Synthesis and field bioassay of some analogs of sex pheromone of citrus mealybug, Planococcus citri (Risso)

A series of structural analogs of (s+)-cis-(1 R)-3-isopropenyl-2,2-dimethylcyclobutanemethanol acetate, sex pheromone of the citrus mealybug, Planococcus citri (Risso), was synthesized. The analogs were tested in a field bioassay in order to determine the structure-activity relationships of the pheromone. All changes in structure reduced the activity of the test compounds, to various degrees. The most active analog tested was the homolog (+)-cis-(1 R)-3-isopropenyl-2,2-dimethylcyclobutaneethanol acetate (IV), whose activity, at a higher dosage, was comparable to that of the pheromone. The alcohol (+)-cis-(1 R)-3-isopropenyl-2,2-dimethylcyclobutanemethanol was tested in mixtures with the pheromone and found to be neither an inhibitor nor a Synergist. The results show that all functional groups of the pheromone molecule are essential for optimal biological activity.