BeeSource.com | POV | USDA | Natural Suppression of Honey Bee Tracheal Mites In North Dakota: A Five Year Study

Table 1. Honey bee tracheal mite infestation levels among overwintered units: 1989-1994.

Treatment
3/90
10/90
4/91
10/91
3/92(1)
4/93(1)
4/94(2)
4/95

Small Cell
% units w/mites
30
18
8
11
7
0
14
59

N =
20
33
26
28
28
31
28
22

Mean # Bees w/mites for infested samples(2)
1.3
1.2
1.0
1.0
1.0
-
1.2
2.1

Large Cell
% units w/mites
29
23
12
0
3
0
10
55

N =
17
30
25
30
29
33
29
27

Mean # Bees w/mites for infested samples(2)
1.4
1.6
1.3
-
2.0
-
1.0
3.7

(1) Samples for 10/92 and 10/93 damaged during shipment.
(2) Sample size = 30.

Table 1. Honey bee tracheal mite infestation levels among overwintered units: 1989-1994.
Treatment	3/90	10/90	4/91	10/91	3/92(1)	4/93(1)	4/94(2)	4/95
Small Cell % units w/mites	30	18	8	11	7	0	14	59
N =	20	33	26	28	28	31	28	22
Mean # Bees w/mites for infested samples(2)	1.3	1.2	1.0	1.0	1.0	-	1.2	2.1

Large Cell % units w/mites	29	23	12	0	3	0	10	55
N =	17	30	25	30	29	33	29	27
Mean # Bees w/mites for infested samples(2)	1.4	1.6	1.3	-	2.0	-	1.0	3.7
(1) Samples for 10/92 and 10/93 damaged during shipment. (2) Sample size = 30.