Navel orangeworm is a significant threat to California’s pistachio and almond industry as hull split begins early for both tree nuts, which creates an entry for NOW larvae to bore into the hull and feed on the kernel.
Sanitation, the practice of removing unharvested “mummy” nuts from the orchard floor is considered the most critical step in managing navel orangeworm. Many growers also look to sterile insect release as part of broader biological control of the NOW, but those conventional sterilization techniques often come with some challenges.
The biosecurity platform Flyttr, has developed a new program that deploys the company’s biological engineered males to enhance the effectiveness NOW pest control. Conventional sterilization uses irradiation and that can often compromise stamina and flight performance. Flyttr says its “Friendly” genetics-based approach offers “competitive males that can effectively find and mate with wild females under real farm conditions.”
Flyttr’s “Friendly” genetically engineered, self-limiting males are fully fertile, but they pass on a self-limiting gene to their offspring. Female offspring inheriting the gene die before reaching adulthood. Male offspring inherit the gene, survive to adulthood, and continue to pass the gene on to future generations, which dramatically reduces wild pest population over time.
The program is supported by the Almond Board of California and the Foundation for Food & Agriculture Research.
Flyttr estimates NOW’s economic impact to growers to be roughly $800 million annually on roughly 1.5 million acres of almond and pistachio orchards.
The program will focus on developing an implementation-ready NOW product that growers will integrate into pest management strategies already in place. A Flyttr spokesperson told The Packer, “Sanitation remains one of the foundations of navel orangeworm management, and we do not see that changing.”
Well-executed sanitation can leave some surviving pest populations which become the source of the next generation of NOW in an orchard.
“The challenge is that achieving near-perfect sanitation across thousands of acres is increasingly difficult and expensive. Labor availability, labor costs, fuel costs, and the sheer scale of modern orchard operations can make it difficult to consistently reach the low mummy counts growers want,” the spokesperson says. “Rather than replacing sanitation, it will be designed to strengthen the overall program by suppressing the breeding population right from the start, then continuously throughout the season.”
Another challenge growers face is neighboring orchards with differing sanitation levels can also become a source of new populations into an otherwise “clean” orchard.
“That’s where more area-wide biological approaches will become important,” a Flyttr spokesperson told The Packer.
Flyttr says that reducing baseline moth populations will help lower overall pest pressure. It also has the potential to help growers reduce insecticides over time and “help preserve effectiveness of existing tools by reducing selection pressure for resistance,” the spokesperson says.
And combining biological controls with insecticides and orchard sanitation will provide a more holistic pest management strategy, Flyttr says.
“Lowering dependence on existing tools aligns with integrated management principles, with the aim of improving outcomes for growers and the environment,” the spokesperson says. “The combination of sanitation and biological suppression will address both sides of the problem: removing existing reservoirs while simultaneously shrinking the breeding population that would otherwise rebuild.”
