| Abstract: | To study the effects of brood pheromone esters (three aliphatic esters, i.e., methyl palmitate, ethyl palmitate and ethyl oleate ) on development and foraging behavior of Apis cerana cerana workers), 1 day-old workers were fed with different food, of which the treatment group workers were fed with food (candy) mixed with one of the aliphatic esters at 1% or 0.1% (w/w), the control group workers were fed with food (candy) without any aliphatic ester; then, the percentage of workers with developed ovary at two phases (7 and 14 day-old), the width of hypopharnyngeal glands of workers at six phases (3, 5, 7, 12, 18 and 21 day-old) and the first foraging age were tested. The results showed that (1) At 7 and 14 day-old, the workers fed with methyl palmitate (1%, 0.1%) with developed ovaries were less than the control group in queenless colony. At 14 day-old, the workers with developed ovaries treated with ethyl palmitate (0.1%) were significantly less than the control group in queenless colony. At 14 day-old, the workers fed with methyl palmitate (1%) and ethyl oleate (1%, 0.1%) were both significantly less than the control group in queen-right colony. (2) At 5 and 7 day-old, the widths of hypopharnyngeal glands of workers tested with methyl palmitate (1%, 0.1%) in queen-right colony were longer than the control group, while shorter than the control group at the later phases (12, 18 and 21 day-old). From 7 to 21 day-old, the hypopharnyngeal gland development of treated workers with ethyl oleate (1%, 0.1%) was shorter than that of the control group. (3) Of the three aliphatic esters, only methyl palmitate exerted a stronger effect, causing a significant delay to first foraging age. The results suggest that different brood pheromones of honeybee have different biological effects on development and foraging behavior of Apis cerana cerana workers. |
