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

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 KSU Hal Ross Flour Mill on each floor Building Layout 1-5/ 1-6 4 1 1-3 2 3 5 6 1-4 1-1 1-2

Pressurization Test • Flow rate VS Pressure – Good seal  Lower flow rate at any given pressure Worse seal 3 Flow rate (m3/ s) 2 Better seal 1 0 0 20 40 60 80 100 Pressure (Pa)

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 3 Flow rate (m3/ s) 2 M B1 SF2 M B3 SF4 1 0 0 20 40 60 80 100 120 140 Pressure (Pa)

Gas Concentration: MB1 10.2hr HLT 16.4hr HLT Avg spd 111hr HLT Avg spd = 7.12 Avg spd = 3.52 = 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

Temperatures 35 35 30 30 Temperature (C) Temperature (C) Flr 1 Flr 1 25 25 Flr 2 Flr 2 Flr 3 Flr 3 20 20 Flr 4 Flr 4 MB1 SF2 Flr 5 Flr 5 15 15 Outside Outside 10 10 0 5 10 15 20 25 0 5 10 15 20 25 Elapsed time (hr) Elapsed time (hr) 35 35 30 30 Temperature (C) Temperature (C) Flr 1 Flr 1 25 25 Flr 2 Flr 2 Flr 3 Flr 3 20 20 Flr 4 Flr 4 Flr 5 Flr 5 MB3 SF4 15 15 Outside Outside 10 10 0 5 10 15 20 25 0 5 10 15 20 25 Elapsed time (hr) Elapsed time (hr)

Relative Humidity 100 100 80 80 Flr 1 Flr 1 60 60 RH (%) RH (%) Flr 2 Flr 2 Flr 3 Flr 3 40 40 Flr 4 Flr 4 Flr 5 Flr 5 MB1 SF2 20 20 Outside Outside 0 0 0 5 10 15 20 25 0 5 10 15 20 25 Elapsed time (hr) Elapsed time (hr) 100 100 80 80 Flr 1 Flr 1 60 60 RH (%) RH (%) Flr 2 Flr 2 Flr 3 Flr 3 40 40 Flr 4 Flr 4 Flr 5 Flr 5 20 20 Outside Outside MB3 SF4 0 0 0 5 10 15 20 25 0 5 10 15 20 25 Elapsed time (hr) Elapsed time (hr)

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 Small Large Data Eggs Pupae Adults Larvae Larvae Logger

Bioassay placement 25 boxes in the mill 1 control box in lab

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 statistics 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 1 1.20 0.02 0.90 Depth Error 4 65.35 Large larvae Treatment 1 0.09 5.14 0.09 Depth 1 0.02 1.08 0.36 Treatment x 1 0.01 0.40 0.56 Depth Error 4 0.02

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. 100 90 80 70 Mortality (%) 60 50 40 30 20 10 0 1000 1050 1100 1150 1200 1250 1300 Ct Product (g-h/m 3 )

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. 100 90 80 70 Mortality (%) 60 50 40 30 20 10 0 1000 1050 1100 1150 1200 1250 1300 Ct Product (g-h/m 3 )

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. 100 99 98 Mortality (%) 97 96 95 94 93 600 700 800 900 1000 1100 1200 Ct Product (g-h/m 3 )

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 orkshop_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 9626 Gas m 3 heater Propane tank High-temp. ductwork http://www.youtube.com/view_play_list?p=070733D50D9989 8D

RESULTS

Mean (± SE) temperatures in box bioassays ( n = 2) Floor Flour dust 2 cm flour Time to Time M aximum Time to Time M aximum 50 o C 50 o C above temperature above temperature 50 o C ( o C) 50 o C ( o C) (h) (h) (h) (h) 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 99.2 ± 0.4 98.0 ± 2.0 First Eggs 99.0 ± 1.0 84.4 ± 0.4 Y oung larvae 89.8 ± 10.2 83.4 ± 9.6 Old larvae 89.8 ± 10.2 90.8 ± 7.8 Pupae 90.0 ± 10.0 50.6 ± 10.2 Adults 99.8 ± 0.2 Second Eggs 100.0 99.4 ± 0.6 Y oung larvae 100.0 Old larvae 100.0 100.0 Pupae 100.0 100.0 Adults 100.0 100.0 Third Eggs 100.0 100.0 99.4 ± 0.6 99.8 ± 0.2 Y oung larvae 99.6 ± 0.4 Old larvae 100.0 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 oung larvae 100.0 100.0 99.8 ± 0.2 Old larvae 100.0 Pupae 100.0 100.0 Adults 100.0 100.0 Fifth Eggs 100.0 100.0 99.8 ± 0.2 99.4 ± 0.6 Y oung larvae 99.2 ± 0.4 99.5 ± 0.5 Old larvae Pupae 100.0 100.0 Adults 100.0 100.0

Box bioassays: ANOVA statistics Source of df M ean square F -value P -value variation 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 16 53.911500 2.36 0.0108 pth Error 50 22.890000

Correlation among variables and mortality (%) Variables Adults Pupae Old larvae Young larvae Eggs Time to 50 o C -0.61 -0.76 -0.74 -0.52 -0.69 (0.060) (0.011) (0.014) (0.124) (0.027) Time above 50 o C 0.68 0.78 0.78 0.59 0.75 (0.032) (0.008) (0.007) (0.073) (0.013) M ax. temp.( o C) 0.74 0.85 0.86 0.66 0.81 (0.014) (0.002) (0.001) (0.039) (0.004) Values in bracket represent P-values for H o : 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 15 g  1.0 cm 38 g  3.0 cm 109 g  6.0 cm 388 g  10.0cm 937 g 1645 g – Locations  First & Third floors  One location