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 (M,) `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 M, bloom and increased to very high values during the M2 bloom. These results indicate that the `Mauritius' M, 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, M2, and female (F) `Mauritius' flowers. Values were very high in F flowers, medium in M2 flowers, and low in M, 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.