INTEGRATED PEST MANAGEMENT OF ARTHROPODS ON HOPS Concise Report on Work Completed in 2015 B. RESEARCH & EXTENSION INVESTIGATORS Douglas B. Walsh, PhD Sally O Neal Coordinator, Integrated Pest Management Extension Outreach Specialist Dan Groenendale Field Research Director Cooperators Laura Lavine, WSU Entomology Tora Brooks Courtney Grula, WSU Entomology Arthropod Quantifier David Gent, USDA-ARS Gary Grove, WSU Plant Pathology Environmental and Agricultural Fang Zhu, WSU Entomology Entomology Laboratory Troy Peters, WSU Bio Sys Eng Washington State University Tom Marsh, WSU Econ Sci Irrigated Agriculture Res. and Ext. Ctr. Jennifer Sherman, WSU Sociology 24106 N. Bunn Rd., Prosser, WA 99350 Adekunle Adesanya, WSU Entomology Tel. 509-786-9287 Jim Barbour, UI Entomology Email dwalsh@wsu.edu Website http://ipm.wsu.edu Email dwalsh@wsu.edu Websites http://ipm.wsu.edu or dougwalshentomology.com Phone: 509-786-9287
OVERALL PROJECT OBJECTIVES: The primary objective of this project is to provide pest management recommendations for the everchanging hop arthropod IPM program.
THIRTEEEN RESEARCH OBJECTIVES WERE PLANED FOR 2015 These objectves were a combination of research, service and Extension
Objectives a) Field test candidate compounds for their efficacy against spider mites and aphids Aphid populations failed to develop in the research hopyards we had dedicated for these studies due to the hot spring. We completed efficacy trials against spider mites with the candidate acaricides GWN-10409, GWN- 10410, GWN-10285, pyridaben, abamectin, spirodiclofen, spirotetramat, clofentezine, acequinocyl, bifenazate, propargite, and hexythiazox, Several of these acaricides provided effective suppression of mite populations for up to 3 weeks
Objective b) Field test efficacy of insecticides on other pests if opportunities arise- Black Vine Weevils Our trials included applying candidate insecticides in banded applications followed by sprinkler irrigation as well as directly chemigating insecticides via the fixed drip irrigation systems. Specific interest is directed towards the candidate insecticide cyantraniliprole (Verimark ). Cyantraniliprole has demonstrated effective weevil control in other crops, with solid efficacy results specifically in PNW strawberries. Other candidate insecticides applied included ethoprop (Mocap) and thiamethoxam (Platinum)
Objective c) Evaluate the impact of candidate pesticides on non-target beneficial arthropods. We have completed studies on the residual toxicity of etoxazole (Zeal) to the progeny (egg hatch) of female G. occidentalis that feed on etoxazole-treated spider mite eggs. Zeal had no direct toxic effects on predatory mite adults but exposure of the adult females reduced the proportion of eggs that hatch when compared to eggs laid by female predatory mites with no history of exposure to Zeal
Objective d) Develop baseline dose response curves of spider mite populations susceptible to hexythiozox and etoxazole For etoxazole we have tested concentrations as low as 1/175 of the labeled field rate on our acaracide-naïve mite population and had close to 100% mortality on eggs that were laid within 24 hrs. Eggs prove substantially more resilient after they have been laid and permitted to develop for 96 hrs. Additionally we have observed greater tolerance among field-collected mite populations to the ovicidal acaricides compared to our laboratory population of acaricide-naïve
Objective e) Develop discriminating doses of candidate ovicidal miticides that can be used to rapidly identify the prevalence of tolerance or resistance in a spider mite population. We have developed several bioassay approaches to expand and standardize our evaluation methodology. 1) Direct exposure of cohorts of spider mite eggs to ovicidal avaricides at varying time intervals after the eggs have been laid and permitted to age; 2) Direct spray of gravid females with ovicidal acaricides and testing the subsequent hatch rates of the eggs laid by females exposed to varying rates of adulticides compared to hatch rates of eggs laid by gravid female spider mites that were not exposed to ovicidal acaricides; and 3) treating plant materials with ovicidal acaricids and then introducing gravid female spider mites at varying times following treatment to see how long the acaricides prove toxic to eggs.
Objective g) Establish mite colonies and, through constant and consistent exposure of the mite populations contained within these colonies, breed resistance into these mite populations. Susceptible Two-spotted spider mite colony Following 2 years of consistent acaricide applications, the final concentrations for the selection of these three acaricide-resistant populations are: 690 mg a.i./l for abamectin (3,000 times higher than the LC 50 of susceptible), 899 mg a.i./l for bifenazate (1,096 times higher than the LC 50 of susceptible), 12,000 mg a.i./l for bifenthrin (670 times higher than the LC 50 of susceptible). Bioassays revealed the resistance ratio (RR) of abamectin-resistant strain (Abamectin R ) was 1,539-fold, the RR of the bifenazate-resistant strain (Bifenazate R ) was 189-fold, and the RR of bifenthrin-resistant strain (Bifenthrin R ) was 253-fold.
Objective i) Develop and validate robust diagnostics including a quantitative sequencing protocol and PCR to follow insecticide/acaracidebased resistance frequencies in the field.
Mutations in cytb confer bifenazate resistance N- TERM C- TER M G126 P262 I136 Qo site D161 S141 Van Leeuwen et al. 2008; 2010 Piraneo et al. 2015 Mitochondria cytochrome b (cytb)-target of bifenazate
Abamectin Decreased target site sensitivity Voltage-gated sodium channel (VGSC) Acetylcholinesterase (AchE) Glutamate-gated chloride channel (GluCl) Cytochrome b (cytb) Not Observed Increased metabolic detoxification Cytochrome P450 monooxygenases (P450s) Hydrolases Still Testing Glutathione S-transferases (GSTs)
We confirmed upregulation of mrna in 2014- collected mites associated with abamectin field failures CYP392D8 (Clan 2) ** Relative mrna expression ** Field failures with abamectin in 2014 ** ** ** CYP392D8 likely contributes to abamectin resistance ** P< 0.01 * P<0.05 Piraneo et al. 2015 Scientific Reports
Objective j) Evaluate the interactions of plant nutrition with arthropod pest abundance and disease severity. We had a problem occur when we accidently left a valve open and every plot in the trial was over-fertilized. Each plot received an additional 190# of N. oops To spin this in a positive light, we are now definitely conducting research on hops that are truly over-fertilized. We proceeded to conduct the studies we proposed. No aphids, few mites, and a little mildew. No consistency.
Yields, of hop cones cv. Cascade dried to 8% moisture from 2015 fertilizer trials. Yield estimate dry lbs/acre±se Mean Square (df= 9) 155,808 ns error (df=70) 84,614 Dry Drip Cutoff Spray 120# 301# 6/19 Yes 1265± 67 90# 271# 6/19 Yes 1058±130 120# 301# 7/17 Yes 1058±130 90# 271# 7/17 Yes 1122± 68 120# 337# 8/21 Yes 1111±138 120# 301# 6/19 No 1467±126 90# 271# 6/19 No 1366± 84 120# 301# 7/17 No 1204± 76 90# 271# 7/17 No 1248±106 120# 337# 8/21 No 1076± 62
Alpha and beta acid content of hop cones and HSI cv. Cascade dried to 8% moisture from 2015 fertilizer trials. % α acid % β acid 1 HSI Mean Square (df=9) 1.70** 0.413 ns 0.002710* error (df=30) 0.39 0.624 0.000019 Dry Drip Cutoff Spray 120# 301# 6/19 Yes 6.00±0.18 abc 6.22±0.42 0.21±0.0016 b 90# 271# 6/19 Yes 5.37±0.47 abc 5.97±0.71 0.23±0.0010 a 120# 301# 7/17 Yes 5.35±0.34 bc 6.20±0.41 0.23±0.0014 a 90# 271# 7/17 Yes 5.02±0.36 c 5.62±0.27 0.23±0.0010 a 120# 337# 8/21 Yes 5.30±0.38 bc 6.27±0.54 0.23±0.0027 a 120# 301# 6/19 No 6.50±0.15 abc 6.77±0.26 0.19±0.0009 c 90# 271# 6/19 No 6.60±0.31 ab 6.45±0.13 d 0.17±0.0019 120# 301# 7/17 No 6.45±0.26 abc 6.57±0.22 d 0.17±0.0037 90# 271# 7/17 No 6.87±0.24 a 6.25±0.40 d 0.17±0.0026 120# 337# 8/21 No 5.97±0.31 abc 6.05±0.23 d 0.17±0.0027 */ ANOVA results pass the F-test at p<0.05; **/ ANOVA results pass the F-test at p<0.01 ns/ No significant differences by failure to pass the F-test in one-way ANOVA 1/treatment means separated by an uncommon letter are significantly are significantly different by Tukey HSD at p<0.05.
One-Way Analysis of Variance for factors including sprayed with pesticides, #N applied dry pre-stringing, total #N applied, and fertilizer application cutoff date, 7/22, 8/3, and on yield estimate in pounds dry cones at 8% moisture content, percent alpha and beta acids content, and HSI. Factor df= Yield estimate dry lbs/acre±se % α acid % β acid HSI Mean square 1 449835* 11.45** 1.30 0.02333** error 38 8846 0.41 0.56 0.00004 a Pesticide spray Yes (n=20) 1113±48 5.41±0.16 a 6.06±0.20 0.18±0.0016 a b No (n=20) 1273±45 6.48±0.12 b 6.42±0.12 0.22±0.0013 b Factor df= Yield estimate dry lbs/acre±se % α acid % β acid HSI Mean square 1 71.5 ns 0.015 ns 0.726 ns 0.00015 ns error 38 93912 0.701 0.571.000060 Pre-Sting N 90# (n=16) 1199±52 5.969±0.210 6.07±0.189 0.200±0.006 120# (n=24) 1197±45 5.929± 0.178 6.35±0.154 0.200±0.005 Factor df= Yield estimate dry lbs/acre±se % α acid % β acid HSI Mean square 2 128159 ns 0.518 ns 0.574 ns 0.0002 ns error 37 91804 0.700 0.575 0.0004 Total N 361# (n=16) 1199±52 5.97±0.21 6.07±0.190 0.200±0.006 421# (n=16) 1249±56 6.07±0.21 6.44±0.190 0.200±0.006 457# (n=8) 1093±73 5.64±0.30 6.16±0.268 0.199±0.009 Factor df= Yield estimate dry lbs/acre±se % α acid % β acid HSI Mean square 2 245155 ns 0.622 ns 0.180 ns 0.0005 ns error 37 88766 0.693 0.60 0.0006 Fertilizer cutoff 6/19 (n=16) 1289±53 6.12±0.20 6.36±0.19 0.200±0.006 7/17 (n=16) 1158±53 5.92±0.20 6.16±0.19 0.200±0.006 8/26 (n=8) 1093±74 5.64±0.29 6.16±0.27 0.199±0.009
Nutrient levels in sampled Cascade hops harvested from plots that received varying N fertilization treatments, fertilizer cutoff dates and were sprayed or not sprayed for pest suppression. ANOVA (df= 9, 30) p< N% P% K% Ca% Mg% S% Zn Mn Cu Fe B Na Dry Drip Cutoff Spray ns 0.01** ns ns 0.01** 0.01** ns ns ns ns ns ns 120# 301# 6/19 Yes 3.93 0.59 a 2.82 1.59 0.57 a 0.29 a 31.3 50.3 7.14 502 30.5 65.6 120# 301# 7/17 Yes 3.83 0.54 ab 2.67 1.53 0.56 ab 0.26 ab 33.6 50.7 7.33 877 27.8 69.2 90# 271 6/19 Yes 3.93 0.53 ab 2.77 1.65 0.53 ab 0.26 ab 31.3 53.5 6.86 808 26.6 74.2 90# 271# 7/17 Yes 3.96 0.53 ab 2.74 1.54 0.51 ab 0.24 ab 29.0 44.3 5.88 788 28.3 66.0 120# 337# 8/21 Yes 3.90 0.51 ab 2.63 1.70 0.55 ab 0.27 ab 34.9 75.4 8.72 887 33.7 92.6 120# 301# 6/19 No 3.73 0.57 ab 2.80 1.54 0.49 ab 0.23 b 29.0 48.2 6.54 699 29.1 71.4 90# 271# 6/19 No 3.77 0.50 ab 2.55 1.56 0.50 ab 0.24 ab 26.3 45.2 6.45 781 25.6 69.4 120# 301# 7/17 No 3.90 0.49 ab 2.44 1.52 0.49 ab 0.23 b 29.0 42.6 6.24 632 26.0 58.6 90# 271# 7/17 No 3.70 0.48 b 2.46 1.47 0.47 b 0.23 b 24.6 38.1 6.11 628 22.5 59.2 120# 337# 8/21 No 3.96 0.47 b 2.51 1.40 0.46 b 0.23 b 27.1 40.4 6.49 582 25.9 65.3 N, P, K, CA, Mg, and S are measured in percent dry matter. All other micronutrients are detailed in parts per million. **/ treatment mean separated by uncommon letters are significantly different in pair wise t-test at p<0.01
Objective k) Complete and publish the results from the 2014 and 2015 qualitative and quantitative survey of the honeybees, bumblebees, bees in the family Halictidae, and other pollinators present in hop yards. 12 10 Family: Halictidae Average capture of bees per trap/ week 8 6 4 Organic 2 0 Blueberries Concords The MS student completing tis project will be done by summer 2016 Hops Riparian Wine grape Halictids were by far the most abundant bee in all sampled crops
Objective l) Create an assessment of the impacts of various cultural and pest management practices deployed among our study sites and relate this to the data generated within Objective k. Will be part of the MS students Thesis Family: Halictidae: Primitive & solitary, ground nesting, native bee.
Objective 0) Collaborate with Jim Barbour in a California prionus mating disruption study. We did not do anything associated with this objective in 2015 We are still awaiting some regulatory decisions at EPA
PROJECT OBJECTIVES AND ACCOMPLISHMENTS NOT IN ORIGINAL RESEARCH PROPOSAL (August 2014) BUT CONDUCTED IN 2015 - IN BRIEF Objective n) Complete 3 rd Edition of the Field Guide for Integrated Pest Management in Hops. This IPM field guide was completed by WSU Sr. Outreach Coordinator Specialist Sally O Neal in November. The new version will soon be available online and 6,500 copies will be printed and distributed to interested parties at various hop and affiliated industry meetings
o) Compare ovicidal efficacy of clofentezine against spider mites resistant to abamectin and bifenthrin. We screened our abamectin- and bifenthrinresistant spider mite populations for their susceptibility to having their eggs die compared to our susceptible, acaricide-naïve population. There appears to be no cross-resistance between clofentezine and abamectin and bifenthrin.
PUBLICATIONS 2015 Piraneo, T. G., F. Zhu, J. Bull, M. D. Morales, L. C. Lavine, D. B. Walsh. 2015. Mechanisms of Tetranychus urticae chemical adaptation in Pacific Northwest hops field. Scientific Reports 5:17090 doi:10.1038/srep17090 http://www.nature.com/articles/srep17090 Walsh, D.B., S.D. O Neal, A.E. George, D.P. Groenendale, R.E. Henderson, G.M. Groenendale, & M.J. Hengel. In press. Evaluation of Pesticide Residues from Conventional, Organic, and Non-treated Hops on Conventionally Hopped, Late-Hopped and Wet-Hopped Beers. Journal of the American Society of Brewing Chemists.
2016 Next year we won t leave the valve open?
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