الفهرس | Only 14 pages are availabe for public view |
Abstract SUMMARY Toxicological and biological impact of four insecticides from four different groups, i.e. fenvalerate (syntheticx pyrethroid), carbosulfan (carbamate), triazophos (organic phosphate) and Pyriproxy~en ~lnsect Growth Regulator) were evaluated on the” mole-cricket, !L.. africana, one of the most important pests on many crops. Results obtained may be summarized as follows: 1- ~ africana 4th instar n~fiph, in laboratory tests, waS more sensitive to carbosulfan than other tested compounds; the descending order of toxicity according to values of LC50’s was carbosulfan, triazophos, fenvalerate and Pyriproxyfen, although differences”~eremsignificart.The arrangement according to LegO was carbo5ulfanm fenvalerate, triazophos with marginal diflerences, while Pyriproxyfen was conspicuously less toxic, the change of arrangement of Xhe three conventional insecticides was mainly brought about by difference in slope of Ld-P lines. 2- S-71639 and Sumicidin caused reductions of weight of full-grown nymphs. 3- Pyr-iproxyfen showed a detrimental effect by increasing significantly pre-oviposition periods and reducing number of - ---”.-~~-~----”--~------ - 85 - nests and eggs/female. in a manner in comparable to any other toxicant tested. 4- Pyriproxyfen and fenvalerate had some latent effect on the sexual ratio of ~ africana adults. 5- Pyriproxyfen achieved the lowest percent of hatchability as it varied between 18.1 and 0.0 % according to concentration. Other tested compounds had slight effects on hatchability, 6- In field trials, triazophos. fenvalerate and carbosulfan were almost ’e~ui-toxic in poisonous baits for molecrickets while Pyriproxyfen was the least effective on molecrickets in cotton field in terms of rapid evaluation but. in view of laboratory results would show a great impact on the next generation. |