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Tea, Camellia sinensis (L.) O. Kuntze is a perennial and monoculture crop growing over extensive areas of Darjeeling hills, Terai and the Dooars regions. It provides an inexhaustible resource for colonization of the tea mosquito bug, Helopeltis theivora Waterhouse that cause substantial damage to the tea crop. Insecticides like organophosphates and pyrethroids are regularly applied to control this pest. Acetylcholinesterase (AChE) act by binding to the neurotransmitter (acetylcholine) in some synapses of the nervous system in many pests. The objective of this study was to investigate the quantitative and qualitative differences in the acetylcholinesterase in cerebral ganglion of this sucking bug, and then to compare between specimens that maintained in laboratory conditions and those collected from pesticide exposed tea plantations. A significantly high level of activity of the acetylcholinesterase was evident in the cerebral ganglia homogenate of the pesticide-exposed individual. Comparison of isozyme profiles also showed a common basic pattern with only one acetylcholinesterase band with Rm value of 0.13 that was observed both in pesticide exposed as well as laboratory maintained individual. The field-collected specimens showed deeply stained band indicating an intensive formation of AChE, which tells us much about the insecticide resistance level of this sucking pest. AChE based detection technique would be helpful for easy detection of the pesticide resistance status of this tea pest in near future.
Anonymous, Pests of tea in North-East India and their control, Tea Research Association. Tocklai Experimental Station, Jorhat, Assam, India, Memorandum. 1994;27:29-38.
O’Brien RD. Allelic genes in the house fly producing modified enzymes that cause organophosphorus resistance, Science. 1960; 132:298-299.
Oppenoorth FJ. Biochemistry and genetics of insecticide resistance, Comparative Insect Physiology, Biochemistry and Pharmacology. Kerkut GA, Gilbert LI. eds, Pergamon Press, Elmsford, Oxford. 1985;12:731-773.
Walsh SB, Dolden TA, Moores GD, Kristensen et al. Identification and characterization of mutations in housefly (Musca domestica) acetylcholinesterase involved in insecticide resistance”, Biochem. J. 2001;359(1):175-181.
Mutero A, Pralavorio M, Simeon V, Fournier D. Catalytic properties of cholinesterases: importance of tyrosine 109 in Drosophila protein”, Neuroreport. 1992;3(1):39-42..
Lewis PR, Shute CCD. The distribution of cholinesterase in cholinergic neurons demonostrated with the electron microscope, J. Cell. Sci. 1966;1:381-390.
Ellman GL, Courteny DK, Jr. Andres V, Featherstone MR. “A new and rapid colorimetric determination of aectylcholi- nesterase activity”, Biochem. Pharmacol. 1961;7:88-95.
Lowry OH, Rosebrough NJ, Farr AL, Randall R.J. Protein measurement with Folin phenol reagent”, J. Biol. Chem. 1951;193:265-275.
Aldridge WN, Reiner E. Enzyme inhibitors as substrates”, Frontiers of Biology, A. Neuberger and E.I. Tatum, eds, North Holland, Amsterdam. 1972;26:1-328.
Silver A. The biology of cholinesterase”, Frontiers of biology, A. Neuberger and E.I. Tatum, eds, North- Holland, Amsterdam. 1974;36:1-596.
Siegfried BD, Scott JG. Properties and inhibition of acetylcholinesterase in resistant and susceptible German cockroaches (Blattella germanica L.), Pestic. Biochem. Physiol. 2019;38:122-129.
Eto M. Organophosphorus pesticides organic and biological chemistry, CRC, Cleveland, OH; 1974.
Wang JJ, Cheng WX, Ding W, Zhi MZ. The effect of the insecticide dichlorvos on esterase activity extracted from psocids, Liposcelis bosrychophila and L. entomophila, J. Insect Sc. 2004;4:23-28.
Park NJ, Kamble ST. Decapitation impacting effect of topically applied chlorpyrifos on acetylcholinesterase and general eserases in susceptible and resistant German Cockroaches (Dictyoptera: Blattellidae)”, J. Econ. Entomol. 2001;94(2):499-505.