Synergism among some insecticides and ergosterol biosynthesis inhibiting fungicides against pectinophora gossypiella (saund.) [electronic resource].

Includes reference.

The toxicity of organophosphorus insecticide chlorpyrifos, pyrethroid insectiCide cypermethrin, insect growth regulators, chlorfluazuron and biocide as a natural products spinosad increased when mixed with the ergosterol biosynthesis inhibiting (EBI) fungicides to newly hatched larvae of Pectinophora gossypie//a. This study was carried out by feeding newly hatched larvae on artificial diet treated with different concentrations of the tested compounds either alone or in mixtures with EBI fungicide or IGR. Interestingly, these fungicides did not kill the larvae up to 100 ppm, moreover 20 ppm of each EBI fungicide with concentrations of the insecticides increased the toxicity of these insecticides. Also, all data indicated that the calculated LCso of the insecticides alone were higher than the insecticides and fungicides or IGR. For instance, chlorpyrephos at 6.25 ppm caused 90.0 % larval mortality and 100.0 % larval mortality when mixed with 20 ppm of each fungicides or 3 ppm when mixed with IGR. The LCso of chlorpyrifos alone were higher than that of chlorpyrifos when mixed with EBI fungicides and chlorfluazuron as IGR. For example, chlorpyrifos had LCso equal 2.89 ppm, but 0.88, 0.48, 0.26, 0.26, and 0.13 ppm when mixed with difenoconazol, tetraconazol, imazalil, fenarimol and chlorfluazuron respectively.

Summary in Arabic.

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