Potential of Vapormate TM for control of arthropod pests on citrus Aromashield.com Beth Mitcham and Veronique Bikoba Department of Plant Sciences University of California, Davis September 4 th 2014 Vapormate update Liquid mixture of ethyl formate and CO 2 Provided and stored in compressed pressurized cylinders by the Linde Group Registered in Australia, New Zealand, Philippines, South Korea, Indonesia, Israel, and Tunisia. Pending in Malaysia, Russia, South Africa, and the US Registration in the US is being pursued by the Linde Corporation and is projected for end of 2014 1
Vapormate Effectiveness Demonstrated on: Aphids Bean thrips Black widow spiders California red scales Citrus Flat mites cms.cnr.edu.bt News.softpedia.com Grape mealy bugs Light Brown apple moth Omnivorous leaf roller Pacific spider mites Two spotted spider mites Omnivorous leafroller Western flower thrips Asian citrus psyllid (ACP) ACP LBAM 2
Effect of Vapormate on various citrus pests Various doses of ethyl formate tested 0 61.96g/m³ (0 2%) Arthropods kept in vented vials during treatment except for bean thrips and California red scale which were on fruit Fumigation in 1 cubic foot chamber Mortality evaluation 24h after fumigation Controls kept separately from fumigated specimens LDs or LTs calculated for some of the pests Citrus Flat Mites Minutes required to achieve mortality level following Vapormate fumigation at 59 F LTs 31.0g/m³ (1% EF) (n=4293) 62.0g/m³ (2% EF)(n=8134) LT50 50.2 (48.7 51.5) 18.4 (17.9 18.8) LT90 62.9 (61.3 65.1) 22.6 (21.92 23.4) LT99 75.6 (71.9 81.0) 26.7 (25.5 28.4) LTP9 101.3 (92.4 115.6) 34.9 (32.3 38.9) 3
Asian Citrus Psyllid Adults Trials conducted at the Contained Research Facility (CRF) at UC Davis Specimens from ACP colony maintained by CRF staff 3 temps tested: 41 F, 50 F, and 59 F 1 hour fumigation Mortality assessed 24 hours after fumigation Asian Citrus Psyllid Adults Ethyl formate dose in g/m³ for 1 h required to achieve various mortality levels at 3 different temperatures LDs 41 F (n=3821) 50 F (n=3013) 59 F (n=6684) LD50 1.5 (1.5 1.6) 2.0 (1.9 2.1) 2.4 (2.34 2.4) LD90 2.3 (2.2 2.4) 2.5 (2.4 2.6) 2.8 (2.7 2.9) LD99 3.2 (3.0 3.4) 2.9 (2.7 3.1) 3.2 (3.1 3.4) LDP9 5.4 (4.9 6.0) 3.9 (3.6 4.3) 4.0 (3.8 4.4) 4
Bean Thrips Ethyl formate dose in g/m³ required to achieve various mortality levels at 3 different temperatures LDs 41 F 50 F 59 F LD50 2.2 (2.0 2.4) 2.7 (2.3 3.0) 2.6 (2.3 2.8) LD90 3.3 (3.0 3.7) 4.4 (4.0 5.2) 3.9 (3.7 4.2) LD99 4.4 (3.9 5.7) 6.5 (5.4 9.3) 5.4 (4.9 6.4) LDP9 7.3 (5.7 11.7) 12.0 (8.6 24.2) 9.3 (7.6 13.0) Bean thrips inside the navel of oranges during 1 hour fumigation Western Flower Thrips & California Red Scale Ethyl formate dose in g/m³ required to achieve various mortality levels after 1 hour fumigation at 20 C (68 F) LDs Western Flower Thrips California Red Scale LD95 4.3 (4.0 4.6) 12.8 (11.8 14.1) LD99 5.0 (4.6 5.6) 17.6 (15.7 20.2) LD99.9 6.9 25.0 LDP9 7.4 (6.0 8.8) 38.1 (31.4 48.8) Pupin et al. 2013 Journal Economic Entomology 5
Pacific spider mites Life stage tested LDP9 (95% limits) Eggs 9,230 1.91 (1.67 2.39) Protonymph 5,636 1.95 (1.73 2.28) Deutonymph 4,847 2.44 (2.01 3.29) Adults 10,414 3.45 (2.99 4.26) 1 hour fumigation at 75.2F Fuller Rose Beetle Adults field collected by Spencer Walse s lab group Adults lay eggs on folded waxed paper (use 7 14 d old) Waxed paper with eggs soaked in 2% potassium sorbate to prevent/reduce mold, air dried Wax paper with eggs treated in vented vials in 1 cubic foot chamber 6
Fuller Rose Beetle Adults collected by Sara J. Scott, Assistant of Dr. Grafton Cardwell Adults put on oranges as shown with food Eggs are laid under calyx Adults and food removed after 3 5 days Citrus kept for 6 9days before fumigation Ethyl formate effect on Fuller rose beetle eggs Ethyl formate g/m³ (%) Time (hour) # tested mean % mortality Standard deviation 1531 8.3 5.49 62.0 (2) 1 138 19.57 17.41 62.0 (2) 2 180 40 14.86 62.0 (2) 3 868 80.07 9.39 62.0 (2) 4 1126 85.79 5.89 62.0 (2) 5 924 97.29 4.49 62.0 (2) 6 1030 97.67 2.13 93.0 (3) 1 198 40.40 6.12 93.0 (3) 2 124 54.03 16.35 124.0 (4) 1 138 60.87 36.11 124.0 (4) 2 182 91.21 9.26 7
Tolerance of Navel oranges to higher Vapormate doses or longer fumigation times before storage Ethyl formate doses tested for 2 4 hours at 59 F 93g/m³ (3% ) 108g/m³ (3.5%) 124g/m³ (4%) Low dose 62g/m³ (2%) tested for 8 hours at 59 F Methods Fruit from a Sunkist Grower s Association packinghouse Fruit stored at 41 F awaiting fumigation Waxed and export grade navel oranges, size 88, packed in export boxes All fumigations done in 1,038L forced air fumigation chamber with fan speed at 1000rpm 8
Fruit handling after fumigation for high dose tests 20 fruit transferred to 68 F to monitor damage development following fumigation to help determine subsequent fumigation doses 20 fruit transferred to 59 F for 5 days then to 68 F for 2 days before visual peel damage assessment The remaining fumigated fruit divided into 2 groups 41 F for 2 weeks 37 F for 2 weeks Control fruit handled in the same manner Fruit handling for 8 hour fumigation tests The fumigated fruit were divided into 3 groups The first group was transferred to 59 F for 5 days then to 68 F for 2 days followed by final peel damage assessment The remaining fumigated fruit divided into 2 groups: 41 F for 2 weeks 37 F for 2 weeks The second set of fruit transferred to 37 F for 2 weeks followed by Vapormate fumigation The 3 rd set transferred to 41 F for an extra 2 weeks followed by Vapormate fumigation Control fruit handled in the same manner 9
4% EF 2h 4% EF 4h 3.5% EF 4h Control 5d at 59F + 2 d @ 68F Control 2% EF 8 h 2% (62 g/m3) Ethyl Formate is Maximum Dose Tolerated. Can tolerate 8h + 10
Can a surfactant or an acid pre treatment enhance the efficacy of Vapormate on Fuller rose beetle eggs? Two Minute Dip in 1% Surfactant (360E FG; Ivanhoe Ind.) % 360E FG % EF Time (h) Cold Storage Temp Weeks Cold # tested Mean % mortality 488 6.30 4.27 1 789 30.28 7.04 2 6 1030 97.67 2.13 1 2 6 41 F 3 765 99.02 1.29 SD Two Minute Dip in 20% Citric Acid Before Fumigation % citric acid % EF Time (h) # Tested mean % mortality Standard deviation 341 13.49 1.79 20 1450 85.07 5.94 2 6 1030 97.67 2.13 20 2 5 1318 100 0 20 2 6 1325 99.68 0.51 11
Two Minute Dip in 1% Quinic Acid Followed by Fumigation Quinic acid is obtained from cinchona bark, coffee bark and beans, and other plant products. It is synthetically produced by hydrolysis of chlorogenic acid Quinic acid (%) % ethyl formate time # Tested mean % mortality SD 231 5.25 5.21 1 1415 75.13 18.18 2 3 868 80.07 9.39 1 2 2 2051 99.37 0.29 1 2 3 2305 99.62 0.41 Ethyl formate efficacy with and without pre treatments Pre trt Dip (min) 62.0g/m³ (2%) EF Time (h) # tested Mean mortality Standard deviation 2591 8.97 3.11 yes 6 1030 97.67 2.13 1% 360E 2 yes 6 765 99.02 1.29 FG 20% citric 2 yes 6 1325 99.68 0.51 acid 1% quinic acid 2 yes 3 2305 99.62 0.41 12
What next? When Fuller rose beetle eggs become available again, we will: Test Citric acid + 2% (30.98g/m³) ethyl formate for 7 8 hour Test Quinic acid + 2% (30.98g/m³) ethyl formate for 4 8 hour Develop the mortality curve for Fuller rose beetle eggs Calculate the LDs (50,90,99,P9) Test the LDP9 on navel oranges if time longer than 8 hours Confirm mortality in forced air chamber @59F Dosing with Vapormate To achieve 62.0 g/m 3 (2%) ethyl formate: 25kg cylinder can treat 66m 3 (2,331 ft 3 ) If Vapormate is approved in the US, Linde plans to produce Vapormate on site Linde making more portable vaporizing machine 13
Thank you California Citrus Research Board for financial support TASC grant The Linde Corporation for providing Vapormate and technical support The Contained Research Facility staff for their support in rearing and providing Asian Citrus Psyllid Spencer Walse and Associates Beth Grafton Cardwell and Associates Joseph Morse and Associates Questions?? 14