The spinosyns are a new class of fermentation-derived insect control agents that are effective
against a variety of chewing insect pests. The successful introduction of spinosad into the agricultural
marketplace represents an important milestone in the use of natural products for commercial pest
control. The development of a natural product presents additional limitations relative to a synthetic
material. While the latter affords some degree of control in building appropriate physical attributes
such as photostability, a natural product, designed to function in a different environment, is often less
suited for traditional spray applications. Despite its intrinsic photolability, spinosad is stable enough to
perform under field conditions. In an effort to generate analogs with improved physical characteristics,
we have developed a variety of conditions for selectively modifying different portions of the
molecule, and we have discovered analogs with greater activity against a broader spectrum of pests.
The inability to translate improved greenhouse activity to actual ®eld conditions resulted in a detailed
study of the effects of formulations and crystallinity on biological activity. Through this effort,
measurably improved ®eld performance of synthetic spinosyn analogs relative to the natural product
have now been observed.
# 2001 Society of Chemical Industry