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Research Notes J.Res. ANGRAU 41(2) 135-140, 2013 EFFECT OF SYNERGIST, TRIPHENYL PHOSPHATE ON RESISTANT GUNTUR STRAIN OF Spodoptera litura (fab.) IN COTTON I. ARUNA SRI and T. MADHUMATHI Department of Entomology, Agricultural College, Acharya N.G Ranga Agricultural University, Bapatla -522101 Date of Receipt : 12.01.2012 Date of Acceptance : 28.06.2013 Spodoptera litura (Fab.) is the first lepidopterous pest and second agricultural pest developed resistance in India. It has the ability to develop resistance to insecticides used for its control. Strains of S. litura resistant to cyclodienes, organophosphates and carbamates have been detected in all areas where intensive control operations were carried out with these insecticides. Synergists increase the lethality of insecticides by inhibiting insecticide detoxifying enzymes. This enables synergists to be used as tools for elucidating resistance mechanisms, especially if they are specific inhibitors of a particular resistance conferring mechanism such as detoxification of enzymes and also play a significant role in enhancing toxicity on the resistant strain to a greater extent (Kranthi, 2005). Mechanisms of insecticide resistance can be identified based on differential mortalities by combining various categories of synergists with insecticides (Prabhakar et al., 1988). The synergists act as useful indicators of metabolic mechanisms of resistance such as TPP for esterases (Casida, 1970). The synergist, Triphenyl phosphate (TPP) was tested with chlorpyriphos, quinalphos, endosulfan, cypermethrin and methomyl to know their synergistic effect. Synergists may also affect penetration of toxicants into insects. Hence, this study was taken. Experiments were carried out in the Department of Entomology, Agricultural College, Bapatla, Guntur district, Andhra Pradesh during two years viz., 2007-08 and 2008-09. The third instar larvae weighing 30 mg ± 0.011 S.E. of Guntur strain of S.litura was selected as the test insect in this study because it showed higher degree of resistance to the insecticides compared to Prakasam strain. Chlorpyriphos, quinalphos, endosulfan, cypermethrin and methomyl were the test insecticides and synergist used in the study was Triphenyl phosphate (TPP) for esterase activity. Bioassay was done by topical application method (FAO, 1971). Initially 2.0 per cent stock solution of the test insecticides and synergist, TPP was prepared from the technical grade by dissolving the required quantities after accurate weighment in acetone. The stock solution thus prepared was preserved in refrigerator for further use. Individual working concentrations for each of the test insecticides (chlorpyriphos, quinalphos, endosulfan, cypermethrin and methomyl) were prepared from the 2.0 per cent stock solution through serial dilution technique using acetone as solvent. Two microlitres of the respective test insecticidal solution was applied on the dorsum of second thoracic segment by micro applicator. Three replications were maintained for each insecticidal concentration with 10 larvae in each replication. Mortality of the larvae was recorded at 24, 48 and 72 hours after treatment (HAT). Further test insecticide in combination with TPP mixture in the ratio of 1:10 i.e., the concentration of synergist (TPP) was ten times more than that of the test insecticide was prepared and from that two microlitres was applied to the third instar S.litura larvae by topical application method. Three replications were maintained for each insecticidal concentration with 10 larvae in each replication. Mortality of the larvae was recorded at 24, 48 and 72 hours after treatment (HAT). The experiments were repeated so as to get mortality in the range of 5 – 90 per cent and the data were subjected to probit analysis (Finney, 1971) using MLP 3.08 software (Ross, 1987) and the respective LD 50, LD 90 and other parameters were calculated. The log dose probit (ldp) lines were drawn by plotting log dose (x) on x-axis and probits of respective doses on y- axis (Finney, 1971). email: issaiaruna@gmail.com 135
ARUNA SRI and MADHUMATHI Assessment of Synergistic Effect The Synergistic factor (SF) was calculated by dividing the LD 50 and LD 90 value of the individual test insecticide with the corresponding LD 50 and LD 90 value of the test insecticide + synergist mixture at 72 HAT. Synergistic ratio = LD 50 of the insecticide alone If the synergistic ratio is Chlorpyriphos + TPP LD 50 of the (insecticide + synergists) 1 – Synergistic effect =1 – Additive effect During 2007-08, the LD 50 and LD 90 values of chlorpyriphos in combination with TPP to the third instar larvae of Guntur strain of S. litura were 0.3336 and 2.5708; 0.1836 and 1.3946; 0.1643 and 0.9616 µg / larva at 24, 48 and 72 HAT, respectively. The Guntur strain of S. litura recorded the LD 50 and LD 90 values of 0.3040 and 1.9340 µg / larva for chlorpyriphos alone at 72 HAT The synergistic factor due to TPP at LD 50 and LD 90 levels was 1.85 and 2.01, respectively at 72HAT during 2007-08 (Table 1&3). During 2008-09, the LD 50 and LD 90 values of chlorpyriphos were 0.2026 and 2.3066; 0.1708 and 1.8280; 0.1596 and 0.6638 µg / larva at 24, 48 and 72 HAT, respectively. The Guntur strain of S. litura recorded the LD 50 and LD 90 values of 0.2620 and 1.2000 µg / larva for chlorpyriphos alone at 72 HAT . The synergistic factor at 72 HAT due to TPP at LD 50 and LD 90 levels were 1.64 and 1.81, respectively during 2008-09 (Table 2&3). Quinalphos + TPP During 2007-08, the LD 50 and LD 90 values of quinalphos in combination with TPP to the third instar larvae of Guntur strain of S. litura were 0.4186 and 3.1906; 0.2414 and 2.9340; 0.1720 and 0.9379 µg / larva at 24, 48 and 72 HAT, respectively. The Guntur strain of S. litura recorded the LD 50 and LD 90 values of 0.3600 and 2.2160 µg / larva for quinalphos alone at 72 HAT. The synergistic factor at 72 HAT due to TPP at LD 50 and LD 90 levels was 2.09 and 2.36, respectively during 2007-08 (Table 1&3). During 2008-09, the LD 50 and LD 90 values of quinalphos were 0.3304 and 4.9804; 0.1888 and 2.4928; 0.1588 and 0.7571 µg / larva at 24, 48 and 72 HAT, respectively. The Guntur strain of S. litura recorded the LD 50 and LD 90 values of 0.3500 and 1.7100 µg / larva for quinalphos alone at 72 HAT. The synergistic factor at 72 HAT due to TPP at LD 50 and LD 90 levels was 2.20 and 2.26, respectively during 2008-09 (Table 2&3). Endosulfan + TPP During 2007-08, the LD 50 and LD 90 values of endosulfan in combination with TPP to the third instar larvae of Guntur strain of S. litura were 2.2266 and 27.6715; 1.9179 and 8.7985; 1.7190 and 3.0661 µg / larva at 24, 48 and 72 HAT, respectively. The Guntur strain of S. litura recorded the LD 50 and LD 90 values of 2.0425 and 3.3052 µg / larva for endosulfan alone at 72 HAT. The synergistic factor at 72 HAT due to TPP at LD 50 and LD 90 levels was 1.18 and 1.07, respectively during 2007-08 (Table 1&3). During 2008-09, the LD 50 and LD 90 values of endosulfan were 1.2456 and 3.3512; 1.0960 and 3.0789; 0.6985 and 1.1452 µg / larva at 24, 48 and 72 HAT, respectively. The Guntur strain of S. litura recorded the LD 50 and LD 90 values of 1.7072 and 3.2882 µg / larva for endosulfan alone at 72 HAT. The synergistic factor at 72 HAT due to TPP at LD 50 and LD 90 levels was 1.90 and 2.19, respectively during 2008-09 (Table 2&3). Cypermethrin + TPP During 2007-08, the LD 50 and LD 90 values of cypermethrin in combination with TPP to the third instar larvae of Guntur strain of S. litura were 0.3550 and 2.0685; 0.2208 and 1.9155; 0.2099 and 1.5215 µg / larva at 24, 48 and 72 HAT, respectively. The Guntur strain of S. litura recorded the LD 50 and LD 90 values of 0.4700 and 3.1680 µg / larva for cypermethrin alone at 72 HAT. The synergistic factor at 72 HAT due to TPP at LD 50 and LD 90 levels was 2.24 and 2.08, respectively during 2007-08 (Table 1&3). 136
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CONTENTS PART I : PLANT SCIENCE Ads
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J.Res. ANGRAU 41(2) 1-10, 2013 ADSO
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ADSORPTION DESORPTION OF PENDIMETHA
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J.Res. ANGRAU 41(2) 11-15, 2013 STU
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STUDIES ON THE EFFECT OF PLANT GROW
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STUDIES ON THE EFFECT OF PLANT GROW
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PERFORMANCE OF DRUM SEEDER IN DIREC
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PERFORMANCE OF DRUM SEEDER IN DIREC
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J.Res. ANGRAU 41(2) 21-25, 2013 EFF
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EFFECT OF GRADED LEVELS AND TIME OF
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EFFECT OF GRADED LEVELS AND TIME OF
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ASSESSMENT OF GENETIC DIVERSITY IN
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J.Res. ANGRAU 41(2) 33-41, 2013 EST
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ESTIMATION OF HETEROSIS FOR YIELD A
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INTEGRATED EFFECT OF ORGANIC MANURE
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INTEGRATED EFFECT OF ORGANIC MANURE
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SCREENING OF LOCAL RHIZOBIAL ISOLAT
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CHARACTERIZATION AND CLASSIFICATION
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J.Res. ANGRAU 41(2) 59-67, 2013 IDE
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IDENTIFICATION OF SUPERIOR PARENTS
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EFFECT OF FRONT LINE DEMONSTRATIONS
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EFFECT OF FEEDING COMPLETE FEED CON
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EFFECT OF FEEDING COMPLETE FEED CON
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EFFICACY OF CONTROLLED INTERNAL DRU
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Page 88 and 89: EFFICACY OF CONTROLLED INTERNAL DRU
Page 90 and 91: EFFECT OF NSP ENZYMES AND PREBIOTIC
Page 100 and 101: HAEMATOLOGICAL AND BIOCHEMICAL PROF
Page 102 and 103: HAEMATOLOGICAL AND BIOCHEMICAL PROF
Page 104 and 105: INDIAN BREAD MAKING TOOLS - CONSUME
Page 110 and 111: Research Notes J.Res. ANGRAU 41(2)
Page 112 and 113: CROP COEFFICIENTS FOR DRIP AND CHEC
Page 116 and 117: STUDY ON THE EFFECT OF IRRADIATION
Page 120 and 121: EVALUATION OF DEFOLIANTS ON MUNGBEA
Page 122 and 123: YIELD, NUTRIENT UPTAKE AND ECONOMIC
Page 124 and 125: YIELD, NUTRIENT UPTAKE AND ECONOMIC
Page 128 and 129: NANO FOOD COLOURS FOR PRODUCT FORMU
Page 130 and 131: EFFECT OF ORGANIC FERTILISERS ON GR
Page 132 and 133: EFFECT OF ORGANIC FERTILISERS ON GR
Page 136 and 137: NUTRIENT UPTAKE OF MICROSPRINKLER I
Page 140 and 141: EFFECT OF SYNERGIST, TRIPHENYL PHOS
Page 142 and 143: EFFECT OF SYNERGIST, TRIPHENYL PHOS
Page 146 and 147: EFFECT OF HARVESTING STAGES AND DRY
Page 148 and 149: RESPONSE OF AEROBIC RICE TO IRRIGAT
Page 150 and 151: RESPONSE OF AEROBIC RICE TO IRRIGAT
Page 154 and 155: DRIP IRRIGATION SCHEDULE FOR CASTOR
Page 158 and 159: CHARACTER ASSOCIATION AND PATH COEF
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Page 162 and 163: Statement about ownership and other
Page 164 and 165: GUIDELINES FOR THE PREPARATION OF M
Page 166: ESSENTIAL REQUIREMENTS FOR CONSIDER
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