Insect pollinators of litchi with special reference to foraging behaviour of honey bees

Abstract

An experiment was conducted in litchi orchard (Bombai variety) of Horticultural Research Station (latitude 22°56¢39²N and longitude 88°30¢56²E) of Bidhan Chandra Krishi Viswavidyalaya at Mandouri in Nadia district of West Bengal during February to March, 2019 to record the different insect pollinators with special reference to foraging behaviour of honey bees visiting litchi flowers. A total of 13 insect pollinators belonging to order Hymenoptera (comprising of 7 species viz., Apis dorsata, Apis mellifera, Apis cerana indica, Apis florea, Lassioglossum sp., Vespa tropica and Camponotus compressus), Diptera (comprising of 5 species viz., Episyrphus balteatus, Eristalis sp., Syrphus sp., Sacrcophaga sp. and Lucilia sericata) and Coleoptera (comprising of single species viz., Coccinella septumpunctata) were found to visit litchi flowers during the period of study. The abundance (percentage of insect fauna/inflorescence/5 min.) of Hymenopterans (77.71%) was maximum followed by Dipterans (22.27%). Among Hymenopterans, A. dorsata (50.11%) was predominant visitor followed by A. cerana indica (11.80%), A. florea (8.68%) and A. mellifera (7.12%). The foraging speed (time spent in sec. per flower per forager) was recorded maximum during 9-11 am while, minimum during 3-5 pm for all the honey bees. The mean foraging speed was found to be maximum in A. dorsata (4.64 sec) while A. florea (3.32 sec) showed lowest. On the contrary, the foraging rate (number of flowers visited per min. per forager) was found to be highest during 3-5 pm for all the honey bees and the maximum and minimum mean foraging rate was recorded in A. florea (12.29) and A. dorsata (10.54) respectively.