COMPARATIVE TOXICOLOGICAL AND BIOCHEMICAL STUDIES OF SOME INSECTICIDES AND ENTOMOPATHOGENIC AGENTS ON THE PEACH FRUIT FLY, BACTROCERA ZONATA(SAUND.) (DIPTERA:TEPHRITIDAE)

Abstract

The present study was carried out to evaluate the efficiency of six toxicants from different groups against the prepupae of the peach fruit fly, Bactrocera zonata. 1. Effectiveness of six toxicants against prepupae, pupae and adults of the peach fruit fly, Bactrocera zonata: The toxicity of the organophosphorus insecticides; Malathion, Dimethoate, Actellic, the miscellaneous toxicant, Abamectin, the entomopathogenic fungi, Bio-power and the entomopathogenic Nematodes to the prepupae (full grown larvae) ,pupae and adults of the peach fruit fly, B. zonata was studied. 1.1. Effect of organophosphorus i nsecticides ( Actellic, Malathion and Dimethoate): Exposure of prepupae and pupae of the peach fruit fly, B. zonata to sandy soil treated with reasonable concentrations of Malathion, Dimethoate, and Actellic caused obvious mortality of the pupae. The two insecticides; Dimethoate and Actellic showed no effect against prepupae; whereas, Malathion showed slight effect against the prepupae at the concentrations of 5000 and 6000 ppm.The two toxicants; Malathion and Dimethoate had slight latent effect against the emerged adults; while Actellic showed no latent effect against the emerged adults. Generally, Actellic was more toxic against the adults of B. zonata than Malathion and Dimet hoate. 1.2. Effect of the Miscellaneous insecticide; Abamectin, entomopathogenic fungi and entomopathogenic Nematodes: The toxicity of the miscellaneous toxicant, Abamectin and the entomopathogenic agents; fungi, Bio-power, Beauvaria bassiana and Nematodes, Sternernema feltiae against prepupae, pupae and adults of the peach fruit fly, Bactrocera zonata was studied. Exposure of the prepupae and pupae of the peach fruit fly, B. zonata to sandy soil treated with reasonable concentrations of the miscellaneous toxicant, Abamectin was effective against the pupae and has no effect against the prepupae. Also, the toxicant had no latent effect on the adults emerged from treated prepupae. Data of the present study showed that the Bio-power was highly effective against the pupae and had no effect on the prepupae. Also, the toxicant had no latent effect against the emerged adults. Results showed that S. feltiae was effective against the pupae and had no effect on perpupae. S. feltiae had no latent effect on the emerged adults from treated perpupae of B. zonata. 2. Total toxicity of the six toxicants: The total toxicity of the different concentrations of each toxicant was determined on the basis of the dead individuals of three stages ; prepupae, pupae and adults. The total mortality rates were used in drawing the toxicity lines . the toxicants were evaluated according to the following basis: