http://eajbsf.journals.ekb.eg/ Toxicological and Biological Studies on Using Lufenuron, Chlorpyrifos, Spinosad and Emamectin Benzoate Insecticides for Controlling Cotton Leafworm, Spodoptera littoralis (Boisd.

This study was carried out at Quesna district, Menoufia governorate during 2017 growing season under semi field conditions against 2 nd and 4 th instar larva of Spodoptera littoralis (Boisd.) to evaluate the efficiency of combining Beauveria bassiana with certain insecticides (emamectin benzoate, methomyl and Bacillus thuringiensis) in tomato field. In general, data revealed, clearly, that methomyl had the highest efficacy against 2nd larval instar, where, the percentages corrected mortality were 98.28, 62.68 and 27.09% at concentrations RC,1/2RC and 1/4RC respectively. While, when 4 th larval instar treated by emamectin benzoate, the observed total percentage corrected mortality was the highest value (90.54%) at RC followed by methomyl (85.79%) at RC, whereas, when treated 2 nd and 4 th larval instar with fungi had the lowest values of percentage corrected mortality at all concentrations compared with remaining treatments. When treated larvae with mixture of fungi (B. bassiana) and insecticides percentages mortalities of second and fourth larval instar of emamectin benzoate + B. bassiana and methomyl + B. bassiana had the highest values after 24hrs. then decreasing gradually, but the highest values of percentage mortality of second and fourth larval instar when mixtures of Bacillus thuringiensis + B. bassiana were after fifth days at concentrate of insecticide 1/2RC and after third day at concentrate of insecticide 1/4RC. So mixing increases the efficiency of their insecticides.

ield experiments were carried out in Etay Elbroud districts, El Behira governorate In summer plantation (mid July) sawing of maize plant throughout (2016/2017) seasons to study the efficacy of insect growth regulator (Nova) biopesticides (Absolute and Diple 2x) and chemical pesticides (Jito, Coragen and Contradio) aguinst Spodoptera littoralis and on some accompanied predators (family coccinilidae). The results indicated that the percentage initial effect of the tested compounds reduction of infestation for being (85.1, 77.2, 73.3, 52.7, 50.1 and 39.2%) in the first season (86.2, 73.7, 67.7, 60.00, 49.3 and 46.2%) in the second season for Jito, contrado, Nova, Coragen, Absolute and Diple 2x respectively. The general mean of residual effect for Jito compound caused the servent effect recorded 88.7 and 88.55% as reduction percentage in both seasons 2016 and 2017, respectively. biopesticides recorded the least effect on predators being 26.6, 26.8 and 23.7% in the first season and also in the second season recorded 35.5 and 33.3% for Nova, Absolute and Diple x2 respectively while, the chemical pesticides Jito caused the highest mortality against predators.