Overwintering management of Osmia lignaria 



JESO Volume 139, 2008 



(Fig. 6): on 12 Dec 2001 the temperature ranged between -2°C and 10°C; 07 Feb 2002 the 

 temperature ranged between 0°C and 11°C; 16 Mar 2002 the temperature ranged between 

 -3°C and 8°C. The corresponding temperatures recorded inside the nesting tubes had a 

 range falling within those observed within the chamber, but followed the same trend. 



Temperatures within the screened insectary (outside) showed large fluctuations 

 between night (daily minimums) and day (daily maximums); on several instances 

 throughout the winter a range of 20°C was observed within a 24 h period (Fig. 6). The 

 lowest temperature recorded was below -20°C, observed on 12 Feb 2002. More than half 

 the days in Jan-Feb 2002 stayed below 0°C; Dec 2001 and Mar 2002 had most daytime 

 temperatures above 0°C and night time temperatures below 0°C. In Apr and May 2002, 

 temperatures seldom fell below freezing. 



IS 30 



I* 



a a a 



Day (2001 -2002) 



FIGURE 6. Maximum and minimum ambient air (solid lines) and nesting tunnel temperatures 

 (dashed lines) within an environmental cabinet maintained at 4°C (top row) and within an 

 unheated screened insectary (bottom row) from Dec 1, 2001 to May 31, 2002. 



Emergence and Bloom Phenology 



Bees from both populations had similar emergence patterns, although the sex 

 ratio of bees from Nova Scotia was highly male biased (Fig. 7a). Male emergence began 

 approximately 01 May 2002, with most individuals emerged within one week. Female 

 emergence began approximately one week later than males, its start corresponding to 

 the peak of male emergence. Female emergence peaked approximately ten days prior to 

 commencement of the bloom period of Mcintosh apples (Fig. 7). 



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