We have…..
Carol Jones, PhD, PE, Oklahoma State University
Stored Products Research and Education Center
Missouri Fumigation Training
1
January 10 – 11, 2010
We have…Alternatives
Reasons for alternative methods for
controlling insects…maintaining grain
quality
• Insect resistance
• Customer request (organics, social, marketing)
• Environmental concerns
• Safety
• Governmental regs
Missouri Fumigation Training
2
January 10 – 11, 2010
We have…Alternatives
Methods…
• Aeration
• Ozone
• Heat Treatment
• Ethylene….”Apple Gas”
Missouri Fumigation Training
3
January 10 – 11, 2010
What does aeration do?
• Little insect reproduction occurs below 60F
• Eggs are controlled at 40F
• 40F is tough to do in some areas
• So fumigation is still required but can be
reduced
Carol Jones, PhD.
Stored Product Engineering
Biosystems and Ag. Engr. Dept.
We have…Alternatives
• Little insect reproduction occurs below 60F
• Eggs are controlled at 40F
• 40F is tough to do in some areas
• So fumigation is still required but can be
reduced
Missouri Fumigation Training
5
January 10 – 11, 2010
You have…Alternatives
Missouri Fumigation Training
6
January 10 – 11, 2010
Electrical Generation of Ozone
• Attractive alternative
• Eliminates some of the concerns
– No residues because degradation product is
oxygen
– No transportation of product
– No storage issues
Objectives
• Determine the effectiveness of ozone
fumigation on six stored product pests in a
grain mass of wheat under field conditions
during the month of October, the traditional
time during storage when grain is fumigated
in Oklahoma
Experimental Protocol
• Conducted in October 2007
• Steel grain bins contained
13.6 metric tons of hard red
winter wheat
• One bin treated; one bin
control
• Grain was poor quality
because of extreme wet
conditions at end of growing
season
Ozone Generator
• OZAT Model CFS-3A
• Operated at 30 g/hr
• Produced three targeted
ozone concentrations of
25, 50, and 70 ppm
within the bin
Ozone Introduced into Bin
• Through a 6.4 mm tube from
generator just upstream of
fan into a 10.2 cm pipe
connected to the aeration
fan transition into the
bottom of the bin
• Axial fan moved 0.21 cubic
meters/sec of air/ozone
through grain mass
• Ozone concentration
decreased as it moved
through the grain mass
Insect Sampling Tubes
• Tubes of 10.2 cm diameter
were inserted into bins at
depths corresponding to
targeted ozone levels
• Ozone rose through the
tubes to come in contact
with bags containing insects
• A recirculation system was used to recover
ozone exiting the top of the grain mass and
then injected back into the bottom of the bin
through a closed loop system
• Ozone concentrations monitored every 8 hrs
Insects Evaluated
Rhyzopertha dominica Sitophilus oryzae Tribolium castaneum
Lesser Grain Borer Rice Weevil Red Flour Beetle
Cryptolestes ferrugineus Oryzaephilus surinamensis Plodia interpunctella
Rusty Grain Beetle Sawtoothed Grain Beetle Indianmeal Moth
Insect Samples
• 7.0 x 10.2 cm cotton muslin
tea bags with drawstring
• Bags placed in bins for 1, 2,
3, and 4 days exposure
• Beetle adults and P.
interpunctella larvae were
assessed upon removal
• All grain particles and dust
placed in 226.8 g glass jars
and held at 28°C
• P. interpunctella eggs evaluated after 1 week
and pupae after 2 weeks
• Beetle progeny counted at 2 and 4 weeks
Percent Mortality for P. interpunctella
(Indian Meal Moth)
None Low Medium High None Low Medium High
100 100
Eggs Larvae
80 80
% Mortality
% Mortality
60 60
40 40
20 20
0 0
1-day 2-day 3-day 4-day 1-day 2-day 3-day 4-day
None Low Medium High
100
80
% Mortality
60
40
Pupae
20
0
1-day 2-day 3-day 4-day
Percent Mortality Mean No. Progeny
None Low Medium High None Low Medium High
100 300
80
Eggs 250
Mean Number of Progeny
200
% Mortality
60
150
40
100
20
R. dominica: LGB 50
0 0
1-day 2-day 3-day 4-day 1-day 2-day 3-day 4-day
None Low Medium High None Low Medium High
100 200
80
Mean Number of Progeny
150
% Mortality
60
100
40
S. oryzae: rice weevil
50
20
0 0
1-day 2-day 3-day 4-day 1-day 2-day 3-day 4-day
Percent Mortality Mean No. Progeny
None Low Medium High None Low Medium High
100 125
R.T.
dominica
Eggs castaneum:
80 100
T. dominica
R. castaneum
Red flour beetle
Mean Number of Progeny
% Mortality
60 75
40 50
20 25
0 0
1-day 2-day 3-day 4-day 1-day 2-day 3-day 4-day
None Low Medium High None Low Medium High
100 100
C. ferrugineus: S. oryzae C. ferrugineus S. oryzae
80 80
Mean Number of Progeny
Rusty Grain Beetle
% Mortality
60 60
40 40
20 20
0 0
1-day 2-day 3-day 4-day 1-day 2-day 3-day 4-day
Percent Mortality Mean No. Progeny
O. surinamensis: Sawtoothed grain beetle
None Low Medium High
None Low Medium High
100
400
80
Mean Number of Progeny
300
% Mortality
60
200
40
20 100
0
0
1-day 2-day 3-day 4-day
1-day 2-day 3-day 4-day
We have…Alternatives
• Eggs and larvae of Indianmeal Moth were only
moderately controlled and pupae were the most
sensitive to ozone treatments
• Overall, adult beetle mortality increased with
increasing time of exposure although 100% mortality
was only realized for Rice Weevil and Red Flour
Beetle
• Total suppression of progeny production was only
seen for Red Flour Beetle at the high ozone
concentration
• To obtain total control, either the ozone
concentration should be increased or the time of
exposure increased
Missouri Fumigation Training
January 10 – 11, 2010
Using Heat to
Disinfest
Concrete Silos
Missouri Fumigation Training
January 10 – 11, 2010
Using Heat to Kill Insects
• Attractive alternative
• Eliminates some of the concerns
– No residues
– No transportation of product; heat generated on-site
– No storage issues of dangerous chemicals
– Shorter down-time
Missouri Fumigation Training
January 10 – 11, 2010
Bin Selection for Heating Study
Day 2 Day 1
Control Heat
Day 3
Control
Day 1 Day 3 Day 2
Control Heat Heat
Insects Evaluated
Rhyzopertha dominica Tribolium castaneum
Lesser Grain Borer Red Flour Beetle
Psocids
80
Ambient Air Bin 1-Top
RFB Container
60 LGB Container
Psocid Container
40
20
0
80
Bin 1-33' Down From Top
60
40
Temperature °C
20
0
80
Bin 1-66' Down From Top
60
40
20
0
80
Bin 1-Bottom
60
40
20
0
0900 1100 1300 1500
Percent Survival of RFB Adults
Top 33' down 66' down Bottom
100
75
50
25
0
Heat Control
Percent Survival of LGB Adults
Top 33' down 66' down Bottom
100
75
50
25
0
Heat Control
Progeny Production of RFB
Top 33' down 66' down Bottom
125
100
75
50
25
0
Heat Control
Progeny Production of LGB
Top 33' down 66' down Bottom
350
300
250
200
150
100
50
0
Heat Control
Percent Adult Survival of L. decolor
Top 33' down 66' down Bottom
100
75
50
25
0
Heat Control
Percent Adult Survival of L. corrodens
Top 33' down 66' down Bottom
100
75
50
25
0
Heat Control
Propane Usage
• Average of 76 gallons propane per 99’
silo
• Cost per gallon was $3.00 on May 1, 2008
• Total cost per silo was $228.00
– Equivalent phosphine pellets to treat silo
• 4,000 – 18,000 pellets per silo
• $34.30 - $155.05 based on a cost of $300
per case of 21 flasks of pellets
Missouri Fumigation Training
January 10 – 11, 2010
We have…Alternatives
• Ethylene “apple gas”
• Background and idea
• ANG in Afghanistan
• Early testing
• Killed insects
• Predictions
Missouri Fumigation Training
41
January 10 – 11, 2010
We have…Alternatives
• Manage through IPM
• Identify your insects
• Keep informed of new
methods being tested and
results
Missouri Fumigation Training
42
January 10 – 11, 2010
We have…Alternatives
Carol Jones, PhD, PE, Oklahoma State University
Stored Products Research and Education Center
Missouri Fumigation Training
43
January 10 – 11, 2010