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Amini S, Nohooji MG, Khani M, Labbafi MR, Khalighi-Sigaroodi f. 2019. Biological activity of some essential oil constituents in four Nepeta L. species against Sitophilus oryzae L.. Biodiversitas 20: 338-343. Recently, there has been a growing interest in research concerning the possible use of plant extracts as alternatives to synthetic insecticides. Essential oils are among the best-known natural substances with insecticidal properties. These compounds may act as fumigants, contact insecticides, repellents, antifeedants and may affect growth and development of the insects. In an attempt to find a natural and inexpensive method for the control of stored-product pests, contact toxicity of essential oils of Nepeta cataria, Nepeta pogonosperma, Nepeta glomerulosa. and Nepeta binaloudensis. were investigated on adult insects of Sitophilus oryzae L. (Coleoptera, Curculionidae) in vitro condition. Chemical Composition, repellency and fumigant toxicity of the essential oils were investigated. Chemical composition of the essential oils of above plants were identified by GC-MS. 4aα,7α,7aβ-nepetalactone (82.74 %) was major component of N. cataria and also different isomers of nepetalactone were among the major compounds in N. Pogonosperma and N. binaloudensis oils. In fumigants bioassay, N. glomerulosa (124.318μL/L air) showed the highest toxicity against S. oryzae adults, followed by N.pogonosperma (150.49μL/L air) and N. cataria (152.630μL/L air), respectively. Also, the S. oryzae was repelled by N. cataria (91.61%) and N. binaloudensis (91.50 %), respectively.

Background: A significant amount of crop production is destroyed annually by pests in the storage and significant damage is caused to crops. Recently, the use of essential oils as an alternative to pesticides in pest control has been considered. Due to the presence of α-pinene, Cupressus genus is a significant source of plant insecticides that can act as fumigant, repellency and inhibitory insecticides. Objective: The aim of this study was to investigate the insecticidal properties, repellency and nutritional parameters of essential oils of Cupressus species on Sitophilus oryzae in 2018. Methods: The experiment was conducted in a factorial arrangement based on completely randomized design with 4 replications. The essential oils of the different species and populations of Cupressus were prepared by the Clevenger apparatus using a water distillation method. The major constituents in the essential oils were analyzed by GC-MS and the biological effects of the essential oils against adult S. oryzae were investigated. Results: In the analysis of chemical compounds, α-pinene was identified as the main essential oils of the above species. The result showed that among the species, C. arizonica showed the highest Fumigant toxicity to S. oryzae with LC50 = 172.30 μl/L air. In investigating the effect of repellency on S. oryzae, essential oils of C. sempervirens L. var. horizontalis (France) with 80.61 % showed the highest distance. Conclusion: Due to the toxicity and high repellency effect of Cupressus essential oils on S. oryzae, this genus has high potential for use in storage pest control.Coleoptera and they are storage pest, while feeding on storage materials and causes irreparable damage to crops [2]. In order to maintain the quantity and quality of stored cereals, it is necessary to reduce the population Essential oil bioactivity … MR. Labbafi, et al