Insect hormones: olive oil is not an inert vehicle for hormone injection into locusts.

Like other fatty oils from plants, olive and peanut oils, the most commonly used vehicles for the injection of juvenile hormone and its analogs, contain substances that show effects similar to those of this hormone. A dose of olive oil smaller than that used to dissolve a single injection of juvenile hormone will cause nuclear enlargement in the cells of the prothoracic gland of the desert locus and advance the succeeding molt.