Author/Authors :
Arif, Muhammad Jalal University of Agriculture - Department of Entomology, Pakistan , Abbas, Qaisar University of Agriculture - Department of Entomology, Pakistan , Gogi, M. Dildar University of Agriculture - Department of Entomology, Pakistan , Ashfaq, Muhammad University of Agriculture - Department of Entomology, Pakistan , sayyad, Hussnain Ali Bahaudin Zakariya University - Institute of Biotechnology, Pakistan , Arshad, Muhammad University of Agriculture - Department of Entomology, Pakistan , Khan, Muhammad Aslam University of Agriculture - Department of Plant Pathology, Pakistan , Karar, Haider Ayub Agricultural Research Institute (AARI) - Cotton Research Station, Pakistan
Abstract :
In agroecosystem of canola, high intensity of aphidicides is used for the management of canola aphids in Pakistan. In canola crops, large varieties of coccinellid predators along with other entomophagous insects play their role in reducing aphid s population to a significant level. These entomophagous insect fauna remain under the non-target effects of insecticides used on canola crop. These studies were carried out to investigate the effects of Pyramid®, Advantage®, Curacron®, Mospilon® and imidacloprid on population of canola aphids and associated coccinellid predators. The results revealed an exposure-interval dependent variation in the population reduction of canola aphids. Population reduction in aphid on treated canola gradually increased with an increase in exposure interval during 2010 and 2011. After an exposure interval of 24 hours, percent population reduction ranged from 15.6 to 42.3% and 16.6 to 45.3% in 2010 and 2011, respectively. However, percent population reduction of aphids on treated canola approached to 82.0-94.6% and 83.3-93.6% in 2010 and 2011, respectively after an exposure interval of 168 hours. After maximum exposure interval (168 hours), all of the evaluated insecticides induced more than 80% reduction in aphid s population; however, Mospilon® and Advantage® caused more than 90% reduction after 168 hour post treatment. The results regarding performance of insecticides against coccinellid predators showed that toxicity of insecticides residues persisted upto 72 hours as percent population reduction increased upto this exposure interval and then a decline in population reductions of coccinellid predators after 168 hours of post treatment was observed during both observation years. After an exposure period of 24 to 72 hours, Mospilon® was found comparatively more toxic to coccinellid predators as it caused very acute knockdown toxicity (90.2-93.7% and 80.9-91.9% during 2010 and 2011, respectively) for these interval followed by Curacron® with acute knockdown toxicity of 72.5-93.8% and 75.1-93.4% during 2010 and 2011, respectively. Pyramid®, Advantage® and imidacloprid showed chronic residual toxicity against coccinellid predators. These results show that Pyramid®, Advantage® and imidacloprid can be used in canola agroecosystem where integration of insecticides and coccinellid-predators based IPM strategy is to be implemented for aphid management on canola crops.
