title: Supercooling points and diapause termination in overwintering adults of orchard bees Osmia cornuta and O. rufa (Hymenoptera: Megachilidae).
abstract: The orchard bee species Osmia cornuta (Latreille) and O. rufa (Linnaeus) are both European in distribution. Osmia cornuta is distributed in the central and southern half of the continent, while O. rufa is distributed additionally in more northern parts of Europe, including Great Britain. These bees over-winter in cocoons as diapausing adults. The freezing temperatures of overwintering adults of O. cornuta and O. rufa during diapause are similar: -30 degrees C to -24 degrees C and -31 degrees C to -26 degrees C, respectively. However, there are differences in the termination of their diapause. Under natural conditions in the wider area of Belgrade, O. rufa appears in spring about two weeks later than O. cornuta.
authors.affiliation: Institute of Zoology, Faculty of Biology, University of Belgrade, Studentski trg 16, 11000 Belgrade, Serbia and Montenegro.
authors.forename: M D
authors.initials: MD
authors.lastname: Krunić
authors.forename: L Z
authors.initials: LZ
authors.lastname: Stanisavljević
mesh_terms: D000818:Animals; D001516:Bees / Q000502:physiology*; D005260:Female; D005615:Freezing; D008297:Male; D012044:Regression Analysis; D012621:Seasons; D013045:Species Specificity; D015022:Yugoslavia