A new beetle for California growers to be aware of, Carpophilus truncatus, has been identified in both almond and pistachio orchards. Australia has been dealing with the pest in almonds for several years now. Associate Cooperative Extension specialist in the Department of Entomology at UC Riverside, Houston Wilson said Australians’ experience with the pest will be helpful in formulating management strategies in California. The pest has already been confirmed in several areas of the state.
“We have official identifications from Merced County, Madera County, and Kings County. We’re in the process of taking in samples from all the other counties in the San Joaquin Valley,” Wilson explained. “Currently we’re sorting through a lot of beetles to identify in the lab. We’ve been going through those and we should be able to produce a map hopefully in the next few weeks that shows the full extent of the infestation.”
Researchers are also in the process of developing guidance materials for California growers. Wilson said they will be doing focused outreach centered around monitoring and management strategies. The pest is problematic because the larvae bore into nuts, leaving distinct oblong-shaped holes and fine, powder-like frass. It is likely the pest has been in California for some time already and mistaken for other pests. Reports in other regions of the world indicate that the Carpophilus truncatus would also be problematic for walnut growers.
“There’s some dispute about some of the species delineations within this Carpophilus group. There was another species being reported on walnuts in Argentina. You then have the group in Australia reporting what they were calling a different species, just on almond. Then there’s reports out of Italy most recently of another Carpophilus beetle attacking walnuts,” Wilson explained. “Currently, it looks like that may all be the same species actually, this Carpophilus truncatus.”
Brian German
Ag News Director / AgNet West