Bioefficacy of phytochemicals against Vespa orientalis L. and Oecophylla smaragdina F. infesting Apis mellifera L. colony

The field experiment were conducted in a replicated randomized block design in the Apiary of the Department of Agricultural Entomology, situated at Main Experiment Station of Horticulture Farm, Narendra Deva University of Agriculture & Technology, Kumarganj, Faizabad, Uttar Pradesh, India. The bio-efficacy of two neem formulations viz., neem oil and nimbecidine, against yellow banded brown wasp, Vespa orientalis Linn. and red ant, Oecophylla smaragdina Fab. infesting Apis mellifera Linn. colony were assessed during floral dearth period i.e. June to September, 2005–06. Both the formulations were applied to the bottom peripheral ring of the beehive @ 40 ml and 60 ml/week, keeping untreated control. Nimbecidine @ 60 ml/beehive was found to be superior, thereby reducing the incidence of wasps and red ants to the extent of 1.03 - 1.30 times and 1.50 - 24.20 times, respectively, as compared to untreated control. The repellants of neem oil and nimbicidine are most efficient for both wasp and red ants during lean period and it secures survival of weak colonies in the apiary by its repellency, and their effectiveness standard declining from the next day after application.