Integrated Pest Management and Fumigation Safety Training. January 24 26, 2017 Kansas State University, Manhattan, Kansas

Transcription

1 Integrated Pest Management and Fumigation Safety Training January 24 26, 2017 Kansas State University, Manhattan, Kansas

2 Phosphine Fumigation of Grain Tom Phillips Professor of Entomology Kansas State University

3 What is a fumigant? A toxic chemical pesticide that is applied to the pest in the gas phase Fumigation represents a pest management hammer, intended to disinfest quickly, when needed Since acting as a gas, it leaves very little or no chemical residue Key uses: commodities, buildings, in transit, quarantine Very dangerous for people; applicators and bystanders must be protected!!!

4 Fumigation should give effective, immediate CONTROL Need to ACT if monitoring detects a problem Fumigation Best for bulk-stored grain in silos, bunkers, sealed warehouses and tarped bag stacks Alternatives include controlled atmospheres, high temperature and cold temperature

5 Variables that Affect Fumigation Success Species of target pest: tolerance level Insects most tolerant life stage: egg, larva, pupa, adult Gas concentration High better than low Exposure time Long better than short Temperature Warm better than cool

6 % Mortality Dose-Mortality Results for Cool Eggs 100 % Egg Mortality at 60 o F (= 16 o C) Dose-Concentration of Fumigant

7 % Mortality Dose-Mortality Results for Warm Eggs 100 % Egg Mortality at 77 o F (=25 o C) Dose-Concentration of Fumigant

8 Common and Available Fumigants Methyl Bromide Phosphine Sulfuryl Fluoride

9 Phosphine: The Primary Fumigant for Grain

10 Metallic Phosphide Salts: Most Common Aluminum Phosphide AlP + 3H 2 O Al(OH) 3 + PH 3 Magnesium Phosphide Mg 3 P 2 + 6H 2 O 3Mg(OH) 2 + 2PH 3

11 Phosphine: Cheap, Easy and Effective Gas is light-weight; penetrates well Tablets/pellets are very economical Effective for most pests Corrosive to electrical fixtures Some insects are resistant,.. and it s spreading!

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14 What is Insecticide Resistance? Resistance occurs when an insect has a genetically controlled trait that allows it to survive an exposure to a toxin that would normally kill others of the same species that lack that trait. Resistance is heritable. It can be selected quickly in a population with each fumigation. Once the proper genes are present each application of phosphine can lead to a resistant population!

15 Evolution of Resistance: One healthy insect is born with a mutation (DNA mistake at cell division) for resistance to a specific pesticide O=susceptible individual O=resistant individual

16 Evolution of Resistance: One healthy insect is born with a mutation (DNA mistake at cell division) for resistance to a specific pesticide Human selection: We apply insecticide to insects with the resistance gene(s); they live and mate with others who may/may not have the genes O=susceptible individual O=resistant individual

17 Evolution of Resistance: One healthy insect is born with a mutation (DNA mistake at cell division) for resistance to a specific pesticide Human selection: We apply insecticide to insects with the resistance gene(s); they live and mate with others who may/may not have the genes Repeated use of the insecticide selects for all resistant survivors in the population!!! O=susceptible individual O=resistant individual

18 Determine number of insects that are phosphine resistant or susceptible at a given location Need a dose that discriminates between susceptible, which die and survivors, which are resistant Test adults from a given population Test adults with the discriminating dose of gas for 20 hour fumigation Assess mortality after 14 days, to allow time for recovery or delayed mortality

19 Controlled Laboratory Fumigation Tests

20 Analyze Gas Concentration with Gas Chromatography

21 Red flour beetles from around North America resistant to phosphine Population State/Prov. 1 City 2 % Resistant 1 AL Uniontown* 31 2 Red Level Ozark 98 4 AR Jonesboro* 20 5 CA Arbuckle 0 6 Davis 0 7 Goshen* 52 8 Princeton* 2 9 Williams 0 10 FL Walnut Hill* GA Nashville Tifton* 0 13 KS Abilene Hudson* 0 15 Junction City 0 16 Kansas City* 0 17 Manhattan Minneapolis MO Excelsior Sprgs 0 20 OK Calumet* 0 21 TX Victoria 2 22 MB Winnipeg 0 23 QC St. Agathe 0 24 SK Saskatoon 0 25 AB Calgary 0

22 Survivorship (%) Found that some places had beetles more resistant than others: Two Bioassays Red Flour Beetle in Kansas: 30 ppm vs 180 ppm Weak Assay Strong Assay Ab1 Ab2 McP MIT MIN RU WA

23 Dose-Mortality plots for populations of Red Flour Beetle with Weak vs Strong Resistance Relative to the Susceptible Strain Susceptible Weak Strong

24 Pop. No. State/Pro City 2 % Res (n) 1 AL Uniontown 89 (90) 2 CA Parlier (1) * 97 (30) 3 CA Parlier (2) 72(90) 4 Williams* 53 (30) 5 Colusa 3 (60) 6 Princeton 71 (31) 7 Biggs 7 (150) 8 FL Belle Glade 87 (90) 9 KS Manhattan (1) 66 (59) 10 Manhattan (2) 77 (150) 11 Manhattan (3) 75 (60) 12 Manhattan (4) 71 (90) 13 Manhattan (5) 78(90) 14 Manhattan (6) 51(50) 15 Manhattan (7) 66(90) 16 Manhattan (8) 48(40) 17 Abilene (1) 93 (30) 18 Abilene (2) 90 (20) 19 Minneapolis 93 (60) 20 Clifton 80 (90) 21 Junction City (1) 57 (30) 22 Junction City (2) 50 (40) 23 Garden City 74 (39) 24 Wamego 54(149) 25 TX Victoria 67 (60) 26 Burleson 87 (90) 27 AB Lethbridge 4 (90) 28 Stirling 14 (90) 29 Bow Island 38(50) 30 SK Carnduff 0 (90) 31 Coronach 19 (90) 32 Weyburn 68(50) 33 Indian Head 62(100) 34 MB Starbuck 0(90) Lesser Grain Borer In North America Kansas pops 9 through 24 Nearly all pops surveyed had some level of resistance = 94%!!!

25 Dose-response plots for six populations of Lesser Grain Borers Weak Resistance Susceptible Strong Resistance

26 Collections for Rusty Grain Beetle, Cryptolestes ferrugineus Killarney Carnduff Prescott Sarnia Junction City Nova Scotia Weslaco Alabama

27 Rusty Grain Beetle %Resistance with FAO Test Nova Scotia-lab 67% Ontario-Prescott 15% Ontario-Sarnia 0% Manitoba-Killarney-a 91% Manitoba-Killarney-b 55% Saskat.-Carnduff 86% Alabama-Coop. 65% KS-Junction City 92% TX-Weslaco 95%

28 Cigarette Beetle

29 Cigarette Beetle Collection Sites VA1 VA2 NC GA KY GA

30 PH 3 Discriminating Dose Results: Cigarette Beetle from Six U.S. Warehouses % Resistance at 50 ppm Discriminating Dose LAB GA FL KY NC VA1 VA2 Populations

31 Can we control resistant beetles with more phosphine held for longer times??? Fumigate jars with all life stages egg, larvae, pupae, adults--like real world! Normal dose = 200 ppm PH 3 for 4 days Dose for resistant beetles = 600 ppm PH 3 for 6 days Count all survivors at the end of the fumigation, and then count daily for 42 days new adults may have been surviving eggs or larvae

32 CORESTA Challenge Results For Cigarette Beetle Populations Low Phosphine High Phosphine Pop Air Control 200 ppm/4 d 600 ppm/6 d GA 31.7 (4.8) A 0.0 (0.0) B 0.0 (0.0) B FL 54.2 (13.8) A 0.2 (0.2) B 0.0 (0.0) B KY (60.0) A (25.8) AB 12.5 (3.4) B NC (16.0) A 83.7 (11.4) B 6.5 (2.7) C VA (50.1) A (25.3) A 7.2 (1.8) B VA (15.9) A 28.2 (6.0) AB 4.8 (1.8) B

33 Can resistance be easily determined? Try a simple knock-down test Tablets placed in canister w/50ml water; get 6000 ppm Dilute with air in knockdown chamber, to be approx ppm Count no. knocked down after given time period, such as 15 min

34 KSU Modified Test: Exactly 3000 ppm in glass tube; record time to Knock Down

35 Phosphine Resistance Management What do we do if we think we have a resistance problem? Should we expect that future use of phosphine for grain bins will simply not work that we will lose phosphine? Should we have some plan in place to prepare? Have other countries faced this same problem?

36 Managing Phosphine Resistance First:.Is there is a problem controlling insects? If resistance is suspected, stop using phosphine! Use a totally different fumigant or good grain protectant! ***New mode of action; must kill all PH3-resistant pests! PH 3 can be resumed only when problem is managed. Practice good stored grain IPM: prevention, sanitation, monitoring, targeted action.

37 ProFume Gas called Sulfuryl Fluoride (same as Vikane for termites) Registered for stored grain, flour mills, nuts, dried fruits, etc. Non-corrosive Alternative for PH 3 Resistance: totally different mode of action!

38 Alternatives to Current Fumigants Residual chemicals sprayed on grain Extreme Temperatures: Heat and Cold Below freezing or Near 100 F Controlled or modified atmospheric gases Reduce Oxygen, or increase CO 2

39 Modified Atmosphere with Cocoon: Low Oxygen and High CO 2

40 Thank You Very Much! Any questions? Feel free to contact me with any questions or comments: Tom Phillips Phone: Thanks for attending!!!

41 This presentation was made possible by a grant from The Technical and Operational Performance Support (TOPS) Program. The TOPS Micro Grants Program is made possible by the generous support and contribution of the American people through the U.S. Agency for International Development (USAID). The contents of the materials produced through the Micro Grants do not necessarily reflect the views of TOPS, USAID, or the U.S. Government.