Japanese Beetles: Phenethyl Esters as Attractants13

Abstract

Phenethyl esters of C1–C6 carboxylic acids, all combined 7:3 with eugenol, were tested in traps for attractancy to Popillia japonica Newman in Clermont, Georgia, and Gibbsboro, New Jersey. The most attractive lures, phenethyl propionate and phenethyl acetate, were about equally attractive; their homologues, phenethyl butyrate, phenethyl valerate, phenethyl formate, and phenethyl hexanoate, were significantly less attractive. Among esters of the branched carboxylic acids, phenethyl isobutyrate was significantly less attractive than phenethyl butyrate. Many C5 and C6 acids caught more beetles than their straight-chain analogues, but the best of these compounds captured only about 25% as many beetles as phenethyl acetate or propionate.