The Comparison Of Sensitivity On Sugars In Apis Cerana And Apis Mellifera

Honeybee is a kind of eusocial insect. Individuals have different divisions of labor in the colony. Apis cerana can make better use of scattered nectar source than Apis mellifera. In order to study the mechanism of this phenomenon, the method of PER was determined to test and compare the sensitivity to sucrose in Apis cerana and Apis mellifera. The score of proboscis extension reflex to glucose, fructose and trehalose of foragers of Apis cerana and Apis mellifera were tested. In order to study whether the difference on the score of PER was derived from environment, three mixed-species colonies were built. At last, the concentration of the nectar collected by nectar foragers of both kinds of honeybees was tested and analyzed. The major results were summarized as follows:1. The comparative study of PER of foragers come from Apis cerana and Apis mellifera:There was a positive correlation between score of PER and concentration of sucrose(F=170.390, P<0.0001), which were0.1%,0.3%,1%,3%,10%and30%. Sensitivity to sucrose of Apis mellifera was higher than that of Apis cerana. Pollen foragers were more sensitive than non-pollen foragers. The score of PER to30%sucrose to forager in Apis mellifer almost reached100%, while that of pollen foragers of Apis cerana was about80%, the score of non-pollen foragers of Apis cerana is about60%. The sensitivity to sucrose of non-pollen foragers in Apis mellifera was significant higher than non-pollen foragers in Apis cerana (P<0.0001).2. Comparative study of the PER score of foarers to sucrose, glucose, fructose and trehalose of Apis cerana and Apis mellifera:there was a positive correlation between score of PER and concentration of sucrose, glucose, fructose and trehalose. There was significant difference in the PER test to sucrose, glucose, fructose and trehalose. The order of sensitivity to this four sugars from high to low was sucrose, fructose, glucose, trehalose to Apis cerana, while the order to Apis mellifera was sucrose, glucose, trehalose, fructose. Apis mellifera have significantly low sensitivity to fructose and trehalose, while the sensitivity to sucrose and glucose was high for foragers of Apis mellifera. The content of fructose in nectar was high, and foragers of Apis cerana were more sensitive than A.M. This may be one of the reasons that Apis cerana can make good use of scattered nectar. 3. Mixed-species colony experiment:three mixed colonies were operated by bees come from Apis cerana and Apis mellifera, the first and second mixed-species clonies had a queen of Apis cerana, the third mixed-species clony had a queen of Apis mellifera. The1day-aged bees were marked before mixed. The score of PER of14-day-aged and21-day-aged bees were tested. The result showed that:Apis mellifera14-day-aged were more sensitive than Apis cerana at the same age (F=18.894, P=0.0122, P<0.05). The result of PER of21-day-aged bees suggested that there was significant difference between the sensitivity to sucrose among Apis cerana and Apis mellifera (F=14.875, P=0.0048, P<0.01), Apis mellifera21-day-aged were more sensitive than Apis cerana at the same age. This showed that the difference of PER of foragers was not caused by different colony environment in Apis cerana and Apis mellifera.4.The comparation of the concentration of nectar collected by foragers:the mean sugar content in nectar varied significantly from9:00to17:00in both species (F=2.210, P=0.032), while the average sugar content of bees collected each hour from Apis cerana foraged nectar was not significantly different from Apis mellifera (F=0.057, P=0.8118, P>0.05). The lowest sugar content of each hour were also not significantly different between the two species (F=1.037, P=0.3109).