The concept and phenomenology of a new approach to the design of insecticides is described. The novel insecticides consist of modulators of the porphyrin-heme biosynthetic pathway, which, when used singly or in combination with δ-aminolevulinic acid, induce the massive accumulation of protoporphyrin IX in the treated insect. The uncontrolled protoporphyrin biosynthesis causes death of the treated insect in darkness and in light. In light, death appears to be photodynamic in nature. It is also shown that photodynamic damage can be induced by treating the insect with exogenous protoporphyrin or Mg-protoporphyrin. We propose the term "porphyric insecticides" to designate such insecticides. It is argued that the appeal of porphyric insecticides may reside (a) in the potential to design a large number of totally biodegradable formulations that can act as selective photodynamic insecticides and herbicides and (b) in the anticipated difficulty for insects to develop resistance toward such insecticides.
ASJC Scopus subject areas
- Agronomy and Crop Science
- Health, Toxicology and Mutagenesis