Biochemical response of cowpea weevil (Callosobruchus maculatus) to some current insecticides in the store

Sanchooli, Masood (2015) Biochemical response of cowpea weevil (Callosobruchus maculatus) to some current insecticides in the store. Masters thesis, University of Zabol.

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The cowpea beetle, Callosobruchus maculatus (Fabricius) (Coleoptera: Bruchidae) is one of the most important storage pests of cowpea seeds (Vigna unguiculata). This pest infests in stored legumes, including cowpeas (black-eyed peas), dried peas, chickpeas and lentils. Resistance of this pest to some chemical insecticides and failure of management programs have been reported in some documents. A developed program for chemical control should involve a thorough comparison of several pesticide compounds. In this study we compared contact toxicity of some insecticides (Chloropyrifos, Malathion, Pirimiphos-methyl and Spinosad) against C. Maculatus. Insects were exposed to the insecticides for 24 h in laboratory condition (28±2 °C and Darkness). The toxicity of insecticides followed in the order: chloropyrifos > pirimiphos-methyl > Malathion > spinosad. The lethal concentrations at 50% (LC50) on C. maculatus were 21.571, 71.476, 42.409 and 223.734 ppm for Chloropyrifos, Malathion, Pirimiphos-methyl and Spinosad, respectively. Bioassay results showed that the Chloropyrifos is more effective than other insecticides and Spinosad had the lowest contact toxicity. The effect of the Sublethal dose (LC30) each of the aforementioned poisons on the activity of the detoxifier enzyme showed significant differences in the level of 5%.The relative activity of the carboxyl-esterase affect the sublet Hal in comparison with control activities were reported for any of the insecticides, Chloropyrifos, Malathion, Pirimiphos-methyl and Spinosad, the measured alpha-Naphtyl-acetate substrates croakiest river were 115,147, 132 and 102 percent and the measured beta- Naphtyl-acetate substrates croakiest river were, 107, 151, 121, 101 percent. Relative activity of the esters enzymes observed under the affection of LC30 Malation. In Native-Page enzymes, with the similar test, the results of measurement of esters and band Malation treatment showed that they were broader and color than the other bands. The impact of LC30 insecticides on the activity of acetyl cholinesterase (AChE) showed significant differences in the level of 5%. Relative activity of AChE and control for Chloropyrifos, Malathion, Pirimiphos-methyl and Spinosad, following LC30 were, 40, 87, 71 and 91 percent, respectively. According to the results, the highest inhibition of the AChE was observed by colorpayerifos and pirimiphos-methyl, respectively. According to the results of the experiment, cowpea beetle has high sensitive related to organ phosphorus insecticide. This issue, due to the low concentration of insecticides and esters enzymes activity, is evident.

Item Type: Thesis (Masters)
Uncontrolled Keywords: resistance, insecticide, electrophoresis, detoxification
Subjects: Q Science > QL Zoology
Depositing User: admin admin1 admin2
Date Deposited: 28 May 2016 06:26
Last Modified: 28 May 2016 06:26

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