NECTAR SECRETION BY TORIA (BRASSICA CAMPESTRIS L. v. TORIA) AND FORAGING BEHAVIOUR OF THREE APIS SPECIES ON TORIA IN BANGLADESH
DOROTHY C. MURRELL AND WILLIAM T. NASH
Nectar secretion by toria florets reached a peak at about 9 h and decreased thereafter. Anthesis also occurred in the early morning. Apis ftorea appeared on the crop later. and in smaller numbers, than A. cerana, and spent more time on one floret. Apis dorsata was intermediate in foraging speed. Most bees of all species collected both nectar and pollen, but pollen collection by A. cerana was observed only in the morning. The highest proportion of A. cerana foragers carrying pollen loads followed shortly after anthesis. Maximum numbers of foragers were observed at 10.30 h for A. cerana and at 12.30 h for A. florea.