MANAGEMENT OF THE ALFALFA LEAFCUTTING BEE, MEGACHILE-ROTUNDATA (HYMENOPTERA, MEGACHILIDAE), FOR POLLINATION OF WILD LOWBUSH BLUEBERRY

The alfalfa leafcutting bee (Megachile rotundata F.) was investigated as an alternative pollinator to the honey bee (Apis mellifera L.) of w ild lowbush blueberry (Vaccinium angustifolium Ait.). Pollinator effec tiveness and stacking density were determined by examining the effect of M. rotundata on fruit set in relation to foraging distance from the nesting shelter A significant relationship existed between distance f rom individual nesting shelters and percent fruit set for nine of 15 s helters. Megachile rotundata improved fruit set by as much as 30% over background pollination (pollination provided by honey bees and native bees). A recommended stocking density of 49,420 bees/ha was estimated . Fruit set was significantly higher in m(2) plots visited by migrator y M. rotundata (forage provided before blueberry bloom) than in plots visited by nonmigratory M. rotundata (no forage provided before bloom) . Overall reproductive ratio was less than 0.2 loose cells produced to loose cells incubated. The alfalfa leafcutting bet: can be a suitable and cost-effective alternative to the honey bee for pollination of V. angustifolium, but will probably need to be purchased annually.