Insecticidal Activities of Commercial Rosemary Oils (Rosmarinus officinalis.) Against Larvae ofPseudaletia unipuncta. andTrichoplusia ni. in Relation to Their Chemical Compositions

Abstract

Rosemary [Rosmarinus officinalis L. (Lamiaceae)] essential oil has insecticidal properties and is the active ingredient in a number of commercial insecticides. Like other plant essential oils, the chemical composition of rosemary oil can vary based on genotype, geography, climate, and method of preparation. This study explored the relationship between chemical composition and insecticidal activity of 10 commercial samples of rosemary oil, based on laboratory bioassays with two agricultural pests, the armyworm Pseudaletia unipuncta Haworth (Noctuidae) and the cabbage looper Trichoplusia ni Hübner (Noctuidae). Nine major terpenoid constituents of rosemary oil were quantified in the samples by gas chromatography-mass spectrometry (GC-MS). The major constituents were 1,8-cineole, α-pinene, β-pinene, and camphor; on average 1,8-cineole made up 52% of the oil by weight. Bioassayed individually, camphor was the most toxic compound to the armyworm (LD 50 =189.4 µg larva −1) whereas µ-terpineol was the most toxic to the looper (LD 50 =128.5 µg larva −1). LD 50 values for the ten rosemary oils ranged from 167.1 to 372.1 µg larva −1 in the armyworm and from 58.9 to 335.9 µg larva −1 in the looper. Correlation analysis comparing rosemary oil toxicity to chemical composition revealed slight but significant correlation for d-limonene and α-terpineol in bioassays with the looper but no correlations between constituents and toxicity with the armyworm. An "artificial" rosemary * Dedicated to Professor John Thor Arnason of the University of Ottawa, Department of Biology, on the occasion of his sixteith birthday.

Feeding and oviposition deterrent activities of microencapsulated cardamom oleoresin and eucalyptol against Cydia pomonella

“…In terms of the synergistic effects of the combination of terpineoids with 1,8-cineole, our findings are similar to those of Singh et al (2009). These additive and synergistic effects of binary mixtures against lepidopterans could be attributed to their ability to prevent habituation of the olfactory response in the larval and adult stages (Akhtar and Isman, 2003;Koul et al, 2003;Isman et al, 2008;Singh et al, 2009). For this reason, MEC-spice oleoresins composed of binary mixtures merit further study as potential deterrents or repellents for other lepidopteran pests.…”

“…Generally, the combined effect of binary mixtures of essential oil constituents was found to be greater than that of individual compounds owing to their additive and synergistic effects against lepidopterans (Isman et al, 2008;Singh et al, 2009). For example, the binary mixture of 1,8-cineole with α-terpinyl acetate in MEC-C formulation was more deterrent than MEC-E formulation containing 1,8-cineole alone against codling moth larvae and adults.…”

The influence of Rosemary plants (Rosmarinus officinalis) volatiles on Aphid (Myzus Persicae)

“…We hypothesized that the volatile compounds present in rosemary may have repellent effects to vegetable aphids. Some studies have shown that rosemary essential oil has insecticidal properties [13,14] . Isman et al [13] studied the insecticidal effects of rosemary oils on larvae of the moths Pseudaletia unipuncta and Trichoplusia ni in relation to the oils' chemical compositions.…”

“…Some studies have shown that rosemary essential oil has insecticidal properties [13,14] . Isman et al [13] studied the insecticidal effects of rosemary oils on larvae of the moths Pseudaletia unipuncta and Trichoplusia ni in relation to the oils' chemical compositions. Hori et al [14] found that rosemary oil as well as thyme oil strongly repelled the aphid Myzus persicae (Sulzer), and rosemary oil has been shown to repel other aphid species such as Aphis gossypii Glover, Macrosiphum euphorbiae [15] ,…”

Evaluation of Dietary Toxicity of some Essential Oil Allelochemicals for The Management of Chilo Partellus (Swinhoe)

“…1,8-cineole was the second best effective compound against C. partellus and this compound is shown to have potential against other lepidopterans like S. litura, Psedaletia unipuncta and Trichoplusia ni (Hummelbrunner and Isman 2001;Isman et al 2008). Linalool was significantly similar to thymol and 1,8-cineole in its activity against C. partellus and is known as a potent, efficacious compound against mosquitoes (Traboulsi et al 2002(Traboulsi et al , 2005Cheng et al 2009) and fruit flies ), however, moderate activity has been reported against red bud borer, Resseliella oculiperda (van Tol et al 2007).…”