Mosquito larvicide studies with mom 585, a juvenile hormone mimic

Technical MON 585 contains only carbon, hydrogen and oxygen, and has the chemical structure of 2,6-di-t-butyl-4-(a,a-dimethylbenzyl) phenol. Data from the manufacturer show that the compound has an acute oral LD-50 of 1,890 mg./kg. to female rats. Technical MON 585 was dissolved in 95 percent ethanol and serially diluted so that the addition of 1 ml. of solution to 250 ml. H20 effected the desired test concentration. A 3 lb. MON 585/gal. emulsifiable concentrate (e.c), used in certain tests, was diluted with H20 and pipetted into the medium. Laboratory and simulated filed studies show that MON 585, a synthetic juvenile hormone mimic, was effective against larvae of Ae. aegypti, C. p. quinquefasciatus, C. tarsalis, Ae. taenirohynchus, A. albimanus and A. stephensi. Activity of the compound is expressed in death of newly formed pupae. Exposure of third instars to relatively high concentrations for intervals of 6 hours or less similarly resulted in mortality at the larval-pupal moult. The compound did not cause any larval mortality.