Agriculture Reference
In-Depth Information
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Rachel's Dream: Agricultural Policy and
Science in the Public Interest
Optimizing Eco-Rational Technologies
Doug Hemly's great-grandfather planted pear trees on Randall Island,
about 15 miles south of Sacramento shortly after the California Gold
Rush, making this the longest continually cultivated perennial crop pro-
duction region in the state. The codling moth (
Cydia pomonella
) had
plagued the fruit grown by his great-grandfather, his grandfather, and his
father, so Doug had become accustomed to pesticides, although he had
never really liked using them. During the 1970s Hemly and his father
had actively cooperated with University of California (UC) researchers to
develop ecologically informed strategies for using pesticides, timing their
application carefully and using the least amount possible. This approach
controlled the pest populations, but relied to the greatest possible degree
on the beneficial action of predatory and parasitic insects. With the help
of UC scientists, Pat Weddle had developed protocols for carefully track-
ing the peaks and valleys of insect population dynamics following the
principles of Integrated Pest Management (IPM). Weddle, a professional
pest-control advisor, advised Hemly about pest management for years.
Their approach worked well until the bugs got uppity.
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Pesticide resistance develops within a population when repeated appli-
cations cull its most susceptible members, allowing only the fittest to
survive and reproduce. Synthetic pesticides intervene in the ebb and flow
of insect populations. This technology mimics the forces shaping natural
selection. The codling moth is a particularly robust pest, having demon-
strated resistance to lead arsenate in the 1920s and to DDT in the 1950s,
in the latter case after fewer than ten seasons. After World War II, the
chemical industries adapted organophosphates, originally designed as
