The effect of sublethal doses of Ethion and Imidacloprid on reproductive parameters of Cryptolaemus montrouzieri Mulsant (Col. ,Coccinellidae) in laboratory conditions

Subject Areas : entomology and othea arthropods

M. Keshtkar ¹ , Sh. Goldasteh ² , Z. Rafiei Karahroodi ³ , S. Chavoshi ⁴

1 - Department of Entomology, College of Agriculture, Islamic Azad University, Arak Branch, Iran
2 - Entomology Department, Faculty of Agriculture, Islamic Azad University, Arak Branch, Arak, Iran
3 - Entomology Department, Faculty of Agriculture, Islamic Azad University, Arak Branch, Arak, Iran
4 - Agronomy and Plant breeding Department, Faculty of Agriculture, Islamic Azad University, Arak, Iran

Received: 2010-06-29 Accepted : 2011-05-10 Published : 2012-05-21

Keywords:

Abstract :

The effect of sublethal doses of two pesticides, Ethion and Imidacloprid on reproductive parameters of Cryptolaemus montrouzieri Mulsant (Col., Coccinellidae) were investigated at constant laboratory condition. The insects were exposed to LC30 concentration of the pesticides during first 24 hours of their life. The amounts of LC30 and LC50 were respectively 244.58 and 385.13 for Ethion, and 130.83 and 221.45 ppm for Imidacloprid. The mean life span of adults in control was higher (41.2 days) than in treatments of Ethion (31.1 days) and Imidacloprid (26.7 days). The whole period of females' pre puberty in control and treatment with Ethion and Imidacloprid were record 30. 9, 33.9, 36.9 respectively. Sex ratio was calculated respectively 74.33, 54, and 46.67. Net fertility rate in control and treatment with Ethion and Imidacloprid were respectively record 449.48, 248.5, 182.45 eggs and net breeding rate were 394.6, 224.4, 166.7 eggs. The gross rates of hatching were calculated 0.87, 0.90 and 0.90 eggs. Mean egg per day in control and Ethion and Imidacloprid were 11.8, 9.6 and 9.5 eggs respectively. Intrinsic rate of natural increase (rm) in      control and treatments were 0.13, 0.10, 0.09 female/ female/ day respectively. These results       undicate that the sublethal doses of Ethion and Imidacloprid decrease the biological parameters of the coccineid.