1. 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

2. 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 VS 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.

3. 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 fl oz
26 Feb, 25 Mar Mar & 8 Apr
8. Closer SC r/w Radiant SC r/w Lannate LV
2.0 fl oz fl oz fl oz
25 Feb, 8 Apr Mar 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 fl oz fl oz fl oz
26 Feb Mar Mar Apr
12. Exirel 10SE r/w Radiant SC
13.5 fl oz fl oz
25 Feb, 25 Mar Mar & 8 Apr
13. Exirel 10SE f/b Radiant SC f/b Lannate LV
13.5 fl oz fl oz fl oz
14. Radiant SC r/w Movento r/w Lannate LV
7.5 fl oz fl oz fl oz
26 Feb, 8 Apr Mar Mar
Conventional Insecticide Treatment Rates and Dates
ml/4gal (0.25 vol/vol) added to foliar spray mixtures.

4. 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 % v/v
2.0 pt % 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
ml/4gal (0.25 vol/vol) added to foliar spray mixtures.

5. Conventional insecticides: Post treatment averages Thrips Larvae per 5 plants

6. Conventional insecticides: Post treatment averages Adult OT per 5 plants

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

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

9. Conventional insecticides: Post treatment averages All Thrips per 5 plants

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

11. Percentage IYSV symptomatic plant, bulb yield as kg per 0
Percentage IYSV symptomatic plant, bulb yield as kg per 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
5.00 a
12.86 a
14.18 a
Closer SC r/w Radiant SC r/w Lannate LV
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
14.91 a
16.44 a
Exirel 10SE r/w Radiant SC
13.13 a
14.47 a
Exirel 10SE f/b Radiant SC f/b Lannate LV
11.84 a
13.05 a
Radiant SC r/w Movento r/w Lannate LV
14.52 a
16.01 a
Means within columns followed by the same letter are not significantly different via LSD, P>0.05

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

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

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

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

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

17. Natural Source Products: Percentage of IYSV symptomatic plants and Onion bulb yields, 2013
Treatment
fl oz/acre
Percentage IYSV
Onion Kg/ 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 fl oz 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 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.

18. 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).

19. 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

20. 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

21. 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

22. 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