الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 194 |  |  |
| | | from | 194 | | |
Abstract
This study is an attempt to investigate the efficiency of emamectin benzoate and hexaflumuron on the eggs and the 1st instar larvae of Helicoverpa armigera (Hübner), under the laboratory conditionshexaflumuron was ineffective when eggs were treated by field rate compared to emamectin benzoate and alpha cypermethrin that induced 100% mortality only when the recommended field rate was applied. The LC50 values of emamectin benzoate, hexaflumuron and alpha cypermethrin on the 1st instar larvae were 0.004, 2.44 and 11.36 ppm, respectively based on formulated materials. The results showed that emamectin benzoate, hexaflumuron were more effective insecticides compared to alpha cypermethrin. The mean larval duration periods were 12.0, 13.7 and 5.0 days when treated with the LC25values of emamectin benzoate, hexaflumuron and alpha cypermethrin compared to 16.0 days recorded for control. It is obvious that the three tested insecticides induced highly significant increase in larval and pupal mortality. Emamectin benzoate and hexaflumuron showed severe reduction in adult fecundity, eggs fertility and hatchability. On the other hand, the LC50 of emamectin benzoate, hexaflumuron and alpha cypermethrin recorded0.044,46.70,and 11.98 in feeding toxicity and 0.006, 1.51 and 0.609 by contact toxicity, respectively. Emamectin benzoate proved to be the most potent insecticide, feeding and by contact to honeybee workers at LC50, whereas the hexaflumuron was the least toxic one. The repellent activity of the tested insecticides was higher during the first day of application, Emamectin benzoate proved to be the most potent in repelling bee forgers initially and during the 1st day (98.81%), meanwhile hexaflumuron was the least potent one, initially and in the two days, recording 91.68 %in the 1st day and 62.87 % in the second day. In addition, data revealed that hexaflumuron treatment was safety to chrysoperla.carnea eggs whereas;emamectin benzoate and alpha cypermethrin were highly toxic. Toxicity to C.carnae larvae at LC50 recorded 0.005, 10.15 and 2.67 ppm of emamectin benzoate, hexaflumuron and alpha cypermethrin, respectively.