Agriculture Reference
In-Depth Information
Mating disruption will fail if growers or PCAs do not have a graduate-
level understanding of insect population behavior, and the potential and
limitations of monitoring data. Presence/absence monitoring will not
work. Applying the materials and assuming they work risks the crop.
Failing to verify the performance of the monitoring traps has resulted in
the loss of tens of thousands of dollars of fruit. Monitoring codling moth
mating requires an attentive scientific support network.
Several growers who have used pheromones methodically over multi-
ple years report their codling moth populations have declined to the
point where they are rarely detected. The extra expense of the codling
moth pheromone products is offset by the biological control of other
pests which formerly had needed additional pesticides because the
organophosphate used on codling moth disrupted natural enemies. The
Pear Pest Management Alliance funded additional work on biocontrol
opportunities that presented themselves in an organophosphate-free
orchard. Hemly and others hoped that pheromone products would elim-
inate the need for organophosphates, but he still finds that every few
years they have to apply one at the first hatch to keep the populations
low enough to allow the mating disruption to work.
The geography of California pear production played a facilitating role
in the success of the Randall Island Project, and subsequent pear partner-
ships. Pears thrive in the moist soils of the Sacramento River Delta, and
the narrow strip of orchard paralleling the river is the largest all-Bartlett
growing region in the world. It currently produces about half of the
state's pears. This is the southernmost and hottest pear district in the
United States, and growers here had to manage an extra generation
of codling moth most years. Thus, pear growers historically used
azinphosmethyl in large quantities in this district, attracting Clancy
Davis's attention. The geography of the pear commodity chain favored
partnerships formation to increase the adoption of pheromone mating
disruption (figure 6.2). California's other pear districts are concentrated
along alluvial strips in Mendocino and Lake Counties, although a few
Sierra Foothills orchards remain in production.
Other pear districts began clamoring for help funding pheromones
about the time Jean-Marie Peltier moved to the Department of Pesticide
Regulation and started the PMA program, which funded the California
Pear Advisory Board in its first round. In 1995, the Environmental
