@article{GrundMuellerRuedenauerSpaetheetal.2020,
  author    = {Grund-Mueller, Nils and Ruedenauer, Fabian A. and Spaethe, Johannes and Leonhardt, Sara D.},
  title     = {Adding amino acids to a sucrose diet is not sufficient to support longevity of adult bumble bees},
  series = {Insects},
  volume    = {11},
  journal   = {Insects},
  number    = {4},
  issn      = {2075-4450},
  doi       = {10.3390/insects11040247},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-203866},
  year      = {2020},
  abstract  = {Dietary macro-nutrients (i.e., carbohydrates, protein, and fat) are important for bee larval development and, thus, colony health and fitness. To which extent different diets (varying in macro-nutrient composition) affect adult bees and whether they can thrive on nectar as the sole amino acid source has, however, been little investigated. We investigated how diets varying in protein concentration and overall nutrient composition affected consumption, longevity, and breeding behavior of the buff-tailed bumble bee, Bombus terrestris (Hymenoptera: Apidae). Queenless micro-colonies were fed either natural nutrient sources (pollen), nearly pure protein (i.e., the milk protein casein), or sucrose solutions with low and with high essential amino acid content in concentrations as can be found in nectar. We observed micro-colonies for 110 days. We found that longevity was highest for pure pollen and lowest for pure sucrose solution and sucrose solution supplemented with amino acids in concentrations as found in the nectar of several plant species. Adding higher concentrations of amino acids to sucrose solution did only slightly increase longevity compared to sucrose alone. Consequently, sucrose solution with the applied concentrations and proportions of amino acids or other protein sources (e.g., casein) alone did not meet the nutritional needs of healthy adult bumble bees. In fact, longevity was highest and reproduction only successful in micro-colonies fed pollen. These results indicate that, in addition to carbohydrates and protein, adult bumble bees, like larvae, need further nutrients (e.g., lipids and micro-nutrients) for their well-being. An appropriate nutritional composition seemed to be best provided by floral pollen, suggesting that pollen is an essential dietary component not only for larvae but also for adult bees.},
  language  = {en}
}
@article{RuedenauerWoehrleSpaetheetal.2018,
  author    = {Ruedenauer, Fabian A. and W{\"o}hrle, Christine and Spaethe, Johannes and Leonhardt, Sara D.},
  title     = {Do honeybees (Apis mellifera) differentiate between different pollen types?},
  series = {PLoS ONE},
  volume    = {13},
  journal   = {PLoS ONE},
  number    = {11},
  doi       = {10.1371/journal.pone.0205821},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177537},
  pages     = {e0205821},
  year      = {2018},
  abstract  = {Bees receive nectar and pollen as reward for pollinating plants. Pollen of different plant species varies widely in nutritional composition. In order to select pollen of appropriate nutritional quality, bees would benefit if they could distinguish different pollen types. Whether they rely on visual, olfactory and/or chemotactile cues to distinguish between different pollen types, has however been little studied. In this study, we examined whether and how Apis mellifera workers differentiate between almond and apple pollen. We used differential proboscis extension response conditioning with olfactory and chemotactile stimulation, in light and darkness, and in summer and winter bees. We found that honeybees were only able to differentiate between different pollen types, when they could use both chemotactile and olfactory cues. Visual cues further improved learning performance. Summer bees learned faster than winter bees. Our results thus highlight the importance of multisensory information for pollen discrimination.},
  language  = {en}
}