ATTRACTIVENESS STUDY OF FOUR COMPONENTS OF Spodoptera frugiperda SEX PHEROMONE

Abstract

The fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), is a pest that causes severe damage to agricultural production in various parts of the world, being considered a polyphagous and cosmopolitan pest. The use of pheromones in pest control has grown in recent years due to its high selectivity and low toxicity. Thus, this work aims ware to synthesize 4 compounds which belong of the S. frugiperda pheromonal blend, which were (Z)-7-dodecenyl acetate, (Z)-9-dodecenyl acetate, (Z)-9-tetradecenyl acetate and (Z)-11-hexadecenyl acetate and test them in the field against the commercially available pheromone in Brazil, the Bio Spodoptera (BioControle).The final products were prepared following a generic six-step reaction route, which included diol halogenation reactions, carbon-carbon coupling, stereoselective partial hydrogenation of alkynes, hydroxyl protection and deprotection, and alcohol acetylation. The compounds were characterized by NMR (H1and C13) and GC/MS. Two formulations were prepared with the synthesized compounds: the first (formulation 1) was composed of (Z)-7-dodecenyl, (Z)-9-tetradecenyl and (Z)-11-hexadecenyl acetates; and to the other (formulation 2), a fourth component, (Z)-9-dodecenyl acetate, was included. The formulated mixtures were incorporated in rubber septa by immersion for one hour. Four treatments (formulation 1, formulation 2, commercial pheromone and hexane as experimental control) were used for attractiveness evaluation, with six replications each, inserted in delta traps placed in corn crops for a period of 30 days. The synthesis of acetates showed good overall yields, proving to be efficient. 12% of the insects were captured with formulation 1, 38% with formulation 2 and 51% with commercial pheromone. There was no capture in traps containing septa incorporated with hexane. The average capture of S. frugiperda adult insects did not differ statistically among treatments by Tukey test at 5% probability.