Effectiveness of Aerosols for Insect Control in the Food Industry

Transcription

1 Effectiveness of Aerosols for Insect Control in the Food Industry Frank Arthur USDA-ARS-CGHAR Manhattan, KS 66502

2 During This Conference You have heard presentations on aspects of fumigation with MB and SF You will hear talks on control Where do aerosols fit treatments? insect monitoring, in with whole-plant

3 Aerosols/Fogs/ /ULV Defined Aerosols (Fogs, ULVs) are liquid formulations, atomized and applied through a nozzle Kill exposed flying or crawling insects They do not penetratee food material, packaging, equipment, etc. (Not Fumigants) Aerosols and fumigants sometimes are used interchangeably

4 Red flour beetle (RFB) Tribolium castaneum

5 Confused flour beetle (CFB) Tribolium confusum

6 Why Thesee Species? Common pests of stored food CFB adults do not fly, RFB adults fly at ~80-85 F, minimizes escape into facility These species generally harder to kill than other stored product beetles Can do tests with larvae as well

7 Field Trials with Aerosols Questions regarding dispersion of aerosols, efficacy, and residual persistence Hard to evaluate aerosols in lab tests I will discuss results from several different field projects

8 Field Trial #1 Active commercial food storage facility Tests conducted in one room, approximately 225 L x 75 W x 35 H (600,000 ft 3 )

9 Partial View of the Test Room

10 ULV System An installed ULV system on a timer, dispensed particle size about 15 microns Insecticide was a mixture of 1% pyrethrin+ synergists, applications were made according to label specifications for this formulation Trials conducted on 5 different dates with the red flour beetle and the confused flour beetle

11 Methods of Exposure 15 positions on the floor of the testing area (5 on side walls, 5 in center, all front to back) Ten adult CFB and RFB exposed in dishes (lined filter paper); w or w/o 250 mg of flour; 4-week old larvae and pupae with flour Dishes exposed to ULV fog for 2 hours, controls were held in a separate room

12 Position of Dishes, sets 1-5 and between wall and pallets, X is nozzles X X NORTH

13 Fog distribution from 2 nozzles suspended from the ceiling

14 RFB Adults-No Flour Percentage Response Survival KD Mortality 7-days 14-days Time After Exposure

15 CFB Adults-No Flour Percentage Response Survival KD Mortality 0 7-days 14-days Time After Exposure

16 Adult Survival: Flour vs No Flour % Survival-7 days No Flour Flour 0 CFB RFB Beetlee Species

17 Results Presence of the food source increased adult survival after exposure to aerosol Similar to results from studies with contact insecticides Emphasizes importance of sanitation However, you can t completely eliminate all food sources in a mill or warehouse

18 Field Trial #2 Pyrethrin-pyriproxyfenn (IGR NyGuard) Concrete arenas placed in open and closed positions at the floor and 12-ft high 4-week old larvae of red and confused flour beetles were exposed (with flour) Residual tests every 2 weeks for 10 weeks

19 Concrete Exposure Arena

20 Results No adult emergence of either species at any of the exposure positions (open or closed on the floor and at 12 ft. high) Residues were active for up to 10 weeks with complete control of the 4-week old larvae, none made it to the adult stage

21 Field Trial #2A Same insecticides and exposure conditions, residual tests done at 0-10 weeks Ten mixed-sex adult red flour beetles exposed for one week with 300 mg of flour Adults removed after 1 week, flour held for 6 weeks at 80 F-60% RH (standard rearing)

22 Results No differences with exposure positions (open or closed on the floor and at 12 ft. high) No differences with weeks, residues were again active for 10 weeks

23 More Results Number of progeny adults in untreated controls averaged 26.0 ± 1.2 Number of progeny adults in treatments averaged 0.07 ± 0.03, even with an extra 4 week holding period 2,732 total adults in the untreated controls, only 8 in the treatments!

24 Control Arena

25 Arena Exposed to Aerosol

26 Field Trial #3 Active flour mill using either 1% pyrethrin + Diacon or 3% pyrethrin + Diacon Test involved 4 separate replications of each concentration At each replication, two sets of 54 Petri dishes with 6 grams of flour each were exposed in open areaa of one floor of the mill Aerosol applied according to label

27 Bioassays The two sets of 54 exposed dishes with the flour brought back to lab and held in freezer Every two weeks from 0-16 weeks post- each set removed treatment one dish from from freezer-residual test of aerosol deposit 3 grams from each dish divided into 6 dishes containing 0.5 grams

28 Bioassays 2 At each bioassay, 10 4-week-old red flour beetle larvae were put in each dish (60 total) 10 4-week-old confused flour beetle larvae put in each dish (60 total) Untreated controls also set up for each bioassay on flour not exposed to the aerosols

29 Untreated Controls Virtually 100% emergence of normal adults in the untreated controls for both species Few or no morphological defects in immatures or adults No differences at any of the bioassay times Controls excluded from further analysis

30 Results 1 Emergence of adult red flour beetles was 0 to 1.5% for both the 1% and 3% pyrethrin + Diacon, at all bioassays, for 16 weeks Confused flour beetlee was much more tolerant to the aerosol mixture Results similar to other studies with IGRs Reduced emergence of confused flour beetle adults at the 3% pyrethrin-unexpected

31 Confused Flour Beetle % Adult Emergence % PY+D 3% PY+D * * * * * Weeks Post-Treatment

32 Results Seemed to be an additive effect of the two insecticides Confused flour beetlee more tolerant species Excellent residual efficacy of the aerosol Additional research on aerosol deposition on different packaging materials

33 Results 2-Morphological Defects Generally showed up earlier in the red flour beetle compared to the confused For the red flour beetle, most defects occurred in the larval stage For confused flour beetle, most defects occurred in the pupal and adult stages Greater effects with the 3% pyrethrin + Diacon compared to the 1% - unexpected

34 Both Species 40 % Dead Larvae % PY+D 3% PY+D 0 C FB R FB

35 Both Species 50 % Arrested Larvae % PY+D 3% PY+D 0 C FB R FB

36 Both Species % Arrested Larvae/Pupae % PY+D 3% PY+D CFB RFB

37 Both Species 3 0 % Dead Pupae % P Y + D 3% P Y + D 0 C F B R F B

38 Summary Aerosol insecticides can be effectively used in commercial facilities They can replace but probably not eliminate all whole-plant treatments We need much more research in actual field sites and commercial facilities

39 For More Information Phone: