Jack Baldwin
Fangneng
Huang
Rogers Leonard
Steve Harrison
Ed Twidwell
Hessian Fly
ID/Management
in Wheat
Hessian fly Mayetiola destructor
Adults
•There are 4-6 generations each year.
•A generation takes about 35 days at 75 º
F, longer at cooler temperatures.
•Development occurs between 40-80 º F
Hessian fly eggs
Hessian fly larvae
2nd stage (L) and 3 stage (R)
Hessian fly puparia
 puparia
Larvae 
R. Ratcliffe Photo
Hessian fly puparia
1
2-3
3-4
Hessian Fly In Wheat
Fly damaged plants and/or tillers
More dead tillers, thin stand
Toxins in saliva cause stunting, plant
death, yield and quality losses
A thin stand of stunted plants (right) is a classic
symptom of Hessian fly infestation
Hessian Fly In Wheat
John Van Duyn - NC State Randy Weisz – NC State
Fly damaged plants and/or tillers
Hessian fly damage looks different, depending on
when the wheat was infested
sometimes a wide leaf blade is a symptom. Often
the wide blade has a blue-green hue.
Hessian fly damage looks different, depending on
when the wheat was infested
early infestation results in stunting so leaf blades
only partially emerge from the ground
Infested tillers often die, particularly when
subjected to cold stress in winter
Hessian fly puparia
infested in spring
infested in winter?
Hessian fly yield loss in
winter wheat
• Seedling early tiller stage:
– 1 larva completely stunts
and kills tiller
– Cold injury
• Jointing / Heading / grain
fill stage:
– Multiple larva per stems at
joints
– Stunts stem
– Weaken stem cause
lodging.
– Reduces grain filling / test
weight.
↓
Hessian fly yield loss in
winter wheat
• Seedling early tiller
stage:
– 5% - 8% infested tillers
• Heading / grain fill
stage:
– 15% - 20% infested
stems
– 10% @ $7.00+/bu
1998
440-83K acres
Ryegrass /winter wheat are
common for food plots in
southern “green fields”.
2007
613-228K acres
Winter Wheat Acreage and Losses to
Hessian Fly in Georgia (1972-2007)
Acreage
10000
$28M
9000
1400
8000
1200
7000

6000

800
5000
4000
600
400
 

3000
2000
200
1000
 Hessian fly outbreak years
06
20
04
20
02
20
00
20
98
19
96
19
94
19
92
19
90
19
88
19
86
19
84
19
82
19
80
19
78
19
76
19
74
0
19
72
0
$ Losses

1000
19
Harvested acres (x1000).
1600
$ Losses
Wheat Hessian Fly
Management Summary
for Georgia
David Buntin
Dept. of Entomology
UGA – Griffin Campus
2008
Hessian ‘fly-free’ planting dates to avoid fall damage
Effect of Spring Tillage on Hessian Fly
Emergence from Wheat Stubble
(From Chapin et al. 1992. J. Entomol. Sci. 27:293)
Hessian flies per trap..
30
a
ab
25
20
15
bc
c
10
5
d
0
No-till
Burn
Disk
Burn &
Disk
Plow
Hessian fly Suppression
(Wheat Stubble Management)
• Plant as far away from previous year’s wheat
stubble as possible.
• Bury stubble to prevent emergence.
• No-till = burn alone > disking > plow.
• Burning stubble will not kill pupae.
• Plant resistant varieties in previous years field.
Control Volunteer
Wheat
No-till Soybeans with
volunteer wheat
Only important
alternate host in GA
is little barley,
Hordeum pusillum
DO NOT use
susceptible wheat for
wildlife plots or as a
cover crop
Hessian Fly Parasitism in Winter Wheat in
Georgia – 1986/1987
Sample
Period
Parasitoid
Species
% Parasitism
October
P. hiemalis
9
0
January
P. hiemalis
27
4
March
P. hiemalis
57
4
May
H. destructor
E. allynii
23
5
North GA
South GA
Plant Resistance for Hessian Fly Control
When a population of Hessian flies overcomes the
host plant resistance, it is called a biotype.
Numerous plant resistance genes have been
identified for Hessian flies. As they are deployed,
new biotypes emerge.
It is important to know what biotypes are present
in order to choose the right Hessian fly "resistant"
variety
Hessian Fly Biotype Composition in
Southern Georgia (1986-2000)
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
?
1986
1989
1991
1996
2000
2008
Sources: R. Ratcliffe et al., USDA-ARS, Purdue Univ.
E
G
M
O
L
Other
Hessian fly biotypes 1996-2001
Roger Ratcliffe, now retired from the
USDA Hessian fly lab
Poplarville 1996
L, D, J
Percent:
Biotype L
Biotype O
Other
Insecticides for Hessian Fly
Di-Syston 15G and Thimet/Phorate 20G
are no long labeled for use on wheat.
• Gaucho 600
– 0.8 to 2.4 fl. oz. / 100 lb
• Gaucho XT
– 3.4 oz/100 lbs seed
– Raxil & Apron fungicides
• Cruiser 5FS (Wheat-Pak)
–
–
–
–
1 oz/100 lb seed
Contains 3 fungicides
Rate too low for HF
Max. 1.33 oz/100 lb seed
– Rate too low for HF
• Gaucho XT + Gaucho 600 @ • Karate Z (1.92 oz/A)
– @ 2-4 leaf stage.
1 oz/100 lb seed
– @ full tiller (early to mid March)
• Commercial seed treater
– Seed conditioner, dealer
– Suppression; Timing difficult
Hessian Fly Control by Insecticide
Treatments (Plains, GA)
Untreated
Gaucho 600 @ 1.2
DiSyston 15G
Gaucho 600 @ 1.6
Gaucho 600 @0.8
Warrior @ 30DAP
35
% Infested Tillers
30
25
20
15
*
10
5
*
*
*
*
1994/1995
1995/1996
0
*
1996/1997
*Significantly different from Untreated, P = 0.05.
Early spring Hessian fly control
with insecticide in fall infested wheat
Treatments*
•
•
•
•
Eggs/10 leaves** HF/5 plants*** Bu/acre
Warrior@2.6 oz
Warrior@ 3.8 oz
Warrior@2.6 oz 2X
Untreated
12.3 c
5.0 c
8.0 c
32.3 b
41.2 c
23.3 c
16.2 c
131.8 a
48.2 a
56.7 a
58.1 a
17.7 b
* Sprayed 3/13; ** on 3/20; *** on 4/6
JVD
Hessian Fly Management Tactics
•
•
•
•
•
•
•
Rotate wheat if possible.
Control volunteer wheat.
Do not use susceptible wheat as cover crops/wildlife plantings.
Conventional tillage (fall and spring).
Plant at recommended times.
Variety selection.
– Plant resistant varieties (if possible).
– Plant susceptible varieties ‘only’ in new fields.
Insecticides use strategies
– Seed treatments
– Lambda cyhalothrin - scouting for late winter suppression.
For Grazing: only oats, rye, ryegrass.
Questions?