Pyridalyl insecticidal activity against

The discovery of a new insecticide begins with the generation of suitable lead compounds. They would be structurally modified to other compounds with higher insecticidal activity against target insects. Although various approaches may be used to create appropriate lead compounds, we should note that existing compounds were used as a lead compound in the case of pyridalyl. 

In contrast to such strong insecticidal activity against lepidopterous insects, pyridalyl showed little insecticidal activity against species of Hemiptera, Coleop-tera and Orthoptera. Such selectivity of the compound is reasonably regarded as a preferable characteristic for uses in I PM programs, because some natural enemy insects are included in those families. In fact, pyridalyl showed minimal impacts on various beneficial arthropods such as parasitic wasps, predatory insects and mite and pollinators (Table 30.3.5) [1, 6, 7]. 

Pyridalyl Discovery, Insecticidal Activity, and Mode of Action 11115 Table 30.3.3 Insecticidal activity of pyridalyl against lepidopterous pests. 

Table 30.3.4 Insecticidal activity of pyridalyl against insecticide resistant strain of P. xylostella.

Table 5. Insecticidal Activity of Pyridalyl against Lepidopterous Pests...

Pyridalyl resulted from a major synthetic program based on a series of lead conq)ounds and has proven to be very active against the larvae of some inq>ortant pests of cotton and vegetable crops. Pyridalyl also controls insecticide-resistant strains of lepidopterous pests as well as susceptible strains. It produces unique insecticidal symptoms so t it may have a different mode of action from any other existing insecticides. Pyridalyl is safer to mammals and various beneficial arthropods so that it Avill provide an mq)ortant tool in IPM and insecticide resistant management programs. Pyridalyl will become a safer chemical, and certainly contribute to establishment of sustainable chemistry. 

Pyridalyl is the only member of this class. It is a highly active insecticide against lepi-dopterous pests in cotton and vegetables. Its oral LD50 in rats is >5000 mg/kg. 

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