Rats have invaded almond orchards across the Central Valley.
The Almond Board of California revealed in a newsletter earlier this month that a major rat infestation has caused potentially hundreds of millions of dollars in damages over the past year.
The big picture: Almond growers in Merced, Fresno, Kings and Kern counties have reported a spike in rodent populations, the Almond Board of California said.
- The rats are using irrigation canals and other waterways as corridors to rapidly spread between orchards and diverse agricultural fields.
- The California Department of Food and Agriculture found in a report released in February that over 112,000 acres have been affected by the rat infestation. Damages are estimated to range from $109 million to potentially $310 million. Damages cover machine and equipment repair, tree replacement and yield loss.
- The report recorded up to 32 rats per night per inspection site across the Valley.
Zoom in: The Almond Board of California cited one grower in its report who had to replace an entire drip irrigation system that was damaged by rats. That ran up a $20,000 bill to replace.
- Another grower estimated crop loss at 50% even though he was exterminating between 50 to 100 rats every day.
What they’re saying: UC Davis professor Roger Baldwin is an expert on rodents and has been fielding calls from farmers on how to combat the infestation, according to a report from Gannett.
- “There are inquiries and questions about doing interviews on rat control and giving seminars on rat control, and can I write articles about this,” Baldwin told Gannett. “The problem went from very, very low to being the No. 1 issue I’ve dealt with in my 17 years with UC.”
Driving the news: While Baldwin and other experts have not found a single answer as to why almond orchards are now being overrun by rats, they have pointed to a few factors that they believe are contributing to the problem.
- California’s long-term drought left over half a million acres of farmland unplanted at the start of the decade, keeping farmers from using pest-control in their fields.
- Once the drought ended in the 2022-2023 winter season, the above average rainfall led to more vegetation growth and more food for wildlife.
- California has also restricted certain pesticides, limiting some options that growers previously had to fight rodent populations.
