Ovarian development in the alfalfa leafcutter bee, egachile rotundata
K W Richards
Ovarian development in Megachile rotundata was studied in field-free, field-caged and laboratory-confined females in Alberta, Canada. Most of the increase in oocyte volume occurred during the second week after emergence. During the first seven days after emergence, females in the field fed on pollen and nectar and mated. Females in the laboratory had no access to pollen or to males, but half of them had access to honey. The presence of pollen in the diet appeared to stimulate vitellogenesis; a diet of honey alone or mating did not stimulate oocyte enlargement. There was a 70-fold increase in volume during oocyte development. The mean oocyte number per female increased two-fold during the main reproductive period compared with the number of oocytes in postemergence or older females. The implications of these results for improved management and productivity of M. rotundata are discussed.