Is the Moth Menace overstated?
Last week, during my research into this week's Light Brown Apple Moth story, a couple of sources spoke off the record about research that they intimated will prove that the LBAM risk is overstated. Today that research was released and its authors claim that LBAM is controlled by natural predators, a claim based on what the authors describe as a fact-finding tour to New Zealand. (New Zealand is also where the California Department of Food and Agriculture and the US Department of Ag are currently conducting trials on a new, longer lasting, pheromone spray.)
In a press release sent to the Guardian, Dr. Daniel Harder, botanist and Executive Director of the University of California at Santa Cruz Arboretum, and Jeff Rosendale, a Watsonville grower and horticulturalist, said that during a three-week, 3,000-kilometer fact-finding study in New Zealand, they earned that "80 to 90 percent of LBAM larvae are destroyed by natural predators and never mature."
The report's authors also said they also spoke with current research experts on LBAM in New Zealand’s government agricultural agency, HortResearch.
“The success of New Zealand agriculture and horticulture professionals in controlling LBAM and other leaf-roller pests using Integrated pest management techniques and few or no chemical applications is a model of best IPM practices that can be readily adopted in California to control LBAM," the report's authors stated .
They claim that LBAM is a “superficial feeder” that typically causes only cosmetic damage to the surface of leaves and fruit and rarely penetrates a host fruit. They also claim that in New Zealand, "beneficial insects are considered the first and best line of defense and that insect growth regulators, which are based on derivatives from natural sources, are the primary least-toxic control used in agriculture for controlling leaf roller moths. Growth regulators do not negatively affect beneficial insects to any significant degree. "
According to the report, New Zealand stopped using organophosphates in 2001, so data on LBAM in New Zealand prior to 2001 do not accurately reflect LBAM’s behavior in agricultural and natural environments with healthy populations of beneficial predators.
The reports also calls into question CDFA's pheromone aerial spray program with the finding that “pheromone controls applied by any means cannot be effectively used across large diverse areas with varying canopy heights, mixed species composition, and varying terrain areas. “
The authors also note that, “Until tests reportedly carried out under a U.S. government contract in 2008 in southern New Zealand forests, pheromones had never been aerially applied in New Zealand.”
Said Dr. James Carey, a professor of entomology at University of California at Davis, who I interviewed in December, when the Guardian broke the news about the plan to spray the Bay area "The current distribution of LBAM in California covering 10 counties with a combined area of over 7,000 square miles (the size of Connecticut) suggests that this pest is not a recent introduction but has been in the state for many years, perhaps as many as 30 to 50 or more years."
Carey also noted, "The history of eradication programs in which an exotic insect is as widespread as is this pest in California suggests that we have little if any chance of success."
digg •
del.icio.us •
sphere •
google
•
