title: Influence of honey bee, Apis mellifera, hives and field size on foraging activity of native bee species in pumpkin fields.
abstract: The purpose of this study was to identify bee species active in pumpkin fields in New York and to estimate their potential as pollinators by examining their foraging activity. In addition, we examined whether foraging activity was affected by either the addition of hives of the honey  bee, Apis mellifera L., or by field size. Thirty-five pumpkin (Cucurbita spp.) fields ranging from 0.6 to 26.3 ha, 12 supplemented with A. mellifera hives and 23 not supplemented, were sampled during peak flowering over three successive weeks in 2008 and 2009. Flowers from 300 plants per field  were visually sampled for bees on each sampling date. A. mellifera, Bombus impatiens Cresson, and Peponapis pruinosa (Say) accounted for 99% of all bee visits to flowers. A. mellifera and B. impatiens visited significantly more pistillate flowers than would be expected by chance, whereas P.  pruinosa showed no preference for visiting pistillate flowers. There were significantly more A. mellifera visits per flower in fields supplemented with A. mellifera hives than in fields not supplemented, but there were significantly fewer P. pruinosa visits in supplemented fields. The number  of B. impatiens visits was not affected by supplementation, but was affected by number of flowers per field. A. mellifera and P. pruinosa visits were not affected by field size, but B. impatiens visited fewer flowers as field size increased in fields that were not supplemented with A. mellifera  hives. Declining A. mellifera populations may increase the relative importance of B. impatiens in pollinating pumpkins in New York.
authors.affiliation: Department of Entomology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, USA. dra54@cornell.edu
authors.forename: Derek R
authors.initials: DR
authors.lastname: Artz
authors.forename: Cynthia L
authors.initials: CL
authors.lastname: Hsu
authors.forename: Brian A
authors.initials: BA
authors.lastname: Nault
mesh_terms: D000383:Agriculture; D000818:Animals; D001070:Appetitive Behavior; D001516:Bees; D028464:Cucurbita; D005247:Feeding Behavior; D005260:Female; D035264:Flowers; D016014:Linear Models; D008297:Male; D057048:Plant Nectar; D054817:Pollination
chemical_list: D057048:Plant Nectar