Impact different levels of temperatures and relative humidity on toxicity of three pyrethroids insecticides against saw grain beetle

A. Alnajim, Ihab

	Impact different levels of temperatures and relative humidity on toxicity of three pyrethroids insecticides against saw grain beetle
Journal of Basrah Researches (Sciences)
Article 1, Volume 39, Issue 2, 2013, Pages 20-30 PDF (0 K)
Author
Ihab A. Alnajim
Abstract
The present study has been conducted to determine the effect of four temperatures 20, 25, 30 and 35 o C and two levels of humidity which were 55 and 75% on the toxicity of three pyrethroid insecticides cypermethrin 10 % EC , Alphcypermethrin 10 % EC and fenvalerate 20 % EC against saw grain beetle Oryzaephilus surinamensis ,the tested concentrations were 0.01 , 0.05 , 0.1 , 0.5 and 1ppm of insecticides. Results showed that each of the temperature and humidity has a significant impact on all tested chemicals, the high mortality percent were seen at temperature of 30 oC which were 80.10 , 76.13 and 60.67% for cypermethrin, Alphcypermethrin, fenvalerate respectively. While the level of humidity 55% has a significant effect on the mortality which were 60.72 and 52.90% for Alphcypermethrin and fenvalerate, respectively, and differs significantly than the level of humidity of 75%, while the level of humidity 75% has significant effect on the mortality for cypermethrin which was 73.27%.The results of toxicity showed the temperature 30oC has significant impact on LC50 which were 0.010 , 0.010 and 0.032ppm for cypermethrin, Alphcypermethrin and fenvalerate respectively, and the humidity 55% gave the lowest values for Alphcypermethrin and fenvalerate which were 0.033 and 0.084ppm respectively, while the LC50 of cypermethrin was the lowest at the humidity 75% which was 0.019ppm.
Keywords
Oryzaephilus surinamensis

Statistics Article View: 152 PDF Download: 132