Western Farm Press
To combat one of its major insect pests, the pistachio industry would like to take a page from the playbook of cotton growers and their highly successful pink bollworm (PBW) eradication program.
The nut growers’ target – it also plagues walnuts and almonds – is the Navel orangeworm (NOW), a vector for aflatoxin that is under increased scrutiny from pistachio processors.
The objective of a NOW control pilot project would be to do what the pink bollworm program has done, rearing and sterilization of massive numbers of moths per day. The project is in “the very preliminary stage,” said Bob Klein, manager of the California Pistachio Research Board.
The PBW program has been a resounding success; there have been no native pink bollworm detections since Spring 2012.
Klein said there is disagreement among researchers as to whether sterile NOW moths could be produced and in high numbers as is done with the PBW. Their physiology is, of course, different.
But if the objective is reached, the payoffs could be considerable. It would mean fewer costly sprays, higher survivability for beneficial insects, and a chance to come to grips with aflatoxin.
The California and Arizona cotton industries have used PBW eradication program for years. Sterile PBW moths are raised in a rearing facility in Phoenix, Ariz., and shipped to cotton producing areas in the United States. They are dispersed from airplanes.
The basic strategy is to flood the population of native PBW moths with sterile PBW moths at the ratio of 25 to one. The likelihood of two fertile PBW moths mating then becomes very small.
Sterile releases for NOW will start in this spring.
The strategy, proponents say, is “to suppress sterile moth mating of each generation so after a number of years, fertile NOW moths numbers are very minor or even cease to exist, as with PBW.”
The PBW program has been so successful that the Phoenix facility is no longer needed, except to sustain a very small population of PBW in case eradication becomes necessary again in the future.
If the NOW effort works, the plan would house production of sterile NOW moths in part of the Phoenix facility that would be shared with production of sterile PBW moths.
It would likely save some jobs at the facility, Klein said.
Some scientists believe NOW can successfully be reared in massive numbers, sterilized, and distributed by air in the same way the PBW moths are.
Jeff Gibbons, plant and grower relations manager with Setton Pistachio in Terra Bella, is among those on a pistachio industry task force who is a firm believer in the project’s chances for success.
Gibbons said a pioneer in the PBW effort 30 years ago met with the same sort of resistance by some scientists that is facing those looking at the NOW plan.