Insecticidal Properties Of Essential Oils Research Articles

Comparative evaluation of antioxidant and insecticidal properties of essential oils from five Moroccan aromatic herbs.

This study describes the antioxidant and insecticidal activities of essential oils (EOs) of Mentha suaveolens subsp. timija, Thymus satureioides, Achillea ageratum, Cotula cinerea and Salvia officinalis widely used in Morocco as flavorings, food additives and preservatives. Sixty seven components were identified accounting for more than 95.0% of the total oils. M. suaveolens subsp. timija oil had as main components menthone and pulegone. A. ageratum oil was particularly rich in artemisyl acetate and yomogi alcohol. The essential oil of T. satureioides was characterized by high contents of carvacrol and borneol. C. cinerea oil contained trans-thujone and cis-verbenyl acetate as major constituents, whereas S. officinalis oil was characterized by trans-thujone and camphor. Antioxidant activities were examined by means of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), reducing power, β-carotene/linoleic acid bleaching and ABTS radical tests. In all assays, the highest antioxidant potency was observed in T. satureioides EO with IC50 values ranging from 0.15 ± 0.36μgmL(-1) to 0.23 ± 0.67μgmL(-1) across the four assays. The in vitro evaluation of the insecticidal activity showed that M. suaveolens subsp. timija EO present the highest insecticidal efficiency against adults of Tribolium castaneum with LD50 and LD90 values of 0.17 μL cm(-2) and 0.26 μL cm(-2), respectively and LT50, LT90 values ranged from 44.19h to 2.98h and 98.14h to 6.02h, respectively. Our data support the possible use of T. satureioides oil as potential antioxidant agent, while M. suaveolens subsp. timija oil can be developed as a new natural bio-insecticide.

Insecticidal Activity and Chemical Composition of Essential Oil from Artemisia Judaica L. Against Callosobruchus Maculatus (F.) (Coleoptera: Bruchidae)

The insecticidal properties of essential oil derived via the hydro-distillation method from aerial parts of Artemisia judaica L. were tested against the cowpea weevil, Callosobruchus maculatus (Fab.) (Coleoptera: Bruchidae). The repellent activity assay of essen- tial oil against C. maculates adults indicated that in concentrations of 63.7, 31.9, 15.9, 8.0 or 4.0 μg/cm2, the oil reduced egg laying by 92.5, 86.0, 61.8, 42.7 and 12.5%, respectively. Also, the residual-film assay showed that after 72 hours of treatment, concentrations of 50 and 40% were highly effective against the C. maculates adults. The sub-lethal effects of essential oil were investigated on fecundity and F 1 progany by exposing adult females to treated seeds. Both LC 25 and LC 50 of essential oil significantly reduced F 1 progany pro- duction compared to the control. The chemical composition of the essential oil was analyzed by GC-MS and the resulting oil piperi- tone (32.4%), camphor (20.6%) and (E)-ethyl cinnnamate (8.2%) were found to contain the major constituents of the oil. This provided the insecticidal properties of the essential oil against cowpea weevil.

Antifungal, phytotoxic and insecticidal properties of essential oil isolated from Turkish Origanum acutidens and its three components, carvacrol, thymol and p-cymene

The chemical composition of essential oil isolated by hydrodistillation from the aerial parts of Origanum acutidens was analyzed by GC–MS. Carvacrol (87.0%), p-cymene (2.0%), linalool acetate (1.7%), borneol (1.6%) and β-caryophyllene (1.3%) were found to be as main constituents. Antifungal, phytotoxic and insecticidal activities of the oil and its aromatic monoterpene constituents, carvacrol, p-cymene and thymol were also determined. The antifungal assays showed that O. acutidens oil, carvacrol and thymol completely inhibited mycelial growth of 17 phytopathogenic fungi and their antifungal effects were higher than commercial fungicide, benomyl. However, p-cymene possessed lower antifungal activity. The oil, carvacrol and thymol completely inhibited the seed germination and seedling growth of Amaranthus retroflexus, Chenopodium album and Rumex crispus and also showed a potent phytotoxic effect against these plants. However, p-cymene did not show any phytotoxic effect. Furthermore, O. acutidens oil showed 68.3% and 36.7% mortality against Sitophilus granarius and Tribolium confusum adults, respectively. The findings of the present study suggest that antifungal and herbicidal properties of the oil can be attributed to its major component, carvacrol, and these agents have a potential to be used as fungicide, herbicide as well as insecticide.

Insecticidal Activity of Essential Oils of Ceylon Cinnamomum and Cymbopogon species against Musca domestica

Insecticidal properties of essential oils of leaf and bark of Ceylon Cinnamomum zeylanicum Blume (Lauraceae), Cymbopogon nardus Rendle (Gramineae) and Cymbopogon citratus DC. (Gramineae) and their 10 compounds were investigated against Musca domestica (housefy). Cinnamomum zeylanicum bark and Cymbopogon citratus oils showed good knock down and mortality against M. domestica (LD50 1.37 and 1.71 μg/insect, respectively) than C. zeylanicum leaf (LD50 2.75 μg/insect) and C. nardus (LD50 3.10 μ/insect) oils. Cinnamaldehyde (65%) was a major constituent of C. zeylanicum bark oil, eugenol (77%) in the C. zeylanicum leaf oil, geraniol (24.8%) in the oil of C. nardus and citral (78.8%) in C. citratus leaf oil. Cinnamaldehyde, eugenol, eugenyl acetate, geraniol and geranyl acetate were more active against M. domestica than their corresponding essential oils, while cinnamyl acetate, citral, citronellal, citronellol and α-terpineol were less active.

Repellent and insecticidal properties of essential oils against housefly, Musca domestica L.

Plant essential oils possess diversified insecticidal properties. Under screening programme of survey of bioactive agents for insect control 31 essential oils from different botanicals (2% in acetone), were studied for repellency and direct toxicity (insecticidal) against laboratory bred houseflies, Musca domestica L. The essential oils obtained from Ocimum gratissimum L., Thymus serpyllum L., Illicium verum Hooks, f., Myristica fragrans Houtt., Curcuma amada Roxb. showed 100% repellent activity, and Acorus calamus L. and Thymus serpyllum L. showed about 40% insecticidal activity. Results were compared with N, N-diethyl-meta-toluamide, dimethyl phthalate, malathion, pyrethrum extract, thymol, mineral oil and piperonylbutoxide. Biochemical studies of these promising oils may emerge new leads in developing future pesticides.