Arrangement of new and used nesting materials in leafcutting bee, Megachile rotundata (F.) (Hym., Megachilidae), shelters to maximise cell production¹

Abstract

Each year, some new nesting material is required to replace damaged material or to accommodate an increase in the population of leafcutting bees, Megachile rotundata (F.) used for pollination. This study was conducted to determine whether new and used wood and polystyrene, which are used extensively in western Canada, should be isolated in separate shelters or mixed. It was found that new and used materials should be kept in separate shelters. Furthermore, while a small reduction in cell production does occur in polystyrene when together with wood, the reduction is less than that brought about by having new and used material in the same shelter. Zusammenfassung Untersuchungen zum Angebot von neuem und gebrauchtem Nestbaumaterial für die Blattschneiderbiene, Megachile rotundata (F.) (Hym., M egachilidae) im Hinblick auf eine maximale Zellenproduktion In jedem Jahr wird neues Nestbaumaterial benötigt, um es gegen beschädigtes Material auszutauschen, oder um die Nestgröße einer gestiegenen Volkgröße der Blattschneiderbiene, Megachile rotundata, anzupassen. Diese Untersuchungen wurden durchgeführt, um zu prüfen, ob neues oder gebrauchtes Holz und Styropor, die in Westkanada in großem Umfang zum Einsatz kommen, gemeinsam oder getrennt verwendet werden sollen. Es konnte ermittelt werden, daß neues und gebrauchtes Material getrennt verwendet werden soll. Weiterhin konnte festgestellt werden, daß die gewisse Reduktion der Zellenproduktion, die zu beobachten ist, wenn Styropor gemeinsam mit Holz verwendet wird, nicht so hoch ist wie bei der gleichzeitigen Verwendung von gebrauchtem und neuem Nestbaumaterial.

A preliminary analysis of the floral preferences of the Afalfa Leafcutting Bee, Megachile rotundata

“…This length approximates the combined body, head, and extensible mouthparts length of the bee. A floral length of 13.5 mm for a number of plant species with narrow corolla tubes was found mechanically to prevent Alfalfa Leafcutting Bees from reaching the basal nectaries (Fairey and Lefkovitch 1993). It should be stressed, however, that almost all of the 94 species with corol- las longer than 13.5 mm presented no obvious mechanical barriers to the bees to collection of pollen and/or nectar.…”

“…There is evidence that, for some flowers with a fairly narrow corolla tube, a corolla length of more than 13.5 mm is too long in relation to the body length of the female bees (9.1 mm, range 8-10.5 mm, plus length of mouthparts of ca. 4.5 mm) for the bees to reach the nectaries (Fairey and Lefkovitch 1993). Many of the plant species tested did not have narrow corolla tubes, or lacked corolla tubes, and so the bees could have reached nectaries without difficulty.…”