California avocado farmers concerned about pest

LOS ANGELES — Avocado growers and scientists say a threat has emerged that could wipe out — or at least significantly damage — California's $300 million-a-year avocado industry.

The culprit is stenoma catenifer, better known as the avocado seed moth.

Native to South America, the moth — which burrows into the fruit to lay eggs and grow its larvae — is wreaking havoc on Peruvian avocado growers. And since the U.S. government began allowing imports of Peruvian avocados in January, growers fear it's just a matter of time before it arrives in the U.S. and begins destroying local crops.

"They don't have any idea of how to deal with it," said Mark Bruce, a Simi Valley avocado grower who is struggling to bring his 68-acre orchard into profitability after 11 years. "If it comes here, it could be the end of the avocado industry in California."

The U.S. Department of Agriculture maintains that existing safety guidelines will protect California's avocados from the Peruvian moth. Currently, all imported Peruvian avocados come from only certified pest-free areas and are inspected upon arrival.

But University of California, Riverside, entomologist Mark Hoddle, who is an expert on the pest, says it's almost inevitable the seed moth will one day make its way to the United States. Hoddle also agrees with growers that it could devastate state avocado crops.

Between February and April of this year, the U.S. has imported 120,000 pounds of avocados from Peru.

"It is a numbers game," said Hoddle, who is now in Peru studying the moth on a research project funded by the California Avocado Commission. "Large numbers of fruit moving into the same areas over long periods of time increase the chances that it will come in accidentally."

California grows 90 percent of the nation's avocados, which are harvested on 60,000 acres throughout San Diego, Riverside, Ventura and Santa Barbara counties and in the San Joaquin Valley.

Avocado pests can cost an individual grower hundreds of thousands of dollars each year. For example, the avocado thrip, common throughout the state, causes $4 million to $9 million in damage to the state's crop annually.

What worries Hoddle and the Avocado Commission is that his research so far in Peru shows that nearly 100 percent of the avocados grown in an interior area of Peru are infested with the seed moth. So far, though, he hasn't found the moth in existing certified export orchards, located in the coastal region of Peru.

Pesticides do not seem effective in managing the pest in Central and South America. In commercial orchards in Guatemala, despite heavy spraying, 45 percent of fruit was still infested, often containing multiple larvae. The moth has done similar damage to avocado crops in Brazil, infesting 60 percent of fruit treated with pesticides.