Amid growing pest problems, the diamondback moth threatens top crops.

At the center of one of Boutonnet Farms’ fields in Castroville is a small plastic box filled with liquid. It’s a pest trap, laced with pheromones that lure in bugs coming to feast on the surrounding crops. During the winter, the fewer bugs there are – specifically the diamondback moth – the better. Their life cycles are disrupted by colder temperatures and rain, slowing population growth before a busy spring and summer harvest season.

But in warmer years, that’s not the case.

“When it comes to the brassica pests, diamondback definitely has been the biggest issue we’ve faced over the last four or five years, and it looks like this year could be one of the worst we’ve had,” says Ryan Kelly, general manager of Boutonnet Farms. “It’s still early to tell, but we definitely had a heavier start than the last two or three years.”

Across the region, more exotic pests and diseases have been encroaching on Monterey County farms, according to Norm Groot, executive director of the Monterey County Farm Bureau. The diamondback moth has become one of the worst offenders. The bug has a penchant for brassicas – a family of plants that includes broccoli, cauliflower, Brussels sprouts and cabbage, which make up a majority of the crops Boutonnet Farms grows.

The problem isn’t Boutonnet Farms’ alone. Monterey County is the leading producer of broccoli and cauliflower in the United States, producing 48 and 30 percent of the nation’s supply.

“Some of the pesticide tools that were working years ago are not having the same level of effect as they used to,” Monterey County Agricultural Commissioner Juan Hidalgo says. “So it becomes increasingly difficult to manage the problem.” 


The entire crop at Boutonnet Farms is grown conventionally, not organically. Still, Kelly says that with a mix of chemical and non-chemical treatments – such as bug vacuums and biological controls – the resistance pests eventually develop to pesticides means growers must spray in higher volumes when alternatives aren’t working.

In 2025, the U.S. Environmental Protection Agency approved Isocycloseram for use on the diamondback moth, and Salinas Valley growers want to see state agencies approve it.

“Forty-nine other states have tools that California does not have,” Groot says. “But California has not yet done so, and it does not appear that they are moving to do so. So we are now at a disadvantage.”