California farms are facing a surge of agricultural pests on some of the state’s most valuable crops due to climate change, according to researchers at the University of California (UC).
Researchers at UC Merced and UC Davis say populations of three major insect pests – codling moth, peach twig borer and oriental fruit moth – are projected to increase due primarily to warming temperatures.
The insects attack almonds, walnuts and peaches.
California grows 80 percent of the world’s almonds and 100 percent of the U.S. commercial supply. California also is number one nationally in peach and walnut production.
“These three pests are notorious for infesting most of the walnut, almond and peach orchards of California, causing extensive damages by reducing quality of fruits and nuts,” says study co-author Jhalendra Rijal, UC Cooperative Extension integrated pest management advisor and entomologist for Stanislaus, San Joaquin and Merced counties.
The majority of almonds, walnuts and peaches are grown in California’s Central Valley, which scientists have observed is already seeing a warming trend from climate change.
The University of California researchers say that based on their research, they expect the pest infestation to get worse as the warming effects of climate change increase, particularly in the Central Valley.
Climate change can lead to shifts in the timing of seasons, including warmer winters, earlier springs and hotter summers, and these conditions can disrupt the natural life cycles of pests, the researchers say in the new study, “Climate Change Impacts On Insect Pests For High Value Specialty Crops in California,” published in the journal Science Direct.
The important new research is being led by Prakash Jha, UC Agriculture and Natural Resources assistant project scientist based at UC Merced.
The study revealed that due to increases in temperature, these insects are expected to appear up to 28 days earlier in the spring, and the time between generations is expected to shorten by up to 19 days. The changes may be gradual, but the researchers say that up to a whopping half-generation of these pests could be added within the next 20 to 30 years.
The increase in these pest populations poses a serious threat for future pest management, which would subsequently affect the state’s economy and employment related to specialty crops, says the University of California’s Rijal.
Farmers, as well as processing and other businesses allied to almond, walnut and peach growing, need to pay close attention to this new development because it has the potential to cause major harm to three of the Golden State’s top specialty crops.
“The increase in these pest populations poses a serious threat for future pest management, which would subsequently affect the state’s economy and employment related to specialty crops,” says the University of California’s Rijal.
Fighting the Pests
Increased heat leads to the further development of these insects, according to the researchers. Very little research has been done on this historically, which is why the University of California project is so important. This is the first in a series of studies the research team will be doing.
In this regard, the first thing the researchers suggest farmers do is to become familiar with the issue because more information can help farms be more resilient. They suggest utilizing the CalAgroClimate database, which informs farmers on the progress of pests during the season. The researchers will be including their study in the database.
Another key finding of the new study is that these insects are arriving about a month earlier in the spring than expected. Therefore, the researchers suggest pest traps be set as early as February 7, as soon as pest activity begins.
In addition to setting the pest traps earlier, the University of California researchers say preventive measures like planting pest-resistant crops, sanitizing orchards during the winter, or harvesting early could also help fight back against pest infestations.
California almond, walnut and peach growers also should reach out to their local agricultural extension representatives if needed.
If not treated, the University of California researchers estimate up to half a generation of these insects could be produced in just the next two decades.
This is an issue we need to keep a close eye on.
My Job Depends on Ag Magazine columnist and contributing editor Victor Martino is an agrifood industry consultant, entrepreneur and writer. One of his passions and current projects is working with farmers who want to develop their own branded food products. You can contact him at: victormartino415@gmail.com.
