Field use of an incubation box for improved emergence timing of Osmia lignaria populations used for orchard pollinationTheresa L. Pitts-Singer1, Jordi Bosch2, William P. Kemp3 and Glen E. Trostle1
1 USDA-ARS Bee Biology & Systematics Laboratory, Utah State University, Logan, Utah 84326, USA
2 Ecologia-CREAF, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
3 USDA-ARS RRVARC, 1605 Albrecht Blvd., PO Box 5674, University Station, Fargo, ND 58105-5674, USA
(Received 29 May 2007 - Revised 12 October 2007 - Accepted 24 October 2007 - Published online 12 February 2008)
Abstract - Wintered populations of blue orchard bees, Osmia lignaria, may require incubation to time emergence to crop bloom. In this study, bee nests were placed in an almond (California) and an apple (Utah) orchard under two incubation treatments: in wood blocks and field incubation boxes. Loose cocoons were also placed in the boxes. Incubation boxes had heating units (set to max. temperature = 22 °C) to increase or prolong daytime temperatures to higher than ambient ( 14 °C higher in Utah). Bee emergence was monitored, and temperatures were recorded. The incubation boxes allowed for faster accumulation of heat units compared to wood blocks. Bees survived well under all conditions (> 90% emergence). Compared to bees in wood blocks, females in incubation boxes required three days less in CA and eight days less in Utah for 50% emergence. Results show the utility of heated incubation boxes for shortening O. lignaria emergence time, helping to synchronize bee emergence with bloom initiation.
Key words: Megachilidae / Osmia lignaria / blue orchard bee / incubation / pollination
© INRA, DIB-AGIB, EDP Sciences 2008