EFFECTIVENESS OF METHYL BROMIDE, SULFURYL FLUORIDE, AND HEAT AGAINST - - PowerPoint PPT Presentation

EFFECTIVENESS OF METHYL BROMIDE, SULFURYL FLUORIDE, AND HEAT AGAINST RED FLOUR BEETLE LIFE STAGES

Bhadriraju Subramanyam (Subi), Dirk E. Maier, Michelle Hartzer, and Watcharapol Chayaprasert Grain Science and Industry, Kansas State University, KS James F. Campbell and Paul W. Flinn USDA-CGAHR, Manhattan, KS

Treatments, 2009

Spring Fall

Methyl Bromide: August 11-12 Sulfuryl Fluoride: August 19-20 Heat Treatment: August 25-26 Methyl Bromide: May 6-7 Heat Treatment: May 13-14 Sulfuryl Fluoride: May 27-28

Treatments

• May treatment

– MB – 400 lbs – SF – 1250 lbs – Heat - Propane

• August

– MB – 350 lbs – SF – 1125 lbs – Heat - Propane

Environmental variables measured

• Pressurization test
• Weather station

(temperature, RH, wind, solar radiation, barometric pressure)

• Temp/RH logger (one point on each floor)

Gas monitoring

• Gas concentrations continuously

monitored at 6 locations evenly distributed

• n each floor

KSU Hal Ross Flour Mill Building Layout

6 1 2 3 4 5

1-1 1-2 1-3 1-4 1-5/ 1-6

1 2 3 20 40 60 80 100 Flow rate (m3/ s) Pressure (Pa)

Pressurization Test

• Flow rate VS Pressure

– Good seal  Lower flow rate at any given pressure

Better seal Worse seal

1 2 3 20 40 60 80 100 120 140 Flow rate (m3/ s) Pressure (Pa) M B1 SF2 M B3 SF4

Pressurization Test

• Sealing quality of MB1, SF2 and MB3

fumigations was identical

• Pressure test result of SF4 experiment was

adversely affected by strong outdoor wind  Assuming best sealing quality of SF4

experiment, sealing quality of all fumigations was the same

Gas Concentration: MB1

16.4hr HLT

Avg spd = 3.52

10.2hr HLT

Avg spd = 7.12

111hr HLT

Avg spd = 1.65

Gas Concentration: SF2

19.7hr HLT

Avg spd = 3.67

Gas Concentration: MB3

26hr HLT

Avg spd = 2.16

Gas Concentration: SF4

9.9hr HLT

Avg spd = 6.9

26.1hr HLT

Avg spd = 3.0

Barometric Pressure

10 15 20 25 30 35 5 10 15 20 25 Temperature (C) Elapsed time (hr) Flr 1 Flr 2 Flr 3 Flr 4 Flr 5 Outside 10 15 20 25 30 35 5 10 15 20 25 Temperature (C) Elapsed time (hr) Flr 1 Flr 2 Flr 3 Flr 4 Flr 5 Outside 10 15 20 25 30 35 5 10 15 20 25 Temperature (C) Elapsed time (hr) Flr 1 Flr 2 Flr 3 Flr 4 Flr 5 Outside 10 15 20 25 30 35 5 10 15 20 25 Temperature (C) Elapsed time (hr) Flr 1 Flr 2 Flr 3 Flr 4 Flr 5 Outside

Temperatures

MB1 SF2 SF4 MB3

Relative Humidity

20 40 60 80 100 5 10 15 20 25 RH (%) Elapsed time (hr) Flr 1 Flr 2 Flr 3 Flr 4 Flr 5 Outside 20 40 60 80 100 5 10 15 20 25 RH (%) Elapsed time (hr) Flr 1 Flr 2 Flr 3 Flr 4 Flr 5 Outside 20 40 60 80 100 5 10 15 20 25 RH (%) Elapsed time (hr) Flr 1 Flr 2 Flr 3 Flr 4 Flr 5 Outside 20 40 60 80 100 5 10 15 20 25 RH (%) Elapsed time (hr) Flr 1 Flr 2 Flr 3 Flr 4 Flr 5 Outside

MB1 SF2 SF4 MB3

Solar Radiation

Summary of observations

• First head-to-head comparison between MB and

SF under nearly identical conditions in the same facility

• SF and MB showed similar gas dynamics

(i.e., gas distribution and leakage characteristics)

– Inside gas distributions were dominated by circulation fans – Leakage rates were influenced by environmental conditions – For these particular experiments, wind was the dominating factor

• Sealing effectiveness can be determined by

pressurization testing ahead of a fumigation

– It cannot perfectly predict HLT – It can differentiate a "well" vs "poorly" sealed facility

Insect bioassays

The whole bioassay

Eggs Small Larvae Data Logger Large Larvae Pupae Adults

25 boxes in the mill 1 control box in lab

Bioassay placement

Results

Mean mortality by treatment, stage, and flour depth

Treatment Insect Stage Flour Depth Mean±SE Mortality (%) MB Egg 2cm 100.00 Egg Dusting 100.00 Small Larvae 2cm 100.00 Small Larvae Dusting 100.00 Large larvae 2cm 99.70±0.16 Large larvae Dusting 99.96±0.08 Pupae 2cm 100.00 Pupae Dusting 100.00 Adult 2cm 100.00 Adult Dusting 100.00

Mean mortality by treatment, stage, and flour depth

Treatment Insect Stage Flour Depth Mean±SE Mortality (%) SF Egg 2cm 91.00±9.00 Egg Dusting 92.55±7.05 Small Larvae 2cm 100.00 Small Larvae Dusting 100.00 Large larvae 2cm 99.96±0.04 Large larvae Dusting 100 Pupae 2cm 100 Pupae Dusting 100 Adult 2cm 100 Adult Dusting 100

Stage Source df Mean square F-value P-value Egg Treatment 1 135.30 2.07 0.22 Depth 1 1.20 0.02 0.90 Treatment x Depth 1 1.20 0.02 0.90 Error 4 65.35 Large larvae Treatment 1 0.09 5.14 0.09 Depth 1 0.02 1.08 0.36 Treatment x Depth 1 0.01 0.40 0.56 Error 4 0.02

Stage statistics

10 20 30 40 50 60 70 80 90 100 1000 1050 1100 1150 1200 1250 1300 Mortality (%) Ct Product (g-h/m3)

Scatter plot showing variation in egg mortality in compartments with flour dusting as a function of the concentration x time (Ct) product during May 6- 7, 2009 fumigation with sulfuryl fluoride.

10 20 30 40 50 60 70 80 90 100 1000 1050 1100 1150 1200 1250 1300 Mortality (%) Ct Product (g-h/m3)

Scatter plot showing variation in egg mortality in compartments with 2 cm deep flour as a function of the concentration x time (Ct) product during May 6-7, 2009 fumigation with sulfuryl fluoride.

93 94 95 96 97 98 99 100 600 700 800 900 1000 1100 1200 Mortality (%) Ct Product (g-h/m3)

Scatter plot showing variation in egg mortality in compartments with flour dusting as a function of the concentration x time (Ct) product during August 19-20, 2009 fumigation with sulfuryl fluoride.

Workshops

• May 13-15, 2009

– Hands-on workshop on heat treatment – Weblink: http://www.ksre.ksu.edu/grsc_subi/Heat_Worksho p_09_slides.htm

• August 19-21, 2009

– Hands-on workshop on sulfuryl fluoride fumigation – Weblink: http://www.ksre.ksu.edu/grsc_subi/Conference/W

• rkshop_SF_2009/index_old.htm

Efficacy of structural heat treatments against red flour beetle life stages

• In bioassay boxes
• In PVC rings

KSU Hal Ross flour mill: Heat treatment equipment

http://www.youtube.com/view_play_list?p=070733D50D9989 8D 9626 m3 Gas heater Propane tank High-temp. ductwork

RESULTS

Mean (± SE) temperatures in box bioassays (n = 2)

Floor Flour dust 2 cm flour Time to 50oC (h) Time above 50oC (h) M aximum temperature (oC) Time to 50oC (h) Time above 50oC (h) M aximum temperature (oC) First 17.2 ± 1.5 6.9 ± 1.5 52.0 ± 1.4 17.2 ± 1.6 6.0 ± 0.8 50.7± 1.4 Second 10.4 ± 2.6 13.6 ± 2.6 59.6 ± 2.7 13.5 ± 3.4 10.6 ± 3.4 57.7 ± 2.9 Third 10.5 ± 0.5 13.5 ± 0.5 61.4 ± 0.7 12.2 ± 0.4 11.8 ± 0.4 60.1 ± 1.3 Fourth 12.6 ± 2.2 11.5 ± 2.2 58.9 ± 1.2 15.4 ± 2.7 8.6 ± 2.7 56.2 ± 1.7 Fifth 12.0 ± 1.9 12.0 ± 1.9 57.7 ± 1.1 14.9 ± 2.3 9.1 ± 2.3 55.4 ± 1.4

Mean (± SE) mortality (%) among mill floors (n = 2)

Floor Life stage Flour dust 2 cm flour First Eggs 99.2 ± 0.4 98.0 ± 2.0 Y

• ung larvae

99.0 ± 1.0 84.4 ± 0.4 Old larvae 89.8 ± 10.2 83.4 ± 9.6 Pupae 89.8 ± 10.2 90.8 ± 7.8 Adults 90.0 ± 10.0 50.6 ± 10.2 Second Eggs 100.0 99.8 ± 0.2 Y

• ung larvae

99.4 ± 0.6 100.0 Old larvae 100.0 100.0 Pupae 100.0 100.0 Adults 100.0 100.0 Third Eggs 100.0 100.0 Y

• ung larvae

99.4 ± 0.6 99.8 ± 0.2 Old larvae 100.0 99.6 ± 0.4 Pupae 100.0 100.0 Adults 100.0 100.0

Floor Life stage Flour dust 2 cm flour Fourth Eggs 100.0 100.0 Y

• ung larvae

100.0 100.0 Old larvae 100.0 99.8 ± 0.2 Pupae 100.0 100.0 Adults 100.0 100.0 Fifth Eggs 100.0 100.0 Y

• ung larvae

99.8 ± 0.2 99.4 ± 0.6 Old larvae 99.2 ± 0.4 99.5 ± 0.5 Pupae 100.0 100.0 Adults 100.0 100.0

Box bioassays: ANOVA statistics

Source of variation df M ean square F-value P-value Stage 4 87.35760 3.82 0.0088 Floor 4 614.39160 26.84 <0.00001 Depth 1 146.41000 6.40 0.0146 Stage* Floor 16 89.637100 3.92 0.0001 Stage* Depth 4 53.208000 2.32 0.0692 Floor* Depth 4 147.02600 6.42 0.0003 Stage* Floor* De pth 16 53.911500 2.36 0.0108 Error 50 22.890000

Correlation among variables and mortality (%)

Variables Adults Pupae Old larvae Young larvae Eggs Time to 50oC

• 0.61

(0.060)

• 0.76

(0.011)

• 0.74

(0.014)

• 0.52

(0.124)

• 0.69

(0.027) Time above 50oC 0.68 (0.032) 0.78 (0.008) 0.78 (0.007) 0.59 (0.073) 0.75 (0.013) M ax. temp.(oC) 0.74 (0.014) 0.85 (0.002) 0.86 (0.001) 0.66 (0.039) 0.81 (0.004)

Values in bracket represent P-values for Ho: Rho = 0 (Pearson’s correlation coefficient).

Effect of sanitation on insect kill

• Ring bioassays

– Life Stages

• Eggs
• Adults

– Flour depths

• 0.1 cm
• 0.2 cm
• 1.0 cm
• 3.0 cm
• 6.0 cm
• 10.0cm

– Locations

• First & Third floors
• One location

15 g 38 g 109 g 388 g 937 g 1645 g

Flour depth (cm) First floor Third floor Control Time to 50oC (h) Time above 50oC (h) Max. temp. (oC) Mortality (%) Time to 50oC (h) Time above 50oC (h) Max. temp. (oC) Mortality (%) Max. temp. (oC) Mortality (%) 0.1 13.3 10.8 55.5 100.0 15.2 8.8 58.0 100.0 29.0 10.0 0.2 22.0 2.1 50.5 100.0 15.6 8.4 58.0 100.0 29.5 * 1.0

• 46.5

91.0 14.7 9.3 59.0 100.0 29.5 * 3.0

• 45.0

92.0 14.4 9.6 59.5 100.0 29.5 17.0 6.0

• 45.0

99.0 15.4 8.6 57.5 100.0 29.5 * 10.0

• 44.0

77.0 14.8 9.2 58.5 100.0 29.0 26.0

Eggs mortality (%) after 24 h, August 25-26, 2009

Flour depth (cm) First Floor Third Floor Control Time to 50oC (h) Time above 50oC (h) Max. temp. (oC) Mortality (%) Time to 50oC (h) Time above 50oC (h) Max. temp. (oC) Mortality (%) Max. temp. (oC) Mortality (%) 0.1

• 48.5

89.0 15.0 9.0 58.0 100.0 29.0 0.0 0.2

• 47.0

20.0 15.8 8.3 57.5 100.0 29.0 0.0 1.0

• 46.0

5.0 15.9 8.1 58.0 100.0 29.5 1.0 3.0

• 44.0

2.0 16.4 7.7 57.5 100.0 30.0 0.0 6.0

• 42.5

2.0 16.7 7.3 56.5 100.0 29.0 0.0 10.0

• 42.5

9.0 16.3 7.7 57.0 100.0 29.5 0.0

Adult mortality (%) after 24 h, August 25-26, 2009

Ring bioassays: Summary

• On the third floor rate of temp. increase from ambient to 50ºC ranged

from 1.49 to 1.62 ºC/h for rings with eggs and 1.41 to 1.60 ºC/h for rings with adults

• The temperatures ramped to 50ºC within the rings at 24 hours only
• n the third floor and few rings on the first floor.
• Poor sanitation will confer insect survival only if temperatures do not

reach 50oC.

• Less than 100% mortality in ring bioassays can be attributed to slow

heating rates and temperatures not reaching 50oC or lethal temperatures.

Overall conclusions

• MB was the most effective product.
• Effectiveness of SF against eggs was poor at

temperatures below 80oF.

• Heat treatment was effective against all life stages of the

red flour beetle except on the first floor, where temperatures did not reach 50oC.

• Last set fo treatments will occur in May 2010.
• Economic analysis of treatments will be done after the

May 2010 treatments.

Acknowledgments

• This research was funded by a grant (2008) from the

USDA/CSREES Methyl Bromide Transitions Program under agreement number 2008-51102-04583

• Temp-Air, Burnsville, MN conducted the heat treatments
• IFC, Olathe, KS, and Presto-X, Omaha, NE, did the mill

fumigations

Thank You