Incidence and the control of the mango leaf webber, Orthaga euadrusalis Walker (Pyralidae: Lepidoptera) in Himachal Pradesh.
Ranjeet Bhatia, Divender Gupta
Author Affiliation: Regional Horticultural Research Station, Dr. Y.S. Parmar University of Horticulture and Forestry, Jachh, Teh. Nurpur, Distt. Kangra - 176 201, India.
Agricultural Science Digest 22 : 111-113
Abstract : Some 55 mango orchards in Kangra (29), Chamba (1), Hamirpur (15), and Una (10) districts in Himachal Pradesh, India, were surveyed in 1996 for O. euadrusalis infestation. The highest incidence of O. euadrusalis was observed in Kangra (20.53%), followed by Chamba (15.0%), Kamirpur (12.5%), and Una (8.3%). In Kangra, the greatest infestation was recorded for Ganoh (37.4%), followed by Dhameta (36.3%) and Sebrian (12.0%). In Una and Hamirpur, the infestation level was between 4.6 and 14.3% and between 10.8 and 13.4%, respectively. In Chamba, 15.0% of trees were infested. In 1998 and 1999, the efficacy of carbaryl (0.1%), chlorpyrifos (0.04%), cypermethrin (0.01%), endosulfan (0.05%), methyl parathion [parathion-methyl] (0.05%), and Bacillus thuringiensis (1 g/litre) against O. euadrusalis was evaluated. Cypermethrin was highly effective, giving pest reductions of 98.45 and 97.85% at 5 days after treatment and 96.86 and 95.63% at 15 days after treatment in 1998 and 1999, respectively. Carbaryl was equally effective, resulting in 96.80 and 97.89% control on the 5th day and 91.92 and 95.72% on the 15th day. The other insecticides, except B. thuringiensis, gave more than 85% control at 15 days post-treatment, but showed lesser efficacy thereafter. In contrast, B. thuringiensis recorded greater efficacy after 15 days than at 5 days after treatment.