Foraging Rate of Apis mellifera and Apis florea on Different Cultivars of Brassica
Braj Kishor Prasad Singh *
Department of Zoology, Babasaheb Bhimrao Ambedkar Bihar University, Muzaffarpur-842001, Bihar, India.
Prabal Chatterjee
Ramdayalu Singh College, Babasaheb Bhimrao Ambedkar Bihar University, Muzaffarpur-842001, Bihar, India.
*Author to whom correspondence should be addressed.
Abstract
This study evaluated the foraging rates of Apis mellifera and Apis florea on nine cultivars of Brassica crops under field conditions at Mushari block, Muzaffarpur district, Bihar, during the 2022-23 and 2023-24 rabi seasons. Three cultivars each of Brassica juncea var. raya, Brassica campestris var. tori, and Brassica campestris var. sarson were grown in 2 m x 4 m plots following locally recommended agronomic practices. Foraging observations were recorded at seven-day intervals between 21 December and 18 January during morning and evening flowering periods. The data were analysed using a factorial randomised block design with three replications, and treatment means were compared at the 5% significance level. Across the evaluated cultivars, A. florea consistently showed higher flower-visitation rates than A. mellifera. The highest recorded rates for both bee species occurred on Rajendra Sarson-1, followed by T-9 and Pusa Bold. In 2022-23, A. florea reached 21.25 flowers/minute on Rajendra Sarson-1, while A. mellifera reached 15.50 flowers/minute; corresponding values in 2023-24 were 20.95 and 15.31 flowers/minute. The lowest A. florea values in 2023-24 occurred on Varuna, Panchali, and Jhumka within the respective crop groups. Year, species, variety, and species-by-variety interaction significantly affected foraging rate. These findings demonstrate cultivar- and species-related variation in Brassica visitation under the local study conditions.
Keywords: Apis mellifera, Apis florea, Brassica juncea, Brassica campestris, foraging rate, flower visitation, rapeseed, mustard, cultivar, pollination ecology