Sporadic food competition with the African honey bee: projected impact on neotropical social bees

Abstract

ABSTRACTBee colonies in lowland forest in Panama were monitored for pollen and nectar harvest, pollen species utilization and nectar quality and quantity per returning forager. Despite sharing most pollen resources and nectar of the same quality with 20 introduced colonies of the African honey bee (Apis mellifera), native stingless bees of 12 species were largely unaffected by its activity. Pollen and nectar harvested by the honey bees were 10–200 times that procured by 17 stingless bee colonies. This discrepancy in total harvest and general lack of competitive effect is explained by a honey bee foraging area over 10 times that of the native bees, and apparent foraging shifts to escape competition with honey bees, thus reduced potential overlap in foraging sites.Seven cases of direct resource competition for pollen or nectar were documented, out of 31 tests. Rare periods of intensive harvest were diminished by competing African honey bees. Such harvest peaks lasted for only a few hours in 13 days of observation. Despite average duration of 4% foraging time for each species, peaks included as much as 51% total harvest. Calculations based upon colony populations, food stores and flight range show that if African honey bees persist at a density of 1 colony per km2, colonies of some stingless bee species may disappear after 10 years. Their chances of escaping food competition by taxonomic specialization on flowers seem slight.