Research Advisory Board Insecticide Evaluations for Thrips Control In California Low Desert Onions During 2013 And a Three Year Research Summary Eric Natwick UC Cooperative Extension Imperial County Supported by CA Garlic and Onion Research Advisory Board

2013 Thrips Control Efficacy Studies at UC Desert Research & Extension Center Two thrips insecticide efficacy trials were completed on dehydrator onions in 2013. Thrips species included: Western flower thrips (WFT) Frankliniella occidentalis (Pergande) and Onion thrips (OT) Thrips tabaci Lindeman Objective: evaluate insecticide efficacy against OT and WFT. Two experiments: 1st convectional, synthetically derived insecticidal products. 2nd primarily insecticides derived as products of a natural source or from microbial fermentation. Onion (White Creole) 6 seedlines per 40” beds sown on 19 Oct 2012; plots were 4-beds (13.3 ft) wide by 50 ft long. Insecticides applied using a Lee Spider Spray TracTractor 4-row sprayer with three TJ-60 11003VS nozzles per row; 3 nozzles per bed delivering 53 gpa at 30 psi. The adjuvant, DyneAmic (Helena Chemical Co.), was added to all insecticidal spray mixtures at 0.25% vol/vol.

Conventional Insecticide Treatment Rates and Dates Rate/acre Application Dates 1. Untreated -------- -------------- 2. Movento 5.0 fl oz 26 Feb, 12 & 25 Mar, 8Apr 3. Lannate LV 48.0 fl oz 26 Feb, 12 & 25 Mar, 8 Apr 4. Radiant SC 7.5 fl oz 5. Exirel 10SE 13.5 fl oz 6. Closer SC 2.0 fl oz 7. Closer SC r/w Radiant SC 2.0 fl oz 7.5 fl oz 26 Feb, 25 Mar 12 Mar & 8 Apr 8. Closer SC r/w Radiant SC r/w Lannate LV 2.0 fl oz 7.5 fl oz 48.0 fl oz 25 Feb, 8 Apr 12 Mar 25 Mar 9. Torac 15EC 24.0 fl oz 10. Torac 22 SC 16.3 fl oz 11. Torac 15EC f/b Radiant f/b Torac 15EC f/b Lannate LV 24.0 fl oz 7.5 fl oz 24.0 fl oz 48.0 fl oz 26 Feb 12 Mar 25 Mar 8 Apr 12. Exirel 10SE r/w Radiant SC 13.5 fl oz 7.5 fl oz 25 Feb, 25 Mar 12 Mar & 8 Apr 13. Exirel 10SE f/b Radiant SC f/b Lannate LV 13.5 fl oz 7.5 fl oz 48.0 fl oz 14. Radiant SC r/w Movento r/w Lannate LV 7.5 fl oz 5.0 fl oz 48.0 fl oz 26 Feb, 8 Apr 12 Mar 25 Mar Conventional Insecticide Treatment Rates and Dates Dyne-Amic @ 37.8 ml/4gal (0.25 vol/vol) added to foliar spray mixtures.

Fermentation Product Insecticides: Treatment Rates and Application Dates Rate/acre Application Dates Untreated -------- -------------- Entrust SC 6.0 fl oz 26 Feb, 12, 25 Mar & 8 Apr Aza-Direct + M-Pede 1.5 pt 2% v/v 2.0 pt 1% v/v M-Pede 2% v/v Entrust SC f/b Agri-Mek 0.15EC f/b Aza-Direct 12.0 fl oz 1.5 pt 26 Feb & 8 Apr 12 Mar 25 Mar Grandevo 2.0 lb 3.0 lb MBI-206EP 2.0 gal MBI-206EP r/w Radiant 7.0 fl oz 26 Feb, 25 Mar 12 Mar & 8 Apr Dyne-Amic @ 37.8 ml/4gal (0.25 vol/vol) added to foliar spray mixtures.

Conventional insecticides: Post treatment averages Thrips Larvae per 5 plants

Conventional insecticides: Post treatment averages Adult OT per 5 plants

Conventional insecticides: post treatment WFT averages per 5 plants Adult WFT per 5 plants

Conventional insecticides: Post treatment averages All Adult Thrips per 5 plants

Conventional insecticides: Post treatment averages All Thrips per 5 plants

Conventional insecticides: Percentage of OT among all adult thrips % OT Adults

Percentage IYSV symptomatic plant, bulb yield as kg per 0 Percentage IYSV symptomatic plant, bulb yield as kg per 0.002 acre and tons per acre Treatment fl oz/a Percentage IYSV Kg/0.002 acre Tons per acre 17 Apr 24 Apr 1 May 16 May Untreated ------- 1.00 a 0.00 a 4.00 a 10.29 a 11.34 a Movento 5.0 12.20 a 13.45 a Lannate LV 48.0 2.00 a 13.95 a 15.37 a Radiant SC 7.5 13.38 a 14.74 a Exirel 10SE 13.5 14.15 a 15.59 a Closer SC 2.0 12.16 a 13.40 a Closer SC r/w Radiant SC 2.0 7.5 5.00 a 12.86 a 14.18 a Closer SC r/w Radiant SC r/w Lannate LV 2.0 7.5 48.0 13.90 a 15.32 a Torac 15EC 24.0 3.00 a 10.72 a 11.81 a Torac 22 SC 16.3 11.12 a 12.25 a Torac 15EC f/b Radiant f/b Torac 15EC f/b Lannate LV 24.0 7.5 24.0 48.0 14.91 a 16.44 a Exirel 10SE r/w Radiant SC 13.5 7.5 13.13 a 14.47 a Exirel 10SE f/b Radiant SC f/b Lannate LV 13.5 7.5 48.0 11.84 a 13.05 a Radiant SC r/w Movento r/w Lannate LV 7.5 5.0 48.0 14.52 a 16.01 a Means within columns followed by the same letter are not significantly different via LSD, P>0.05

Natural source insecticides: Post treatment averages Thrips Larvae per 5 plants b bc b d b cd bc cd a Larvae / 5 plants

Natural source insecticides: Post treatment averages OT Adults per 5 plants OT adults / 5 plants

Natural source insecticides: Post treatment averages WFT Adults per 5 plants WFT adults / 5 plants

Natural source insecticides: Post treatment averages Adult Thrips per 5 plants Adult thrips / 5 plants

Natural source insecticides: Post treatment averages All Thrips per 5 plants Thrips / 5 plants

Natural Source Products: Percentage of IYSV symptomatic plants and Onion bulb yields, 2013 Treatment fl oz/acre Percentage IYSV Onion Kg/0.002 acre Tons of onions per acre 17 Apr 24 Apr 1 May 16 May Untreated -------- 0.00 a 3.00 a 6.08 a 6.70 a Entrust SC 6.0 fl oz 1.00 a 7.75 a 8.54 a Aza-Direct + M-Pede 1.5 pt 2% v/v 7.30 a 8.05 a 2.0 pt 1% v/v 6.04 a 6.66 a M-Pede 2% v/v 2.00 a 7.91 a 8.72 a Entrust SC f/b Agri-Mek 0.15EC f/b Aza-Direct 6.0 fl oz 12.0 fl oz 1.5 pt 5.00 a 6.97 a 7.68 a Grandevo 2.0 lb 5.87 a 6.47 a 3.0 lb 7.13 a 7.85 a MBI-206EP 2.0 gal 8.32 a 9.17 a MBI-206EP r/w Radiant 2.0 gal 7.0 fl oz 6.53 a 7.19 a Means within columns followed by the same letter are not significantly different via LSD, P>0.05.

THRIPS MANAGEMENT IN ONIONS Don’t plant onions near small grain crops. Overhead irrigation may help suppress thrips populations. Control thrips before the early bulb. Onions can tolerate higher thrips populations near harvest. Randomly sample entire onion plants by pulling leaves apart and counting all thrips using a hand lens, on the inner leaves near the bulb, as well as those under the leaf folds. Sample at least 5 plants from 4 separate areas of the field. A suggested treatment threshold is 30 thrips per plant mid-season (lower for very young plants and higher for larger mature plants).

Conventional Insecticides for Thrips Control Tetronic & Tetramic acid derivatives (MoA interferes with lipid synthesis & IGR; 23) Movento® (spirotetramat) Bayer CropScience Neonicotinoids (MoA nicotinic acetylcholine receptor agonist; A4) Assail (a.i. acetamiprid) Spinosyns: (MoA nicotinic acetylcholine receptor allosteric activator; 5) Success® (a.i. spinosad) Dow AgroSciences Radiant® SC (a.i. spinetoram) Dow AgroSciences Carbamates: (MoA acetylcholinesterase inhibitor; A1) Lannate® (a.i. methomyl) DuPont Vydate ® (a.i. oxamyl) DuPont dry bulb onion supplemental label Pyrethroids: (MoA sodium channel modulator; 3) (several others not listed) Mustang® (a.i. zeta-cypermethrin) FMC Corp. Warrior® (a.i. lambda-cyhalothrin) Syngenta METI insecticides & acaricides: (MoA METI; 21A) Torac (a.i. tolfenpyrad; Nichino Americas) Not available; Check for a Section 18 Label Avermectins: (MoA cholride channel activator; 6) Agri-Mek (a.i. abamectin) Syngenta Others: (MoA Unknown) Grandevo (a.i. Chromobacterium subtsugae strain PRAA4-1) Marrone Bio Innovations, Inc. Aza-Direct (Gowan Company) & various other products with the a.i. Azadirachtin M-Pede (a.i. potassium salts of fatty acids) Gowan Company

Thrips Control Insecticides for Organic Production Spinosyns: (MoA 5) Entrust® (a.i. spinosad) Dow AgroSciences Insecticidal Soaps (membrane disruption) M-Pede (a.i. potassium salts of fatty acids) Gowan Company Others: (MoA Unknown) Grandevo (a.i. Chromobacterium subtsugae strain PRAA4-1) Marrone Bio Innovations, Inc. MBI-206EP (a.i. bacteria Burkholderia sp. strain A396 ) Not Registered in California at time of this publication Feb 2014. Aza-Direct (a.i. azadirachtin) (Gowan Company) & various other products with the a.i. Azadirachtin

Summary of my past three years thrips control research on onion Several new insecticidal active ingredients were evaluated for thrips control efficacy: Tolfenpyrad (Torac) not registered for use as of Feb 2014. Spirotetramat (Movento) Sulfoxaflor (Closer) not registered for use in California as of Feb 2014. Cyantraniliprole (Exirel) not registered for use as of Feb 2014. a.i. Chromobacterium subtsugae strain PRAA4-1 (Grandevo) a.i. bacteria Burkholderia sp. strain A396 (MBI-206EP) Evaluations of active ingredients from various IRAC MoA groups were evaluated as tank mixture partners Evaluations of active ingredients from various IRAC MoA groups were evaluated for overall efficacy in rotational schemes for efficacy against OT and WFT

ACKNOWLEDGEMENTS I wish to thank the California Garlic & Onion Research Advisory Board for their generous funding support of my thrips research. I also wish to thank the following agricultural crop protection chemicals companies for their generous in-kind support of supplying the products evaluated and for their generous monitory support of my thrips research on onions: Amvac Chemical Corporation Helena Chemical Co Bayer CropScience Marrone Bio Innovations Inc. Dow AgroSciences Nichino America, Inc. DuPont Syngenta Crop Protection, LLC FMC Corporation United Phosphorus, Inc. Gowan Company