Cotton IPM Agent Training Phillip Roberts Cell: (229) 387-1659 January 9 (SW) and 10 (SE), 2017

UGA Pest Management Handbook Insecticides are used as a last resort Thresholds Must be effective Efficacy trials Susceptibility monitoring Resistance management Impact on natural enemies and other pests Optimal use patterns

Pest Patrol (Insect Updates) Growers and other users can subscribe for text message alerts when you post an update in two easy steps. Step one: Register online at www.syngentapestpatrol.com or register via text message by texting the corresponding short code word listed in the chart below to 97063. Step two: reply to the confirmation text they receive by texting the letter “y”, to complete their registration. Entomologist University or Region Short Code Word Blayne Reed Texas A&M University - Plainview pestpat1 Stephen Biles Texas A&M University – Port Lavaca pestpat2 David Kerns Louisiana State University pestpat4 Angus Catchot Mississippi State University pestpat5 Gus Lorenz University of Arkansas pestpat6 Jeremy Greene Clemson University pestpat7 Ames Herbert Virginia Tech University pestpat8 Dominic Reisig North Carolina State University pestpat9 Phillip Roberts University of Georgia pestpat10 Ron Smith Auburn University pestpat11 Scott Stewart University of Tennessee pestpat12

Pollinator Protection

Insecticide Applications per Acre Georgia Cotton, 1986-2015 Boll Weevil Era Two significant events have changed cotton IPM during the last 25 years. -Active BWEP- (does not include BWEP sprays) ----------Boll Weevil Free----------------------------------------- ----------------------Bt Cotton------------------------- Heliothines Boll Feeding Bugs (non-Lep pests) Source: Beltwide Cotton Conferences Proceedings

IPM Integrated Pest Management Decision Making Reducing Risk the use of ALL available control tactics so that economic losses and harmful environmental side effects are minimized. Decision Making Premium placed on insect scouting and KNOWLEDGE of the “SYSTEM”. Reducing Risk

Scouts / Consultants Offers great value to growers. 2017 Scout Schools Tifton: June 12th Midville: June 20th Offers great value to growers. Must know insect pest populations and species makeup to make Good Decisions. Economic Thresholds Insecticide Selection Timing of Applications Evaluation of Sprays Detection of Potential Problems Insects/Weeds/Fertility/ PGRs/Diseases/etc. Dr. Mike Toews, 2007

Current Insect Pest Management IPM is a proven program! Growers have gotten by…… Minimal scouting Great Technology A couple of stink bug sprays (Spray and Pray) What ifs??????? Thrips Plant Bugs Corn Earworm Spider Mites Whiteflies

Insecticide Resistance Monitoring Corn Earworm Bt Cotton Pyrethroids Tobacco Budworm Tobacco Thrips Neonics Soybean Looper Diamides Intrepid

Bt Technologies and Reduced CEW Efficacy Resistance Management plans are designed to protect the technology. Similar genes in both corn and cotton. Bt Corn Structured Refuge 20 percent non-Bt Bt Cotton Natural Refuge

Percentage reduction in corn ear injury (cm2) by Genuity VT3 PRO or VT2 PRO in Southern GA (average of 2 locations) Comparison of DKS 6694 (non-Bt) with DKS 6696 and/or DKS 6697 at Plains and Tifton, GA. Pdate 1 is for mid March to early April plantings and Pdate 2 is for late May to early June plantings. Buntin, UGA 2016

2016 Southeast diet overlay- Cry1Ac Location Source LC50 (ug/cm2) Lower FL Upper RGR (weight at 31.6 ug/cm2) RGR (instar at AL Non-Bt corn (2) 2.37 1.39 3.9 0.009 0.079 Benzon Lab 0.43 0.26 0.64 0.000 0.008 GA Non-Bt corn >31.60 . 0.105 0.365 NC* Non-Bt cotton* 10.79 3.59 30.35 ~0.069 ~0.28 NC Bt cotton 43.50 12.38 453.75 0.015 0.165 Tobacco 1.07 0.58 1.79 SC 1.74 0.32 3.68 Non-Bt cotton 53.87 19.38 498.00 0.049 0.403 VA Bt corn 74.93 12.04 7811 0.114 0.364 Tested at 0, 0.0316, 0.1, 0.316, 1, 3.16, 10, 31.6 ug/cm2 Except *NC non-Bt cotton tested at 0, 0.1, 1, 5, 10, 50, 100 ug/cm2

Bt Technologies and Reduced CEW Efficacy Resistance Management plans are designed to protect the technology. Similar genes in both corn and cotton. Bt Corn Structured Refuge 20 percent non-Bt Bt Cotton Natural Refuge

TBW remains Very Susceptible to Bt Cotton

CEW AVT (Pyrethroids) Season Mean Survival, Georgia 2006-2016 Pyrethroid applications in corn select for resistance. Greg Payne, West Georgia Call if field control issue! CEW AVT (Pyrethroids) Season Mean Survival, Georgia 2006-2016 No field problems, however we have rarely sprayed a pyrethroid for CEW control in any crop during recent years.

Bt Cottons are not IMMUNE to caterpillar pests Bt Cottons are not IMMUNE to caterpillar pests! IPM principles and practices are needed and provide value to the grower! o=no activity, +++=very good TBW Tobacco Budworm CEW Corn Earworm SBL Soybean Looper BAW Beet Armyworm FAW Fall WideStrike III (Vip3A+Cry1Ac+Cry1F) +++ Bollgard II (Cry1Ac+Cry2Ab) TwinLink (Cry1Ab+Cry2Ae) WideStrike (Cry1Ac+Cry1F) ++ 3-gene Bt Cottons -Resistance Management -Improved Efficacy In development: TwinLink Plus (Vip3A+Cry1Ab+Cry2Ae) Bollgard III (Vip3A+Cry1Ac+Cry2Ab)

Neonic Field Efficacy – Tobacco Thrips Tift Co. GA 2015 Untreated Neonic Seed Treatment

Tobacco Thrips Susceptibility to Neonics 55 percent (5 of 9) of Georgia collections classified as resistant in laboratory bioassays; LC50 Resistance Ratios ranged from 11 to 31 fold. Franklinella fusca resistance to neonicotinoid insecticides: an emerging challenge for cotton pest management in the eastern United States (Huseth et.al. Pest Management Science 2016). Susceptible 3.3% Susceptible 1.8%

Percent Thrips Control (immatures) 3 WAP Georgia (2001-2015, n=42) 2016 improved efficacy Loss of residual activity very apparent.

Resistance Monitoring 2013 to 2015 Soybean looper late instar larvae collected (~300) per location We used a 7 day diet incorporated insecticide (formulated product) bioassay on the F1 or F2 generation 3rd instar larvae Discriminating dose was 3X mean LC95 of our susceptible strain (Whalon et al. 2008) Dose response curves conducted as well

Discriminating Dose Response (95% Mortality Expected)

Discriminating Dose Response (95% Mortality Expected)

Insecticide Resistance Concerns Be informed Use IPM Scout Thresholds Conserve Natural Controls Predators and Parasitoids Manageable, but MANAGEMENT is the key

Bt Cottons are not IMMUNE to caterpillar pests Bt Cottons are not IMMUNE to caterpillar pests! IPM principles and practices are needed and provide value to the grower! o=no activity, +++=very good TBW Tobacco Budworm CEW Corn Earworm SBL Soybean Looper BAW Beet Armyworm FAW Fall WideStrike III (Vip3A+Cry1Ac+Cry1F) +++ Bollgard II (Cry1Ac+Cry2Ab) TwinLink (Cry1Ab+Cry2Ae) WideStrike (Cry1Ac+Cry1F) ++ 3-gene Bt Cottons -Resistance Management -Improved Efficacy In development: TwinLink Plus (Vip3A+Cry1Ab+Cry2Ae) Bollgard III (Vip3A+Cry1Ac+Cry2Ab)

CEW Escapes in Bt Cotton Generally associated near nodes at or below uppermost white bloom. Square damage more common in recent years (this is a change).

Bt Transgenic Cotton Tobacco Budworm excellent control Corn Earworm good control supplemental treatment may be needed. Larvae must feed on plant to ingest toxin. Threshold: 8 large (>1/4 inch) larvae per 100 plants Scouting CEW larvae generally found in or near the uppermost blooming node. Toxin Expression Highest in terminal Lower in blooms (pollen) Behavior, ballooning

CEW Scouting Examine top 12 inches or top 1/3 of plants. “dig” in bud open all squares Also examine: one bloom one bloom-tagged boll one boll If plant damaged: search whole plant Record number of eggs and small and large larvae per 100 plants.

Conservation Biological Control Tobacco Budworm and Bollworm Primary Pests

Stink Bug Feeding Feeds primarily on fruiting structures and meristematic tissues (seed and surrounding tissues in cotton bolls). Physical destruction of seed (lint production reduced). Introduces or allows entry (wounds) of pathogens and decay organisms. Stink bug damage common at cotton and peanut interface!

Decision Aid for Stink Bug Thresholds in Southeast Cotton

Insecticide Selection Presence Should Influence Decisions Spider Mites CEW/FAW (Leps) Aphids Whiteflies

Expert System Rules Decision Aid for Stink Bugs in Cotton Week of Bloom: treatment threshold triggers Dynamic Threshold Enter Percent Boll Injury Stink Bug Species: insecticide choice Southern Green (<25% Brown): pyrethroid Mixed (25-75% Brown): organophosphate Brown (>75% Brown): organophosphate Other Pest Species (commonly found but below established action thresholds): Weeks 2-5 of Bloom: Caterpillars: include pyrethroid Aphids: include dicrotophos, avoid acephate SLWF: use bifenthrin, avoid dicrotophos Mites: use bifenthrin, avoid acephate Weeks 6-7 of Bloom: SLWF: use bifenthrin Mites: use bifenthrin

Spider Mites Threshold: Apply when 50 percent of plants are symptomatic and populations are increasing.

Silverleaf Whitefly Management AN OUNCE OF PREVENTION IS WORTH A POUND OF CURE Cultural control Avoid late planting Conserve Benes Smooth leaf varieties Insecticides if needed

Tarnished Plant Bugs Treat when plants are retaining less than 80% of pinhead squares and plant bugs are present If bolls are being damaged, cannot be distinguished from stink bug, use Dynamic Threshold for Stink Bug. Sweep Net best for adults, pre-bloom Weeks 1-3 of Squaring: 8 per100 sweeps 3rd wk. of Squaring thru Bloom: 15 per 100 sweeps Drop Cloth (Black) best for nymphs, post-bloom Weeks 1-3 of Squaring: 1 per 6 row ft. 3rd wk. of Squaring thru Bloom: 3 per 6 row ft. Dirty Blooms: 15 percent

Tarnished Plant Bug Plant bug applications can flare spider mites. Nymphs in squares/blooms, rarely see in Georgia. Plant bug applications can flare spider mites.

Tarnished Plant Bug Notice “scar”

Retention GOAL at First Bloom Goal is to retain 80 percent of first positions when at first bloom. Maximum Yield Potential Periodically pull up plants and monitor retention of all first position squares. 1st Positions 2nd Positions 3rd Positions

Seedling Thrips Predictable insect pest. Damage includes leaf distortion, stunted plants, delays in maturity, loss of apical dominance, reduced yield potential, and in severe cases stand loss. Susceptibility to thrips feeding cotyledon > 1-leaf > 2-leaf >3-4 leaf Slow seedling growth results in increased injury symptoms and plant damage. Preventive treatments used at planting: Consistent yield response. Aldicarb (AgLogic 15G) Orthene in-furrow spray, seed treatment Imidacloprid in-furrow spray Seed Treatments (imidacloprid, thiamethoxam) Supplemental foliar spray needed when high thrips risk Jack Reed, www.ipmimages.org

1-Leaf

Average Number of Thrips Eggs by Plant Date and Leaf in Control Plots Jacobson, Auburn 2017 Average Number of Thrips Eggs by Plant Date and Leaf in Control Plots A high percentage of thrips eggs are laid on cotyledons. Just means, going to take more time to sort out egg data because there are limited number of dates with some of these leaves. Plant Date 1 Plant Date 2 Plant Date 3 Plant Date 4 Plant Date 5 Plant Date 6

CORE Thrips Trials Georgia 2016 County On-farm Research and Education trials 59 fields in 21 counties

Adult thrips per Plant (1-leaf cotton) Georgia CORE Thrips 2016

Percent Biomass Response (28 DAP) to Orthene at 1st Leaf Georgia CORE Thrips 2016

Thrips per Plant (1-leaf cotton) Georgia CORE Thrips 2016 Thrips infestations 2.5X in high risk fields vs low risk fields Fields exceeding threshold at 1-leaf: High Risk: 73 percent Low Risk: 27 percent 90 percent of fields had immature thrips present at 1-leaf Thrips per Plant (1-leaf cotton) Georgia CORE Thrips 2016 planted prior to May 10 conventional tillage planted on or after May 10 and/or reduced tillage

Management of Thrips on Cotton Relative risk of thrips injury over planting dates can be projected using rainfall and temperature to predict overlap of thrips dispersal and cotton susceptibility Cotton Thrips Injury Projector Risk by Planting Date Timeline (Chappell & Kennedy) Neonicotinoid seed treatments prevent larval feeding damage for 2-3 weeks

Cotton Thrips Infestation Projector TIP TIPs model predicted earlier thrips dispersal in 2016 vs 2015

Thrips Infestations by Calendar Date (untreated plots) 2015 & 2016 Peak 12 days earlier in 2016 vs 2015

Questions? Needs?