or fruit to farmers markets in the Sacramento area would be required to have USDA inspectors on site before harvesting many of their crops. Any crops found to be infested would not be allowed to leave the farm. Larger farms shipping crops out of state or out of the country would be subject to similar inspections and rules.

Second, if a larger infestation occurs, USDA would begin requiring growers to treat broad swaths of farmland with pesticides to control the moth. Organic farmers will use organically approved methods to do this, but we will be forced to spray much more extensively, and frequently, than we currently do.

This is why your local chapter of California Certified Organic Farmers is asking you to fully support the efforts of the Yolo County Agriculture Department to contain the light brown apple moth infestation in Davis and prevent its spread.

Yolo County Agricultural Commissioner Rick Landon already has agreed to use only organically approved pest control measures and he has no plans for aerial spraying within the city of Davis. One method he plans to use is pheromone traps and confusion lures (twist ties) to keep the moths from breeding. Pheromones are not pesticides, are naturally occurring and are used in extremely low doses.

The county also plans to use Bt, an organically approved, naturally occurring insecticide used by many organic farmers. Bt is toxic only to caterpillars and does not affect beneficial insects. It biodegrades quickly in the environment, and is considered by the Environmental Protection Agency to have extremely low risk to humans.

Organic farmers in Yolo County use pheromone sprays and twist ties to control pests in walnuts, apples, pears, peaches and other tree crops. We use Bt selectively to control caterpillars in tomatoes, broccoli, cauliflower, tree fruit and dozens of other crops on our farms—and thus, often right around our own homes. We believe the material is completely safe for humans when used appropriately.

To put it in perspective, these two methods are vastly safer than the majority of insect control products sold in your local garden supply store, any of which may already be used by your next-door neighbor without your consent.

There are many questions about the light brown apple moth that are still unresolved, but one fact is clear: The USDA and California Department of Food and Agriculture consider this non-native pest a threat, and they have no intention of allowing it to spread farther into the Central Valley.

The Davis infestation appears to be small, and we have a unique opportunity to control and, if possible, eradicate it using organically approved materials. We hope you will join us in supporting this effort.

(Paul Underhill owns Terra Firma Farm in Winters. He is the Yolo chapter board representative for California Certified Organic Farmers and a member of the Yolo County Farm Bureau board of directors. This commentary was originally published in the Davis Enterprise.)

Permission for use is granted, however, credit must be made to the California Farm Bureau Federation when reprinting this item. Top