Lychee pollination by the honeybee

Abstract

Pollination of lychee (Litchi chinensis Sonn. ) by the honeybee was studied in Israel's two commercial cultivars, 'Mauritius' and 'Floridian'. Pollination rate, which was determined in a mixed 'Mauritius' and 'Floridian' plot, followed a consistent pattern: it was low at the first male (M1) 'Mauritius' bloom and reached a high value only when the pseudohermaphroditic (M2) 'Mauritius' bloom started. Pollen density on bees collected from 'Mauritius' inflorescences was very low during the M1 bloom and increased to very high values during the M2 bloom. These results indicate that the 'Mauritius' M1 bloom does not play an important role as a source of pollen for pollination. Pronounced, significant, and consistent differences in nectar volume per flower and sugar concentration in the nectar were found between M1. M,. and female (F) 'Mauritius' flowers. Values were very high in F flowers, medium in M2 flowers, and low in M1 flowers. Accordingly, the density of bees found on inflorescences was high during the F bloom, intermediate during the M2 bloom, and low during the M1 bloom. The positive correlation between bee density and sugar concentration in the nectar was highly significant for M2 and F 'Mauritius' flowers. The nectar contained three sugars: glucose (43%), fructose (39%), and sucrose (18%). This ratio was the same in nectar from M1, M2, and F 'Mauritius' flowers.