Managing Arthropod Pests in Strawberries A Twenty Year Odyssey Frank Zalom Dept. of Entomology University of California, Davis ENTOMOLOGY Key Arthropod Pests Spider Mites Lygus Bugs Lepidoptera corn earworm beet armyworm cutworms Thrips Occasional/Unusual Arthropod Pests Cyclamen Mite Greenhouse Whitefly Vinegar Flies Light Brown Apple Moth My approach to pest management Crisis - Management - short term longer term Lygus bug Lygus bug Management - Sampling Thresholds Phenology model Control - Manage alternate hosts Insecticides Bug-vacs Lygus bug Management - Sampling Thresholds Phenology model Lygus bug Control - Manage alternate hosts Insecticides Bug-vacs?? Lygus - issues and needs Loss of Lannate (methomyl) Pyrethroid and OP resistance New products and combinations Rimon (novaluron) - Section 18 Clutch (clothianidin) - IR-4 Beleaf (flonicamid) - IR-4 Monitoring and treatment timing Lygus life cycle and seasonal cycle - Oxnard Application methodology (bioassays) Lygus species composition Lygus - issues Pyrethroid resistance Weeds Danitol - fenpropathrin First Year Prunedale, July, 2008 Second Year Lygus collected from - Weeds First Year Field Second Year Field 10.67 oz in 100 gal 2007 sprays - 1 Brigade + 2 Danitol 2008 sprays - 3 Brigade + 1 Danitol Two spotted spider mite Tetranychus urticae Two spotted spider mite Tetranychus urticae Management - Chemicals - monitoring and thresholds Varietal susceptibility (20+ years) Plant vigor - vernalization, day-neutral varieties Biological controls - predatory mites Two spotted spider mite Acaricides - new products registered since 1995 Product Active Ingredient Primary Target Site of Action IRAC # Kelthane Dicofol Unknown mode of action Uncl. Vendex Fenbutatin oxide Oxidative phosphorylation inhibitor 12B Omite Propargite Oxidative phosphorylation inhibitor 12C Agri-Mek Abamectin Chloride channel activator 6 Savey Hexythiazox Unknown mode of action (mite growth regulator) 10A Zeal Etoxazole Unknown mode of action (mite growth regulator) 10B Acramite Bifenazate Neuronal inhibitor (unknown mode of action) 25 Oberon Spiromesifen Inhibitor of lipid synthesis 23 Kanemite Acequinocyl Site III electron transport inhibitor 20B Fujimite 1 Fenpyroximate Site I electron transport inhibitor 21 Ecotrol Organic oils Botanicals, exempt from tolerance Uncl. GC Mite Organic oils & Botanicals, exempt from tolerance Uncl. extracts 1 Not registered for use on strawberries VarietalVarietal susceptibilitysusceptibility SelvaSelva 3500 Day Neutral Varieties 3000 Treated Varietal susceptibility Untreated 2500 UC Davis Strawberry 2000 Field Station, 1500 Watsonville, 2008 1000 500 Total avg yield (g/season/plant) 0 3.114-3 3.149-8 3.92-6 Albion Portola DiamanteMonterey San Andreas 4500 Short Day Varieties, 2008 4000 Treated 3500 Untreated 3000 2500 2000 1500 1000 500 Total avg yield (g/season/plant) 0 4.2-5 4.38-4 4.9-5 2.132-6 4.44-603 CaminoPalomarVentana Predatory mites Almost 30% of California strawberry growers release or conserve predatory mites. Acaricide selectivity is important Phytoseiulus persimilis Acaricide selectivity Contact and residual bioassays on leaves of treated strawberry plants up to 37 days after application Direct and side effects of - Acaramite = Bifenazate Agri-mek = Abamectin Kanemite = Acequinocyl Oberon = Spiromesifen Zeal = Etoxazole Fujimite = Fenpyroximate NR Mean ± SD percent P. persimilis female mortality 72 h after exposure strawberry leaflets treated with the label dose. Mean ± SD % mortality Days after treatment Trea tme nt 3 6 10 >14 IOBC Control 0a 0a 0a 0a A Bifenaz a te 0a 0a 0a 0a A Etoxazole 0a 0a 0a 0a A Spirom esifen 0a 0a 0a 0a A Abam ectin 26.4±1 2.3b 26.4±1 2.3b 0a 0a A Fenpy roxima te 100c 100c 100b 0a B Acequino cyl 100c 0a 0a 0a A Within columns means (±SD) followed by the same letter do not differ significantly at P=0.05 by LSD. IOBC categories: A = short lived (<5 d), B = slightly persistent (5-15 d), C = moderately persistent (16-30 d), D = persistent (>30 d) Mean ± SD P. persimilis fecundity (eggs/female/day) recorded 72 h after exposure to strawberry leaflets treated with the label dose of formulated products. Days after treatment Trea tment 3 6 10 14 17 24 30 37 Contro l 4.2±0.3a 4.1±0.3a 4.1±0.2a 4.0±0.3a 3.8±0.3a 4.3±0.2a 4.3±0.1a 4.0±0.3a Bifenazate 0.0±0.0c 1.9±0.1b 1.6±0.1b 2.9±0.2b 4.4±0.2a 4.5±0.2a 4.4±0.1a 4.0±0.3a Etoxazo le 1.8±0.2b 1.5±0.2bc 1.2±0 .2b 3.1±0.2b 4.4±0.2a 4.4±0.2a 4.4±0.1a 4.0±0.1a Sp iromes ifen 0.1±0.0c 0.8±0.2cd 1.1±0.1b 4.1±0.2a 4.1±0.2a 4.2±0.2a 4.0±0.3a 4.0±0.3a Abamect in 1.2±0.1b 1.7±0.4b 1.7±0.3b 3.3±0.2b 4.1±0.2a 4.1±0.1a 4.1±0.1a 4.2±0.2a Fenpy roximate 0.3±0.1c 0.4±0.2d 0.2±0.1c 1.7±0.1c 1.3±0.1b 1.3±0.2b 4.2±0.2a 4.1±0.2a Acequ inocy l 1.4±0.3b 3.9±0.2a 3.9±0.3a 4.1±0.3a 4.4±0.2a 4.4±0.1a 4.3±0.1a 4.3±0.1a Within column means (±SD) followed by the same letter do not differ significantly at P=0.05 by LSD. Mean ± SD P. persimilis fertility recorded 72 h after exposure to strawberry leaflets treated with the label dose of formulated products. Days after treatment Trea tment 3 6 10 14 17 24 30 37 Contro l 96.7±1.4a 98.3±0.8a 98.0±1.0a 97.8±1.3a 97.4±1.3a 99.0±1.0a 100±0.0a 97.8±1.4a Bifenazate 0.0±0.0b 99.0±1.0a 100±0.0a 97.9±3.4a 62.5±3.4c 99.1±0.9a 99.2±0.8a 98.5±0.9a Etoxazo le 0.0±0.0b 0.0±0.0b 0.0±0.0b 0.0±0.0b 0.0±0.0d 0.0±0.0b 0.0±0.0b 0.0±0.0b Sp iromes ifen 0.0±0.0b 0.0±0.0b 3.9±2.4b 97.7±1.1a 76.7±5.3b 97.3±1.1a 99.2±0.8a 97.4±1.4a Abamect in 0.0±0.0b 99.1±0.9a 99.2±0.9a 98.6±0.6a 97.0±0.9a 98.1±1.2a 99.2±0.8a 97.9±1.3a Fenpy roximate 0.0±0.0b 0.0±0.0b 0.0±0.0b 0.0±0.0b 0.0±0.0d 0.0±0.0b 0.0±0.0b 0.0±0.0b Acequ inocy l 99.2±0.8a 100±0.0a 99.1±0.8a 99.2±0.8a 99.0±0.6a 98.7±0.8a 99.1±0.6a 97.2±1.4a Within column means (±SD) followed by the same letter do not differ significantly at P=0.05 by LSD. Total effects (E) of acaricide residues on P. persimilis recorded 72 h after exposure to strawberry leaflets treated with the labeled dose of formulated products. Days after treatment Treat ment 3 6 10 14 17 24 30 37 IOBC Bifena zate 100 54 61 29 26 0 0 0 B Etoxa zole 100 100 100 100 100 100 100 100 D Spiromes ifen 100 100 99 0 12 0 0 0 B Abamect in 100 70 59 19 3 2 1 2 B Fenp yroximate 100 100 100 100 100 100 100 100 D Aceq uinocyl 100 5 6 0 0 0 0 0 A IOBC categories: A = short lived (<5 d), B = slightly persistent (5-15 d), C = moderately persistent (16-30 d), D = persistent (>30 d) Lepidoptera Damage Fruit feeding Crown damage Processing corn earworm beet armyworm cutworms Lepidoptera Issues and needs Lannate alternatives Sampling Phenology models corn earworm beet armyworm cutworms Lepidoptera Corn Earworm Control, Orange County H zea damaged Treatment Rate (form/A) fruit per 20 plants Untreated -- 12.75 ± 5.68 Lannate 1.0 bl 3.67 ± 0.58* Intrepid 12.0 fl oz 4.67 ± 3.06* Rimon1 12.0 fl oz 3.00 ± 1.41* Synapse 24WG 2 2.0 oz 3.00 ± 2.65* Synapse 24WG 2 3.0 oz 4.33 ± 1.53* Radiant SG 6.0 fl oz 4.00 ± 2.65* 1 Section 18 emergency registration 2 Not registered for use on strawberries Application date 4/13/2007 Harvest date 5/2/2007 ANOV statistics - F=4.0938, df=6,20, P=0.0140 Western Flower Thrips Frankliniella occidentalis Damage - • 'bronzing' from fruit feeding • flower abortion from feeding on strawberry blossoms Threshold - 10 thrips per flower Type I Bronzing Bronzing 3 types identified Type I Type III Type II Watsonville Bronzing Experiment (Impact sprinklers and no sprinklers with 6 treatments) I II I Treatments Exp. I: 1. center strip/Mar. 1 4 ex1 5 3 1 4 2 5 3 6 1 4 ex2 5 3 2. clear plastic/Dec. 2 5 ex1 4 1 2 5 1 6 2 5 2 5 ex2 4 1 3. gray/green mulch 6 3 ex1 6 2 3 6 4 3 1 4 6 3 ex2 6 2 4. shadecloth hoops 5. deficit irrigation 3 5 ex2 1 4 1 6 3 5 6 3 3 5 ex1 1 4 6. commercial spray 4 1 ex2 2 5 2 5 4 1 2 5 4 1 ex1 2 5 6 2 ex2 3 6 3 4 2 6 4 1 6 2 ex1 3 6 Sprinklers run for 15 minutes (= 1/8 to 1/4 inch precipitation) after each harvest (twice a week) from April 23 to June 21 Deficit irrigation - drip tapes shut off from April 11 to June 4 Type III fruit bronzing as a function of treatments, 2001 Number of bronzed fruit Treatment Sprinkling Mean ± SEM Clear, Full in Dec Not Sprinkled 142.0 ± 6.8 B Clear, Strip in March Not Sprinkled 176.3 ± 32.1 AB Commercial chemical Not Sprinkled 58.5 ± 5.9 CD Gray/Green in Dec Not Sprinkled 168.5 ± 15.8 AB Irrig.