Sublethal effects of herbal insecticides, Azadirachtin and Palizin, on the life history, survival rate and life expectency of Trialeurodes vaporariorum (Hemiptera:Aleyrodidae)
Paper ID : 1915-24IPPC (R3)
Authors
1Plant Protection, Agriculture, Urmia, Urmia, Iran
2Department of Plant Protection, Faculty of Agriculture, Urmia University, Urmia, Iran.
3Plant protection department, Agricultural and natural resources research center of west Azarbaijan.Areeo.Urmia.Iran
Abstract
The greenhouse whitefly, Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae), is known as an economically pest on different vegetables, greenhouse and ornamental host plants. Due to the polyvoltine, polyphagous and resistant to insecticides resulted in the reduction of the management efficiency. Usage of herbal and organic insecticides could be considered as a complementary method in integrated pest management of aforementioned pest. For this purpose, in this study, the sub-lethal effects (LC25) of two insecticides, Palizin and Azadirachtin, on the biological properties and life table parameters of T. vaporarium were evaluated at greenhouse condition (25 ±2 ° C, R.H. 60 ±10 % and a photoperiod of 16 : 8 h (L:D). The dipping method was used in bioassay and life table studies. Briefly, the leaves of tomato were dipped into the related concentrations of insecticides for 30 s, then the same-aged (24h) adults of, T. vaporariorum were released on the treated leaves after 20 m.The biological and life table studies were done using 80 the same aged eggs as a cohort. The life history data of the greenhouse whitefly cohorts exposed to sublethal concentration of the aforementioned insecticides were analyzed using the computer program TWOSEX–MSChart based on the age-stage, two-sex life table theory. The results were showed that the used insecticides led to the prolonging of the preadult period compared to control (df=2,135; F=577.52; P=0.000). The survival rate of preadult stage was varied from 51% on control to 28% on Palizin. Additionally, the sublethal concentration of aforementioned insecticides resulted in significant decreasing of female (df=2,71; F=196.41; P=0.000) and male (df=2,61; F=183.14; P=0.000) longevity compared to control. The reproductive period and fecundity rate were affected by insecticides and the lowest reproductive period (2.73±0.60 days) and fecundity (8.64±2.67 eggs/life time) were obtained on Azadirachtin treatments. The life expectancy of the eggs was obtained 20.77, 18.57 and 13.97 days on control, Azadirachtin and Palizin treatments, respectively. Therefore, the findings of this research showed that either Azadirachtin or Palizin have negatively effects on the biological and life table parameters of the greenhouse whitefly which could be consider in management of T. vaporariorum.
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