Identification and field evaluation of the sex pheromone of a Brazilian population of Spodoptera cosmioides

Abstract

The objective of this work was to identify the sex pheromone of Spodoptera cosmioides and to evaluate whether there is pheromone cross‑attraction in Spodoptera sp. (Lepidoptera: Noctuidae). Spodoptera cosmioides gland extracts were analyzed by GC‑FID and GC‑MS. Wind tunnel and electrophysiology experiments were conducted to evaluate the role of gland compounds. In the field, different pheromone traps were tested: S. frugiperda commercial lure; (9Z)‑9‑tetradecenyl acetate (Z9‑14:OAc) and (9Z,12E)‑9,12‑tetradecadienyl acetate (Z9,E12‑14:OAc) trap; two females of S. cosmioides trap; and hexane control trap. Four acetates were identified in the S. cosmioides female gland extracts as Z9‑14:OAc, Z9,E12‑14:OAc, (11Z)‑11‑hexadecenyl acetate (Z11‑16:OAc) and hexadecyl acetate (16:OAc), but only the first two acetates induced electrophysiological responses from S. cosmioides male antennae. In wind tunnel experiments, S. cosmioides and S. frugiperda males responded more strongly to conspecific blends; however, there was some cross‑attraction, as 47% males of S. frugiperda and 25% males of S. cosmioides responded to heterospecific blends. In field experiments, S. frugiperda and S. cosmioides showed the same response pattern as observed in the wind tunnel bioassays. In summary, the sex pheromone components of S. cosmioides are Z9‑14:OAc and Z9,E12‑14OAc; they are important for conferring species specificity, and there is pheromone-mediated cross attraction between S. frugiperda and S. cosmioides.