Sublethal effects of essential oils of peppermint (Mentha spicata L.) and coriander (Coriandrum sativum L.) on adults of Cotton Aphid, Aphis gossypii Glover, in laboratory conditions
عنوان دوره: دومین کنگره بین المللی حشره شناسی ایران
نویسندگان
چکیده
Aphis gossypii Glover is a serious pest of agricultural products. Essential oil as an alternative to chemical pesticides to control this pest is concerned. In this study, the insecticidal effect of essential oils of peppermint (Mentha spicata L.) and coriander (Coriandrum sativum L.) were studied on cotton aphid. The essential oils were prepared by hydro distillation method using a Clevenger-type apparatus and dehydrated using dry sodium sulfate and stored in glass containers with a volume of 5 ml with aluminum cover on the refrigerator at 4 °C. Bioassay carried out in temperature 27 ± 2 ° C, relative humidity 65 ± 5% with 16 hours of light and 8 hours of darkness. To determine LC50, five concentrations for peppermint 6.56, 10.36, 16.43, 26.03 and 41.28 and for coriander 16.39, 22.16, 29.90, 40.33 and 54.43 µl /liter of air along with control (distil water) and to determine LT50 by using LC50 concentration of essential oils at different times 2,7,12,18 and 24 hours by probit program was analyzed. Each concentration in three replicates on 60 adult insects with food material (leaves, cucumber) was used. Different concentrations of each essential oil on filter paper on the inside of the door glass with 305 ml capacity were poured. To study the sublethal effect essential oils, concentration of LC25 in completely randomized design experiment with three treatments (two main treatments and control with three replicates per treatment on 20 adults insect) analyzed by one way ANOVA and compared mean with tukey HSD (α= 0.05). LC50 and LT50 values of peppermin and coriander on adults of A. gossypii was 12.58 and 28.68 µl /liter of air and 9.96 and 12.69 hours, respectively. The net reproduction rate (R0) in treatments of peppermin and coriander were obtained 11.85 and 21.35 female/female/generate, respectively which showed a significant decrease in comparison with the control treatment (60.4). The intrinsic rate of population growth (rm) of both peppermin and coriander (0.28 and 0.30 female/female/day) and control (0.32) were not significantly different from each other. The finite rate (λ) of population growth in two essential oils and control were1.33, 1.36 and 1.38 days that showed no significant difference. Mean genitive time (T) for controls, peppermin and coriander were calculated as 12.54, 8.56 and 9.87 days, respectively. This essential oils can use as a safe pesticide for humans and the environment or as a template to build new pesticides for pest control in greenhouse.
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