Thanks in part to financial support from the California Avocado Commission, a University of California-Riverside entomologist spent part of the summer in Peru studying the avocado seed moth, Stenoma catenifer.

The pest could pose a threat to California’s avocado industry if it makes its way northward.

Although the moth is native to a number of countries in South America, the region where it has been found in Peru — an isolated area in the Andes Mountains — is not an area where growers raise avocados for export, said entomologist Mark Hoddle.

Peruvian avocados that would be shipped to the U.S. are grown in export orchards certified by the U.S. Department of Agriculture in coastal desert areas hundreds of miles from the districts where the seed moth has been found, he said.

Hoddle, also a biocontrol specialist in the university’s department of entomology, and other researchers collected about 300 pest-infected avocados in Peru and are studying them and their natural enemies — known as biocontrol agents — in a laboratory.

Their goal is to identify natural enemies capable of controlling the moth before it arrives in California.

Hoddle described stenoma as a nocturnal moth that lays eggs on avocado branches and fruit. Caterpillars bore into fruit, doing extensive damage to pulp and the seeds, rendering it unmarketable.

“Infested fruit are easily identified by accumulations of insect frass at the exits of feeding tunnels on the surface of the fruit, and often white sugary residue drip from these openings,” he said.

Green twigs and woody branches with burrowing stenoma are brittle, snap easily and die from feeding damage.

It’s important to identify the pests and find a way to manage or combat them before they arrive in California, Hoddle said.

In the past, two of the major threats to California’s avocado crop — the persea mite and avocado thrips — were not known to scientists until they showed up in the state, and researchers had to scramble to come up with ways to control them, he said.

To monitor the pest in Peru, Hoddle set up pheromone traps in certified avocado export orchards as well as in non-certified avocado growing areas. The pest was not found in the certified areas, but males were trapped in some non-certified areas, as expected.

Researchers working with Hoddle already have set up a monitoring network to keep an eye out for the pest in California’s avocado-growing counties of San Diego, Riverside, Ventura and San Luis Obispo.

Hoddle partnered with Servicio Nacional de Sanidad Agraria, Peru’s equivalent of the U.S. Department of Agriculture’s Animal Plant Health Inspection Service, for his research in that country.

His next trip, set for mid-August, will be to India and Pakistan, where he will study the Asian citrus psyllid with the hope of developing a biocontrol project for that pest.

The psyllid, which already has had a devastating effect in Florida spreading a disease known as huanglongbing, was found in San Diego County in 2008 and poses a threat to California’s citrus industry if it begins to spread HLB.