Repellent activity of Nepeta grandiflora and Nepeta clarkei (Lamiaceae) against the cereal aphid, Sitobion avenae (Homoptera: Aphididae)

Nepeta spp. (Lamiaceae) contain principally the nepetalactone isomers (4aS,7S,7aR) and (4aS,7S,7aS)-nepetalactone, but also a diverse range of other natural products. Analysis of Nepeta grandiflora and Nepeta clarkei revealed the presence of predominantly sesquiterpene compounds, and, for N. clarkei, the major component as geranyl acetate. Amongst the compounds identified in both oils was (S)-germacrene d, a previously reported potent arthropod repellent. Oils from both Nepeta spp. displayed strong repellent activity against the cereal aphid, Sitobion avenae.