The nesting behaviour of the mason bee Osmia cornuta (Latr) with special reference to its pollinating potential (Hymenoptera, Megachilidae)J. Bosch
Dept Biologia Animal, Fac Biologia, Univ Barcelona, Diagonal, 645, 08028 Barcelona, Spain
Abstract - The nesting behaviour of Osmia cornuta was studied in managed populations released in almond orchards. A correlation between the dry weight of a provision and the number of pollen grains in the provision was established. Male and female provisions contain a mean of 4 634 304 and 8 046 425 almond pollen grains, respectively. A correlation between the dry weight of a provision and the number of foraging trips was also established. The mean number of foraging trips necessary to complete a provision was 16.76 for male provisions and 26.79 for female provisions. During an almond blooming period, each O cornuta female potentially visits from 9 500 to 23 600 almond flowers. Given the pollinating efficiency of O cornuta on almond, 3 females per tree are considered sufficient to maximize pollination in an almond orchard.
Key words: Osmia cornuta / nesting behaviour / pollination / Prunus amygdalus