Effect of L-Tryptophan on behavioral characteristics and function in honeybees (Apis mellifera meda L. )

This study conducted to evaluate the effects of L- Tryptophan on performance and defensive behavior of honeybees (Apis mellifera meda </em>L.). For this purpose, in a completely randomized design experiment; 25 beehives with same population and same aged half sib queens of Meda breed were randomly distributed in to five treatments and five replications so that each experimental unit were consist of 20000 boxes. Five experimental groups were containing bees nourished by syrups with 0, 750, 1500, 2250 and 3000 mg/litter L-Tryptophan for 2 months. The honey production measured and defensive behavior evaluation by installing a black leather bull in front of each boxes and counting stringed points on it per minute.  The results of Duncan’s test showed that the most of honey production related to bees fed syrup containing 2250 mg/litter L-tryptophan and in this treatment defensive behavior were significantly lower (P<0/01) than bees that did’nt consume tryptophan. However, population significantly decreased (P<0/05) in bees fed syrup containing 2250 mg/litter L-tryptophan comparing with bee’s did’nt consume tryptophan.