Fumigant toxicity of Haplophyllum tuberculatum (Rutaceae) and Nepeta crispa (Lamiaceae) on the Indian meal moth

Abstract

The insecticidal activity of essential oil vapors of Haplophyllum tuberculatum (Sapindales: Rutaceae) and Nepeta crispa (Lamiales: Lamiaceae) were evaluated on third instar larvae of Plodia interpunctella (Lepidoptera: Pyralidae) as one of the major insect pests of stored products. Essential oils of the plants were obtained using Clevenger-type water distillation. GC-MS analyses of the oils demonstrated that the main compounds of H. tuberculatum were ρ-menth-2-en-1-ol-cis (20.15 %), ρ-menth-2-en-1-ol-trans (16.92 %), trans-Piperitol (13.23 %), Piperitone (7.34 %) and cis-Piperitol (6.72 %). It is an important plant that has many medicinal properties. 1,8- Cineole (32.98 %), s-Pinene (8.70 %), 4aa,7a,7aa-Nepetalactone (8.08 %) and 4as,7a,7as-Nepetalactone (6.1 %) were detected as the predominant component in N. crispa. The aerial parts of that are used in traditional medicine. The LC50 values were estimated after 24 hours for H. tuberculatum and N. crispa as 4.301 and 5.579 µl L-1 air, respectively. LC50 values were projected using probit analysis. Results on H. tuberculatum showed more toxicity against the Indian meal moth compared to the N. crispa. In conclusion, the essential oil of the two plants could have potential for application to stored grain and agricultural commodities to control of stored crop pests in IPM programs.