TY - JOUR

T1 - Red mason bees cannot compete with honey bees for floral resources in a cage experiment

AU - Hudewenz, Anika

AU - Klein, Alexandra Maria

PY - 2015/11

Y1 - 2015/11

N2 - Intensive beekeeping to mitigate crop pollination deficits and habitat loss may cause interspecific competition between bees. Studies show negative correlations between flower visitation of honey bees (Apis mellifera) and wild bees, but effects on the reproduction of wild bees were not proven. Likely reasons are that honey bees can hardly be excluded from controls and wild bee nests are generally difficult to detect in field experiments. The goal of this study was to investigate whether red mason bees (Osmia bicornis) compete with honey bees in cages in order to compare the reproduction of red mason bees under different honey bee densities. Three treatments were applied, each replicated in four cages of 18 m3 with 38 red mason bees in all treatments and 0, 100, and 300 honey bees per treatment with 10-20% being foragers. Within the cages, the flower visitation and interspecific displacements from flowers were observed. Niche breadths and resource overlaps of both bee species were calculated, and the reproduction of red mason bees was measured. Red mason bees visited fewer flowers when honey bees were present. Niche breadth of red mason bees decreased with increasing honey bee density while resource overlaps remained constant. The reproduction of red mason bees decreased in cages with honey bees. In conclusion, our experimental results show that in small and isolated flower patches, wild bees can temporarily suffer from competition with honey bees. Further research should aim to test for competition on small and isolated flower patches in real landscapes.

AB - Intensive beekeeping to mitigate crop pollination deficits and habitat loss may cause interspecific competition between bees. Studies show negative correlations between flower visitation of honey bees (Apis mellifera) and wild bees, but effects on the reproduction of wild bees were not proven. Likely reasons are that honey bees can hardly be excluded from controls and wild bee nests are generally difficult to detect in field experiments. The goal of this study was to investigate whether red mason bees (Osmia bicornis) compete with honey bees in cages in order to compare the reproduction of red mason bees under different honey bee densities. Three treatments were applied, each replicated in four cages of 18 m3 with 38 red mason bees in all treatments and 0, 100, and 300 honey bees per treatment with 10-20% being foragers. Within the cages, the flower visitation and interspecific displacements from flowers were observed. Niche breadths and resource overlaps of both bee species were calculated, and the reproduction of red mason bees was measured. Red mason bees visited fewer flowers when honey bees were present. Niche breadth of red mason bees decreased with increasing honey bee density while resource overlaps remained constant. The reproduction of red mason bees decreased in cages with honey bees. In conclusion, our experimental results show that in small and isolated flower patches, wild bees can temporarily suffer from competition with honey bees. Further research should aim to test for competition on small and isolated flower patches in real landscapes.

KW - Cage experiment

KW - Competitive interactions

KW - Niche breadth

KW - Reproduction

KW - Resource overlap

KW - Ecosystems Research

UR - http://www.scopus.com/inward/record.url?scp=84945897620&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/40810552-3946-3817-a024-f9fccf942842/

U2 - 10.1002/ece3.1762

DO - 10.1002/ece3.1762

M3 - Journal articles

AN - SCOPUS:84945897620

VL - 5

SP - 5049

EP - 5056

JO - Ecology and Evolution

JF - Ecology and Evolution

SN - 2045-7758

IS - 21

ER -