Document Type : Original Article
Authors
1
Plant Protection Research Institute, ARC, Bacous, Sabahia, Alexandria Egypt.
2
Central Pesticides Laboratory, Sabahia Station.
3
Central Pesticides Laboratory, Sabahia Station
Abstract
Field evaluation of four conventional insecticides and one microbial insecticide against black cutworm (BCW), Agrotis ipsilon, at two locations in cotton during 2008 and 2009 seasons were carried out in this study. Susceptibility of the two field strains compared to the laboratory strain for the five insecticides also was studied in the laboratory. At Abou-Elmatameer location, triazophos and Bacillus thuringiensis var. kurstaki revealed the highest reduction percentages of BCW all over the experiment period during the two seasons. Triazophos caused BCW reduction percentages 91.7, 93.2. 94.1 and 94.5% during 2008 season, and 88.4, 90.6, 90.9 and 89.9% during 2009 season, after 3-, 6-, 9- and 12-days post-treatment, respectively. Bacillus thuringiensis kurstaki reduced BCW population by 68.2, 90.0, 92.7 & 93.2% at 2008 and 69.7, 87.3, 90.6 & 90.5% at 2009 after 3-, 6-, 9- and 12-days post-treatment, respectively. On the other hand, λ-cyhalothrin gave the least BCW control. At Abees location, B.t. kurstaki recorded the highest BCW reduction percentages in the two seasons. During 2008, B.t. kurstaki achieved 73.7, 87.1, 90.0 and 89.4% reduction in BCW population after 3-, 6-, 9- and 12-days post-treatment. These reduction percentages were 71.7, 90.5, 89.1 and 90.9% after 3-, 6-, 9- and 12-days post-treatment, respectively, at 2009. Reduction percentages of BCW achieved by carbosulfan, chlorpyrifos, triazophos and λ-cyhalothrin at 2008 and 2009 were comparable and significantly lower than B.t. kurstaki. Black cutworm reduction percentages achieved by carbosulfan, chlorpyrifos, triazophos and λ-cyhalothrin at Abou-El-Matameer were significantly higher than at Abees in the two seasons. On the other hand, at the two seasons, BCW reduction percentages caused by B.t. kurstaki were not significantly different at the two locations. At the laboratory, Abees strain exerts tolerance ratios higher than Abou-Elmatameer strain to the tested conventional insecticides. The two field strains had no tolerance to B.t. kurstaki compared to the laboratory strain. Therefore, B.t. kurstaki may be considered as a good alternative for controlling BCW.
Main Subjects
)
View on SCiNiTO