Native Wild Bees Research Articles

Bombus impatiens (Hymenoptera: Apidae): an alternative to Apis mellifera (Hymenoptera: Apidae) for lowbush blueberry pollination.

The pollination effectiveness of the commercially reared bumble bee Bombus impatiens Cresson, was compared in field studies to the honey bee, Apis mellifera L., for lowbush blueberry, Vaccinium angustifolium Ait. A preliminary study indicated that B. impatiens had potential as an alternative pollinator. In a 3-yr study, percentage fruit set, percentage harvested berries, berry weight, and seeds per berry were compared in blueberry fields stocked at 7.5 A. mellifera hives per hectare to 5, 7.5, or 10 B. impatiens colonies per hectare. Percentage of harvested berries (yield) was significantly higher in fields stocked with B. impatiens at 10 colonies per hectare. No other parameters measuring pollinator effectiveness were significantly different at 5, 7.5, or 10 colonies per hectare. Flower handling time was significantly faster for B. impatiens and it more frequently collected blueberry pollen. All parameters of pollinator effectiveness were similar for B. impatiens, A. mellifera, and native wild bees in a follow-up study. Overall, B. impatiens was a suitable alternative to A. mellifera.

Bee Conservation and Increasing Osmia spp. in Maine Lowbush Blueberry Fields

Conservation of bees is of growing concern in many areas of the world due to their importance as pollinators. In northeastern North America at least eight species of Osmia (Megachilidae) pollinate Vaccinium angustifolium Ait, lowbush blueberry. Local populations of native wild bees in many Maine fields are presently below levels necessary to adequately pollinate the crop without reliance on rented honey bees. Nesting sites are an essential and often limiting resource for native bees. Since 1993 we have been investigating the effect of providing artificial nesting sites, wooden trap-nest blocks, on popula? tions. Visual estimates of Osmia spp. densities from m2 plot counts and sweep net samples during blueberry bloom indicate Osmia populations increased in two of the three fields that had trap-nest blocks provided. In contrast, popula? tions did not increase in the three fields where nesting blocks had been provided.

Foliar Herbivory Affects Floral Characters and Plant Attractiveness to Pollinators: Implications for Male and Female Plant Fitness

Foliar Herbivory Affects Floral Characters and Plant Attractiveness to Pollinators: Implications for Male and Female Plant Fitness

Forest application of the insecticide fenitrothion and its effect on wild bee pollinators (Hymenoptera: Apoidea) of lowbush blueberries ( Vaccinium SPP.) in Southern New Brunswick, Canada

Fenitrothion, an organophosphorus insecticide, has been used as a larvicidal spray against spruce budworm ( Choristoneura fumiferana (Clem.) Lepidoptera: Tortricidae) over wide areas of forest in New Brunswick, Canada, since 1969. The important pollinators of lowbush blueberries in the region are native wild bees. Populations of these insects appear to have been severely reduced on fields within areas adjacent to where Fenitrothion has been used and residues have been found in carcasses of both honey bees and native bees. From that evidence, together with high toxicity of Fenitrothion to bees, and the area covered by their foraging ranges, it is concluded that blueberry fields and their immediate surrounds received doses of the pesticide. Because blueberries require outcrossing by bees, it is believed that crop failures have, in part, been caused by drifts or indiscriminate applications, or both, of the pesticide.

The Feasibility of Introducing Squash Bees (Peponapis and Xenoglossa) Into the Old World

The introduction of honeybees from the Old World to the New has been of the utmost significance, for the pollination of agricultural crops as well as for honey and wax production. And in New Zealand, red clover seed crops failed until bumble bees were introduced from England. The New World, as well as the Old, is rich in native wild bees, and the present article discusses the question of introducing to the Old World from the New certain species of “squash bees”, so called because they are especially adapted for pollinating squashes and other species of Cucurbita (gourds, pumpkins and vegetable marrows).

Our Curious Callers, the Native Wild Bees

Our Curious Callers, the Native Wild Bees