TABLE 1.

Experimental inoculation of newly emerged bumblebees and honey bees as well as 4-week-old and mixed-age bumblebees with freshly isolated, viable N. ceranae spores

Expt	Bee species	Total no. of tested individuals	N. ceranae spore dosage per individual	% infected (mean ± SD) by microscopy	% detected (mean ± SD) by PCR	Duration of expt (days)	% survival (mean ± SD)
1	B. terrestris (newly hatched)	49	50,000	0	6.13 ± 0.21	14	95.9 ± 3.5
		60	0	0	0	14	86.7 ± 12.6
	A. mellifera (newly hatched)	60	50,000	100 ± 0	100 ± 0	14	88.3 ± 5.8
		60	0	0	0	14	91.7 ± 2.9
2	B. terrestris (newly hatched)	60	6,500	0		28	68.3 ± 16.1
		60	50,000	0		28	66.7 ± 28.9
		60	500,000	0		28	75.0 ± 5.0
		73	0	0		28	83.6 ± 3.8
3	B. terrestris (four weeks old)	30	50,000	0		45	90.0 ± 0.0
		30	0	0		45	90.0 ± 10.0
	B. terrestris (mixed age)	60	50,000	0	0	45	43.3 ± 2.1
		23	0	0	0	45	8.3 ± 1.5
4	B. terrestris (newly hatched)	30	>5,550,000	0	0	43	70.0 ± 0.0