The effect of food profitability on foraging behaviors and vibrational signals in the African stingless bee Plebeina hildebrandti

摘要

The study of stingless bee foraging strategies and communication about food sources focused mainly on neotropical species. African stingless bees have received much less attention by researchers. Our study aims to fill this gap and, therefore, focuses on the African stingless bee Plebeina hildebrandti. Food profitability appears to influence various aspects of the foraging process in stingless bees. To study the effect of food profitability on the foraging process, we trained foragers to artificial feeders containing different food qualities and studied the individual foraging process with respect to food uptake, foraging cycles, as well as food transfer to nestmates. Our results indicate that foragers of P. hildebrandti adjust foraging behaviors according to the food profitability in a way that may increase colony's efficiency. Furthermore, we studied the influence of different food qualities on the vibrational signals produced by foragers during food transfer. Signal duration, pulse duration, and duty cycle appear to be adjusted according to the food quality, i.e., profitability. We measured the duration potential recruits which have direct contact to the forager and asked whether this time is long enough to gain profitability information from the vibrational signals. The informational value of the vibrational signals is discussed.