2014 Southeast Hay Convention
Are some varieties better than others?
Are some regions worse than others?
The Bermudagrass Stem
Maggot: Are some varieties
better than others? Are some
regions worse than others? Introduction
Lisa Baxter
Graduate Research Assistant, University of Georgia
Introduction
•  Control strategies still very unclear
•  Cultural management is major part of IPM
− Previous work suggests damage is positively
correlated to canopy density (Ikeda et al., 1991)
•  Additional information is needed
− Susceptibility of bermudagrass cultivars to BSM
− Reproductive potential of the BSM
Results:
Results:
Effect of Cultivar on Number of
Infected Tillers with Flies Present
10
b
8
b
b
16%
Avg. Number of Infected
Tillers/Pot
Avg. Percent of Tillers
Damaged/Pot
a
12%
10%
b
6
14%
b
b
8%
b
6%
4
c
c
c
c
2
4%
2%
s
85
ar
gr
as
n
Columns followed by the same le2er are similar at the 0.05 level Lisa Baxter
Graduate Research Assistant
3.75
a
3.70
3.65
7%
3.60
3.55
3.50
b
3.45
3.40
3.35
“Actual Results May Vary!”
3.30
Without Flies
St
fto
n
68
Ti
Ti
ro
s
tc
Co
as
fto
sII
a
ici
Al
se
Ru
s
m
as
m
Co
Co
ll
0%
on
0
3.80
Avg. Total Dry Weight (g/pot)
18%
a
Avg. Percent of Tillers Damaged/Pot
aa
a
12
ta
l
Avg. Number of Infected Tillers/Pot
14
Effect of Fly Treatment on Average
Total Dry Weight
P = 0.01
Columns followed by the same le2er are similar at the 0.05 level 1
With Flies
P = 0.05
2014 Southeast Hay Convention
Are some varieties better than others?
Are some regions worse than others?
Methods- Objective 3:
Collection and Assessment
median oviduct
•  Collected from 12 locations
ovary
in Georgia and Florida
1.  central GA
2.  east GA
ovariole with
mature oocyte
3.  south GA
4.  FL
lateral
oviducts
developing oocytes
1 mm
Results:
Results:
Effect of region on the number of flies
on status of ovarioles
45
a
Total Avg. # of Ovarioles/Female
Number of Flies in Each Group
35
Effect of Region on the Total Avg.
Number of Ovarioles per Female
30
25
20
15
b
10
b
b
5
40
a
35
bc
30
b
c
25
20
15
10
5
0
Middle GA
East GA
South GA
Columns followed by the same le2er are similar at the 0.05 level FL
0
Middle GA
P = 0.01
Conclusions:
South GA
FL P = 0.01
Conclusions:
Preliminary Conclusions
Implications
•  Percent of tillers damaged and severity of damage
Plant a more tolerant cultivar such as Tifton
depends on cultivar
85 or Coastcross-II (if released)
•  Number and status of ovarioles depends on region
Lisa Baxter
Graduate Research Assistant
East GA
Columns followed by the same le2er are similar at the 0.05 level 2
2014 Southeast Hay Convention
Are some varieties better than others?
Are some regions worse than others?
Questions
Lisa Baxter
Graduate Research Assistant
3