Promising for conventional growers, too
But conventional growers have a broader range of tools to deal with codling moth. “If they’re going to use four different strategies, this can’t be expensive,” Landolt says. “It has to be mechanically applied and use a dirt-cheap material.”
He emphasizes that the foam won’t be a should add it to their arsenal as another way to reduce populations.
Initial tests in the lab and in research orchard blocks have focused on comparing foam and cardboard acceptability as a cocooning site, with suppression rate studies still to come.
Results so far are promising, Landolt says. More work is needed to refine the product. On the list for additional development is boosting the foam’s durability to better handle orchard conditions.
Direct blasts from under-tree sprinklers shorten the foam’s lifespan in its current formulation, he says. Without changes to the recipe, these increasingly popular sprinklers are likely to wash the water-based foam off trees before it’s done all it can against the larvae.
After application, the foam dries and forms a skin that most insects dislike, Glenn says. More field tests are needed to determine how the target larvae respond and find solutions.
High humidity also hastens the foam’s decomposition—the perfect trait for irrigated orchards in arid climates, such as Washington state and California, where humidity rises when the foam is no longer needed, Landolt says. But growers in other regions may need to time their applications more carefully.
Possible other uses
That’s a consideration when it comes to finding additional uses for the product. Lacey and Landolt see the foam potentially as a way to tackle similar pests in other tree fruit, such as citrus.
Lacey points to cherry bark tortrix, a pest common to western Washington, and apple clearwing moth, which has turned up in British Columbia and could migrate south to Washington, as examples where the foam might work.
In both cases larvae also burrow into tree bark. More pests and crops should help attract a commercial partner when the time comes to develop a marketable product, Landolt says.