Evaluation of inexpensive pollen substitute diets through quantification of haemolymph proteins

Abstract

Throughout much of South and Central America, Africanized honey bees tend to abscond during dearth periods. Consequently, there has been much interest in finding ways to secure colonies by artificial feeding. Based on locally-available ingredients, we tested five different protein diets against bee bread and sucrose syrup by measuring the amount of protein in the haemolymph of caged, newly emerged Africanized honey bees fed exclusively on one of these diets for seven days. The diets contained one or several of the following ingredients: sucrose, soy meal, rice meal, sugar-cane-alcohol distillery yeast, wheat meal, soy milk powder, and ground lentils. Sucrose, in the form of sugar syrup, was used as a protein-free control. One of the diets, which included soy milk powder as a major protein source, instead of soy meal, resulted in low haemolymph protein levels, similar to that of the sucrose diet. All of the other protein diets raised the haemolymph protein levels significantly above that of the newly emerged bees (approximately 20 – 28 versus an initial 14 mg/ml haemolymph). The haemolymph protein levels of bees fed with these pollen substitute diets were similar to those of bees fed on bee bread. The initial protein levels in the newly emerged bees were considerably higher than in previous studies done in Brazil, apparently because our study was conducted during the spring, when natural food sources are relatively abundant. Nevertheless, it was still possible to objectively compare the diets under these conditions.