INDUCTION OF PHEROMONE PRODUCTION IN A MOTH BY TOPICAL APPLICATION OFA PSEUDOPEPTIDE MIMIC OF A PHEROMONOTROPIC NEUROPEPTIDE

An amphiphilic analog of Locusta myotropin II (Lom-MT-II), Glu-Gly-Asp -Phe-Thr-Pro-Arg-Leu-amide, was synthesized by addition of 6-phenylhex anoic acid (6-Pha) linked through alanine to the amino terminus, This pseudopeptide, [6-Pha-Ala(0)]Lom-MT-II, was found to have pheromonotro pic activity equivalent to pheromone biosynthesis activating neuropept ide when injected into females of Heliothis vivescens, Topical applica tion of [6-Pha-Ala(0)] Lom-MT-II or Helicoverpa tea-pheromone biosynth esis activating neuropeptide (PBAN), dissolved in dimethyl sulfoxide, to the descaled abdomen of females induced production of pheromone, al though more Hez-PBAN than [6-Pha-Ala(0)]Lom-MT-II was required to obta in significant production of pheromone, Application of [6-Pha-Ala(0)]L om-MT-II, dissolved in water, to the abdomen induced production of phe romone, but neither Hez-PBAN nor Lom-MT-II dissolved in water stimulat ed production of significant amounts of pheromone. Dose- and time-resp onse studies indicated that application of the amphiphilic mimetic in water induced pheromone production in as little as 15 min after applic ation and that the effects were maintained for prolonged periods, Thes e findings show that amphiphilic pseudopeptide mimics of insect neurop eptides will penetrate the insect cuticle when applied topically in wa ter and induce an endogenous response.