Comparative assessment of hemolymph composition and bioactivity in different bee species

Abstract Background Hemolymph, as mediator of immune responses and nutrient circulation, can be used as physiological marker of an insect’s health, environmental quality or ecological adaptations. Recent studies reported intraspecific variation in protein contents and biological activities of the hemolymph of honey bees related to their diet. Here we measured interspecific variation in three common bee species in the Mediterranean Basin with contrasting ecologies: Apis mellifera , Megachile sicula, and Xylocopa pubescens . Results Despite all the bees were collected in the same area, we found important quantitative and qualitative variations of hemolymph extracts across species. Samples of A. mellifera and M. sicula had much higher protein concentration, anticancer, antimicrobial and antioxidant activities than samples of X. pubescens. Conclusions This descriptive study suggests life history traits of bee species have strong influences on their hemolymph properties and call for future large scale comparative analyses across more species and geographical areas.