Post on 10-Jan-2016
description
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Economic Viability of a Varroa IPM System
Keith S. Delaplane, James D. Ellis University of Georgia
www.ent.uga.edu/bees
Concluded
Colonies with resistant queens and screen bottoms tend to:
• Have fewer mites, especially at seasons when mite depredation is most severe,
• Have delayed onset of economic threshold.
. . . and detected
Favorable compensatory interactions:
• Between resistant queens and screens,
• Between queens and screens and non-isolated apiaries.
Design
Design
• 2 years
Design
• 2 years
• 6 beekeeper collaborators
Design
• 2 years
• 6 beekeeper collaborators
• 21-30 colonies each
Design
• 2 years
• 6 beekeeper collaborators
• 21-30 colonies each
• 3 treatments within apiary
Design
• 2 years
• 6 beekeeper collaborators
• 21-30 colonies each
• 3 treatments within apiary– chemical: Feb and Aug chemical
Design
• 2 years
• 6 beekeeper collaborators
• 21-30 colonies each
• 3 treatments within apiary– chemical: Feb and Aug chemical
– IPM: bottom screen + Russian
Design
• 2 years
• 6 beekeeper collaborators
• 21-30 colonies each
• 3 treatments within apiary– chemical: Feb and Aug chemical
– IPM: bottom screen + Russian – Control: no chemical or IPM, non-selected
Design
• Monitored:– Mite fall– Onset of threshold– Honey yield– Time spent working colonies– Queen loss (replaced as found)
0
10
20
30
40
50
60
70
month
mit
es o
n st
icky
she
et (2
4 h)
s
Control
Chemical
IPM
Varroa counts, 24-h mite drop
Excluding colonies treatment threshold
2005 2006
17 .9
1 3 .1
2 1 .3
0
1 0
2 0
3 0
4 0
C o n tr o l C h e m ic a l IP M
mit
esV a rro a c o u n ts , a v e ra g e d
7469
94
0
10
20
30
40
50
60
70
80
90
100
Control Chemical IPM
%
Percent colonies reaching threshold at least once in two years
60 mites / 24-hr; Delaplane and Hood 1997, 1999
33593078
3222
0
500
1000
1500
2000
2500
3000
3500
Control Chemical IPM
poun
ds2005 season honey production (pounds)
2053
1104
660
0
500
1000
1500
2000
2500
3000
3500
Control Chemical IPM
poun
ds2006 season honey production (pounds)
254226
262
0
25
50
75
100
125
150
175
200
225
250
275
300
Control Chemical IPM
seco
nds
Average time spent working colony (seconds)
446
534
418
0
50
100
150
200
250
300
350
400
450
500
550
600
Control Chemical IPM
visi
tsTotal number colony visits
40.4
33.530.4
0
10
20
30
40
50
Control Chemical IPM
hour
sTotal time spent working colonies (hours)
40.4
33.530.4
0
10
20
30
40
50
Control Chemical IPM
hour
sTotal time spent working colonies (hours)
screens
31.5Colony work
39
61
72
0
10
20
30
40
50
60
70
80
90
100
Control Chemical IPM
%Percent of colonies dead after 2 years
46
54
48
0
10
20
30
40
50
60
Control Coumaphos IPM
% o
f col
onie
sRequeening Rate, period 1% colonies requeened, Feb-Aug 2005, n=54
39
46
55
0
10
20
30
40
50
60
Control Chemical IPM
% o
f col
onie
sRequeening Rate, period 2
% colonies requeened, 2005 Aug-Apr 2006, n=33-49
Conclusions
Compared to control colonies or chemical colonies, IPM colonies:
Conclusions
Compared to control colonies or chemical colonies, IPM colonies:
• Compared favorably for average mite levels,
17.9
13.1
21.3
0
10
20
30
40
Control Chemical IPM
%
Varroa counts, averaged
Conclusions
Compared to control colonies or chemical colonies, IPM colonies:
• Compared favorably for average mite levels,
• Compared favorably for onset of threshold,
17.9
13.1
21.3
0
10
20
30
40
Control Chemical IPM
%
Varroa counts, averaged
7469
94
0
10
20
30
40
50
60
70
80
90
100
Control Chemical IPM
%
Percent colonies reaching threshold at least once in two years
60 mites / 24-hr; Delaplane and Hood 1997, 1999
Conclusions
Compared to control colonies or chemical colonies, IPM colonies:
• Had highest honey production,2053
1104
660
0
500
1000
1500
2000
2500
3000
3500
Control Chemical IPM
poun
ds
2006 season honey production (pounds)
Conclusions
Compared to control colonies or chemical colonies, IPM colonies:
• Had highest honey production,
• Had highest total work hours,
2053
1104
660
0
500
1000
1500
2000
2500
3000
3500
Control Chemical IPM
poun
ds
2006 season honey production (pounds)
40.4
33.530.4
0
10
20
30
40
50
Control Chemical IPM
hour
s
Total time spent working colonies (hours)
Conclusions
Compared to control colonies or chemical colonies, IPM colonies:
• Had highest honey production,
• Had highest total work hours,
• Fewest colony deaths, and
2053
1104
660
0
500
1000
1500
2000
2500
3000
3500
Control Chemical IPM
poun
ds
2006 season honey production (pounds)
40.4
33.530.4
0
10
20
30
40
50
Control Chemical IPM
hour
s
Total time spent working colonies (hours)
39
61
72
0
10
20
30
40
50
60
70
80
90
100
Control Chemical IPM
%
Percent of colonies dead after 2 years
Conclusions
Compared to control colonies or chemical colonies, IPM colonies:
• Lowest queen replacement rate.
39
46
55
0
10
20
30
40
50
60
Control Chemical IPM
% o
f col
onie
s
Requeening Rate, period 2% colonies requeened, 2005 Aug-Apr 2006, n=33-49
46
54
48
0
10
20
30
40
50
60
Control Coumaphos IPM
% o
f col
onie
s
Requeening Rate, period 1% colonies requeened, Feb-Aug 2005, n=54