Biochemical Studies of Na+,K+-ATP ase and Acetylcholinesterase Sensitivity to Phenothrin and Thiodicarb Among Different Egyptian Field Populations of Spodoptera littoralis

Seham M, Ismail

doi:10.21608/asejaiqjsae.2008.3179

Biochemical Studies of Na+,K+-ATP ase and Acetylcholinesterase Sensitivity to Phenothrin and Thiodicarb Among Different Egyptian Field Populations of Spodoptera littoralis

Document Type : Original Article

Author

Ismail Seham M

Center Laboratory of Pesticides, Sabahia, Alexandria, A.R.C.

10.21608/asejaiqjsae.2008.3179

Abstract

Enzymatic activity of Na +,K+ - ATPase and AChE of cotton leafworm Spodoptera littoralis collected from different four Egyptian field populations ranged from heavily- sprayed fields and cultivated fields were investigated and compared with a laboratory susceptible population. The highest levels of Na +,K+ - ATPase and AChE activities were found in Alexandria Governorate Egypt. The moderate leveals was found in El -Boheira Governorate, Egypt. Na + ,K+ - ATPase and AChE and were isolated from brain of S. littoralis larvae (4^th instar). The sensitivity of Na +,K+ - ATPase and AChE activity to Phenothrin and Thiodicarb respectively were measured by the I⁵⁰ values. The I⁵⁰values of Phenothrin on the Na +,K+ - ATPase activity were 0.01, 0.20, 0.36, 0.61 and 0.82μM for lab strain; Borg El- Arab; Abeis; Damanhour and Abou El- Matamir respectively. The I⁵⁰ of Thiodicarb on AChE activity were 0.22, 0.43, 0.54, 0.71 and 0.96μM for lab strain and four field strains respectively. The inhibition constant (Ki) values were determined for Na+,K+ - ATPase and AChE inhibitors. Values of Ki in the case of Phenothrin were 5, 18, 20, 30 and 45μM for lab strain; Borg El-Arab; Abeis; Damanhour and Abou El-Matamir respectively on Na+,K+ - ATPase activity. Similarly, Thiodicarb were 20, 28, 30, 40 and 50μM for lab strain and four field strains respectively on AChE activity. The results of the present study may add some forward steps to uses this enzymes indicate of effect this insecticides under study, in the IPM programs of the cotton leafworm.