Effect of over-wintering and incubation temperatures on adult emergence in Osmia cornuta Latr (Hymenoptera, Megachilidae)J. Bosch and M. Blas
Dept Biologia Animal, Fac Biologia, Univ Barcelona, Diagonal 645, 08028 Barcelona, Spain
Abstract - Cocoons of the potential orchard pollinator Osmia cornuta were exposed to different over-wintering and incubation temperatures to see if adult emergence could be manipulated and bees could be induced to emerge in synchrony with almond bloom. Bees over-wintered in a warehouse in an almond-growing area emerged over a period of time longer than the blooming period of commercial almond orchards. Conversely, bees over-wintered in refrigerators completed emergence in less than a week. Longer over-wintering periods yielded shorter emergence periods, but lower over-wintering temperatures did not. Incubation of over-wintered cocoons for 24 h failed to consistently accelerate emergence. The shortest emergence periods were obtained when bees were over-wintered at 3°C for 120 d.
Key words: Osmia cornuta / over-wintering-temperature / emergence / pollination / Prunus amygdalus