Synthesis and biological activity of methyl 2,6,10-trimethyldodecanoate and methyl 2,6, 10-trimethyltridecanoate: Male produced sexual pheromones of stink bugs Euschistus heros and Piezodorus guildinii

Methyl 2,6,10-trimethyltridecanoate (1) and methyl 2,6,10-trimethyldodecano ate (2) have been identified as male-produced sex pheromones of the Brazili an soybean stink bugs Euschistus heros (F.) and Piezodorus guildinii (Westw ood). In order to establish a defined attractive blend for both species, co mpounds 1 and 2 were synthesized as mixtures of stereoisomers to be employe d in behavior bioassays. (+/-)-Citronellol (3) was utilized as starting mat erial. and the syntheses was carried out in six steps with good overall yie ld. When tested alone, synthetic compounds 1 and 2 proved to be active in a two-choice olfactometer: however, a 20:1 mixture of 1 and 2 was much more attractive to E. heros females. A similar blend had been found among the he adspace volatiles of males.