Corn Rootworms Presented Significant Challenges in 2004: Product Performance Issues Linger Michael E. Gray and Kevin L. Steffey Department of Crop Sciences University of Illinois

Corn Rootworm Insecticide Efficacy Trials, 2004 Locations: DeKalb, Monmouth, and Urbana Planting dates: April 28, 27, and 19, respectively Hybrid: Golden Harvest (H-8588 RW) and isoline (Golden Harvest H-8799) Root evaluations: July 21, July 15, and July 10 Plots planted within a trap crop system (late-planted corn interplanted with pumpkins) Liquids applied in 6-inch bands over rows, 5 gpa, 47 psi Spring tines were mounted behind firming wheels of planter Planting population – 30,000 seeds per acre Golden Harvest (H-8588 RW) treated with Poncho roots per treatment were evaluated for larval injury

Corn Rootworm Control Trial Urbana, Illinois, 2004 Average Root Rating Planting date – April 19 Rainfall: May – 4.4”, June – 3.8”, July – 5.7”, Aug. – 3.6” July 10, 2004

Corn Rootworm Control Trial Urbana, Illinois, 2004 Average % Consistency 0

Corn Rootworm Control Trial Urbana, Illinois, 2004 Average % Lodging Planting date – April 19 Rainfall: May – 4.4”, June – 3.8”, July – 5.7”, Aug. – 3.6” Sept. 28, 2004

Corn Rootworm Control Trial Urbana, Illinois, 2004 Yield – Bushels per Acre

YieldGard RW, DeKalb, September 3, 2004

Corn Rootworm Control Trial DeKalb, Illinois, 2004 Average Root Rating Planting date – April 28 Rainfall: May – 9.5”, June – 3.1”, July – 2.1”, Aug. – 3.3” July 21, 2004

Corn Rootworm Control Trial DeKalb, Illinois, 2004 Average % Consistency 0 0 0

Corn Rootworm Control Trial DeKalb, Illinois, 2004 Average % Lodging Planting date – April 28 Rainfall: May – 9.5”, June – 3.1”, July – 2.1”, Aug. – 3.3”

Corn Rootworm Control Trial DeKalb, Illinois, 2004 Yield – Bushels per Acre

Conclusions … The insecticidal seed treatments (Poncho 1250 and Cruiser) did not provide adequate root protection in our insecticide efficacy trials (DeKalb, Monmouth, Urbana) in Under heavy pressure, Poncho 1250 and Cruiser may be poor product choices for a refuge when using a transgenic insecticidal hybrid for corn rootworm control. The granular soil insecticides (exception Empower 2 ) generally provided acceptable levels of root protection in our Illinois’ trials. The YieldGard Rootworm hybrid provided less than satisfactory root protection in the Urbana experiment.

University of Illinois Web sites:

2004 Corn Rootworm Efficacy Results For Indiana Larry Bledsoe Purdue University

Root Rating Performance 1, 2004 Seed-Applied Location Best Rating 2 Cruiser Poncho 1250 Check Lafayette, IN 1.50 ygr Wanatah, IN 2.20 frt Columbia City, IN 1.60 ygr Dekalb, IL 2.35 ygr Monmouth, IL 1.80 ygr Urbana, IL 2.45 frc Root damage rating scale: 1=None or minor feeding scars, 6=severe injury. 3.0 or greater=plants likely predisposed to a significant loss. 2 The “Best Rating” is the least amount of rootworm damage for any product in the plot.

Root Rating Performance 1, 2004 Liquid Location Best Rating 2 Capture TB Regent IF Lorsban 4E Check Lafayette, IN 1.50 ygr Wanatah, IN 2.20 frt Columbia City, IN 1.60 ygr Dekalb, IL 2.35 ygr Monmouth, IL 1.80 ygr Urbana, IL 2.45 frc Root damage rating scale: 1=None or minor feeding scars, 6=severe injury. 3.0 or greater=plants likely predisposed to a significant loss. 2 The “Best Rating” is the least amount of rootworm damage for any product in the plot.

Root Rating Performance 1,2, 2004 Granular Location Best Rating 3 Aztec 2.1G Counter CR Empower Force 3G Fortress 2.5G Lorsban 15G Check Lafayette, IN1.50 ygr Wanatah, IN2.20 frt Columbia City, IN 1.60 ygr Dekalb, IL2.35 ygr Monmouth, IL1.80 ygr Urbana, IL2.45 frc Root damage rating scale: 1=None or minor feeding scars, 6=severe injury. 3.0 or greater=plants likely predisposed to a significant loss. 2 All products applied in T-band except for Fortress 2.5G which was placed in-furrow. 3 The “Best Rating” is the least amount of rootworm damage for any product in the plot.

Root Rating Performance 1, 2004 TransgenicGranular Location Best Rating 2 YieldGard RW Aztec 2.1G Force 3G Check Lafayette, IN 1.50 ygr Wanatah, IN 2.20 frt Columbia City, IN 1.60 ygr Dekalb, IL 2.35 ygr Monmouth, IL 1.80 ygr Urbana, IL 2.45 frc Root damage rating scale: 1=None or minor feeding scars, 6=severe injury. 3.0 or greater=plants likely predisposed to a significant loss. 2 The “Best Rating” is the least amount of rootworm damage for any product in the plot.

Soil Insecticide Consistency* ClassOrganophosphatesPyrethroidsFiproles Nico- tinoids Fortress 5G Lorsban 15G Aztec 2.1G Counter CR Capture 2E Force 3G Regent 4SC Poncho 1250 Band Applic. Root rating % consistency n/a Infurrow Root rating % consistency n/a Seed Applied Root rating % consistency n/a *% of root masses where damage rating was less than 3.0 when the untreated equaled or exceeded 3.0.

Corn Rootworm Control Efficacy Trials Iowa Dr. Jon Tollefson Professor of Entomology Iowa State University

Iowa 1  6 Root- Rating Index 1.No or minor feeding damage 2.Feeding injury evident, but no roots eaten back to within 1½ in. of plant 3.Several roots pruned to within 1½ in. of plant, but never equivalent of entire node 4.One node eaten back to with 1½ in. of plant 5.Two nodes eaten 6.Three nodes eaten

Node-Injury Scale X. YY Percentage of a node eaten Number of full nodes eaten

Node-Injury Scale 0.00No feeding damage 1.00One node of roots, or equivalent of a node, eaten back to within 2” of stalk 2.00Two nodes eaten 3.00Three or more nodes eaten Damage between complete nodes is scored as percent: 0.25 = ¼ node eaten 1.50 = 1½ nodes eaten

Rootworm Efficacy, Crawfordsville, 2004 ProductRatePlacementInjuryConsistency YieldGard RW---GM0.02 a100 a Aztec 2.1G0.14F0.16 ab100 a Fortress 5G0.185F-sb0.18 ab98 a Force 3G0.12F0.18 ab98 a Aztec 2.1G0.14TB0.22 ab88 ab Force 3G0.12TB-sb0.23 ab93 ab Force 3G0.12TB0.24 ab85 ab Fortress 2.5G0.185F0.26 ab90 ab Aztec 4.67G0.14TB-sb0.26 ab85 ab Lorsban 15G1.2TB0.28 ab78 ab Aztec 4.67G0.14F-sb0.33 bc73 ab Capture 2EC0.09TB0.38 bcd65 abc Capture 2EC0.09F0.39 bcd58 bcd Empower2-1.15g0.092TB0.58 cde20 cde Poncho 600FS1.25 mgST0.60 cde32 cde Regent 4SC0.12F-m0.64 de30 cde Empower2-1.15g0.092F0.72 e23 de Cruiser 5FS1.25 mgST0.98 f10 e Check f0 e

Rootworm Efficacy, Crawfordsville, 2004 ProductRatePlacementInjury% Lodging YieldGard RW---GM0.02 a3 ab Aztec 2.1G0.14F0.16 ab0 a Fortress 5G0.185F-sb0.18 ab0 a Force 3G0.12F0.18 ab0 a Aztec 2.1G0.14TB0.22 ab0 ab Force 3G0.12TB-sb0.23 ab0 ab Force 3G0.12TB0.24 ab0 ab Fortress 2.5G0.185F0.26 ab1 ab Aztec 4.67G0.14TB-sb0.26 ab0 a Lorsban 15G1.2TB0.28 ab0 a Aztec 4.67G0.14F-sb0.33 bc3 ab Capture 2EC0.09TB0.38 bcd1 a Capture 2EC0.09F0.39 bcd2 ab Empower2-1.15g0.092TB0.58 cde6 ab Poncho 600FS1.25 mgST0.60 cde9 ab Regent 4SC0.12F-m0.64 de12 ab Empower2-1.15g0.092F0.72 e17 b Cruiser 5FS1.25 mgST0.98 f36 c Check f39 c

Rootworm Efficacy, Crawfordsville, 2004 ProductRatePlacementInjuryBushels/acre YieldGard RW---GM0.02 a175 a Aztec 2.1G0.14F0.16 ab185 a Fortress 5G0.185F-sb0.18 ab175 a Force 3G0.12F0.18 ab184 a Aztec 2.1G0.14TB0.22 ab175 a Force 3G0.12TB-sb0.23 ab170 abc Force 3G0.12TB0.24 ab185 a Fortress 2.5G0.185F0.26 ab173 ab Aztec 4.67G0.14TB-sb0.26 ab170 abc Lorsban 15G1.2TB0.28 ab187 a Aztec 4.67G0.14F-sb0.33 bc174 ab Capture 2EC0.09TB0.38 bcd171 abc Capture 2EC0.09F0.39 bcd180 ab Empower2-1.15g0.092TB0.58 cde178 a Poncho 600FS1.25 mgST0.60 cde176 a Regent 4SC0.12F-m0.64 de170 abc Empower2-1.15g0.092F0.72 e171 abc Cruiser 5FS1.25 mgST0.98 f154 bc Check f151 c

Rootworm Efficacy, Nashua, 2004 ProductRatePlacementInjuryConsistency YieldGard RW---GM0.02 a100 a Aztec 2.1G0.14TB0.23 ab83 ab Force 3G0.12TB0.27 ab70 abc Aztec 4.67G0.14TB-sb0.29 ab70 abc Force 3G0.12F0.34 ab70 abc Aztec 4.67G0.14F-sb0.41 ab50 abcd Force 3G0.12TB-sb0.43 ab47 abcd Aztec 2.1G0.14F0.44 ab50 abcd Capture 2EC0.09F0.45 ab43 abcd Capture 2EC0.09TB0.57 ab43 abcd Regent 4SC0.12F-m0.61 bc53 abcd Fortress 2.5G0.185F0.72 abc40 abc Empower2-1.15g0.092F0.73 abc27 bcd Poncho 600FS1.25 mgST0.77 abc20 cd Empower2-1.15g0.092TB0.80 bc47 bcd Lorsban 15G1.2TB1.38 cd7 d Fortress 5G0.185F-sb1.54 d8 d Cruiser 5FS1.25 mgST1.66 d10 d Check d3 d

Rootworm Efficacy, Nashua, 2004 ProductRatePlacementInjury% Lodging YieldGard RW---GM0.02 a0 a Aztec 2.1G0.14TB0.23 ab0 a Force 3G0.12TB0.27 ab0 a Aztec 4.67G0.14TB-sb0.29 ab0 a Force 3G0.12F0.34 ab0 a Aztec 4.67G0.14F-sb0.41 ab0 a Force 3G0.12TB-sb0.43 ab0 a Aztec 2.1G0.14F0.44 ab0 a Capture 2EC0.09F0.45 ab0 a Capture 2EC0.09TB0.57 ab0 a Regent 4SC0.12F-m0.61 bc7 ab Fortress 2.5G0.185F0.72 abc1 a Empower2-1.15g0.092F0.73 abc0 a Poncho 600FS1.25 mgST0.77 abc6 ab Empower2-1.15g0.092TB0.80 bc4 a Lorsban 15G1.2TB1.38 cd6 ab Fortress 5G0.185F-sb1.54 d11 ab Cruiser 5FS1.25 mgST1.66 d18 bc Check d29 c

Rootworm Efficacy, Nashua, 2004 ProductRatePlacementInjuryBushels/acre YieldGard RW---GM0.02 a217 a Aztec 2.1G0.14TB0.23 ab199 ab Force 3G0.12TB0.27 ab202 ab Aztec 4.67G0.14TB-sb0.29 ab193 ab Force 3G0.12F0.34 ab209 ab Aztec 4.67G0.14F-sb0.41 ab203 ab Force 3G0.12TB-sb0.43 ab205 ab Aztec 2.1G0.14F0.44 ab190 ab Capture 2EC0.09F0.45 ab205 ab Capture 2EC0.09TB0.57 ab205 ab Regent 4SC0.12F-m0.61 bc202 ab Fortress 2.5G0.185F0.72 abc191 ab Empower2-1.15g0.092F0.73 abc206 ab Poncho 600FS1.25 mgST0.77 abc209 ab Empower2-1.15g0.092TB0.80 bc190 ab Lorsban 15G1.2TB1.38 cd201 ab Fortress 5G0.185F-sb1.54 d182 b Cruiser 5FS1.25 mgST1.66 d189 ab Check d186 ab

Rootworm Efficacy, Sutherland, 2004 ProductRatePlacementInjuryConsistency YieldGard RW---GM0.00 a100 a Aztec 2.1G0.14F0.02 ab100 a Fortress 5G0.185F-sb0.02 ab100 a Fortress 2.5G0.185F0.02 ab100 a Force 3G0.12TB0.02 ab100 a Force 3G0.12F0.03 ab100 a Aztec 4.67G0.14F-sb0.04 ab100 a Aztec 2.1G0.14T0.05 ab100 a Capture 2EC0.074TB0.06 ab100 a Lorsban 4E1.2TB0.07 ab100 a Lorsban 15G1.2TB0.09 ab100 a Poncho 600FS1.25 mgST0.11 ab100 a Cruiser 5FS0.092ST0.38 ab77 ab Poncho 600FS0.25 mgST0.42 ab60 ab Cruiser 5FS0.25 mgST0.45 ab70 ab Check d3 d

2-Year Summary of Rootworm Control, IA ProductPlacementInjuryConsistencyLodging Aztec 2.1GF0.24 ab82 ab0 a Aztec 2.1GTB0.33 b70 b0 a Aztec 4.67GF-sb0.29 ab74b1 a Aztec 4.67GTB-sb0.27 ab81 ab0 a Capture 2ECTB0.72 d42 de2 a CruiserST1.34 e10 fg20 b Force 3GF0.26 ab82 ab0 a Force 3GTB0.26 ab79 b0 a Fortress 2.5GF0.38 bc71b1 a Fortress 5GF-sb0.61 cd63 bc2 a Lorsban 15GTB0.70 d51cd2 a Poncho 1250ST0.84 d25 ef3 a YieldGard RWGM0.03 a98 a1 a Check f2 g26 c

Monsanto Genetically Engineered Corn, Ames, IA Product Place- ment Node Injury Consis- tency % Lodging YieldGard RW a100 a0 a Force 3G TB0.09 a95 a10 a Poncho 1250 ST1.80 b5 b58 b YieldGard CB b0 b23 b CHECK b0 b38 b

Monsanto Genetically Engineered Corn, Ames, IA Product Place- ment 1 st Gen ECB rating 2 nd Gen ECB # Tunnels cm Tunnels YieldGard RW b1.6 b6.0 b Force 3G TB2.33 b1.7 b6.4 b Poncho 1250 ST2.53 b1.8 b6.6 b YieldGard CB a0.0 a CHECK b1.2 b4.1 ab

Ostlie © 2005 Corn Rootworm Management Trials in Minnesota, Ken Ostlie Department of Entomology - University of Minnesota (612) office (612) cell

Ostlie © 2005 Basic Principles: Managing Insects 1. Farmers are engaged in risk management …balancing costs of product vs probability and magnitude of adverse outcomes. 2. Insect management traits only protect yield potential 3. All features have logistical as well as direct economic costs. 4. Predicting risk requires an investment in field- specific information (=scouting)… 5. May not be feasible, practical or cost effective.

Ostlie © 2005 Prophylactic (Insurance) Treatments Applied before pests appears Examples: u Transgenic crops (Bt rootworm) u Seed-applied insecticides (seed treatments) u Soil-applied insecticides (if decision not based on scouting) When to use an insurance treatment? u If risk (probability, severity) of problem is high u If efficacy is better, or rescue options are lacking u If treatments are difficult to time u If scouting resources are limited

Ostlie © 2005 What are the Downsides of Insurance Treatments? u Unnecessary costs u Loss of flexibility and reactivity u Reduces emphasis on scouting and field- specific farming u May sacrifice performance for convenience u Resistance development

Ostlie © 2005 Dilemma for Farmers Making management decisions for preventative treatments based on limited data! Key Insurance Questions:  How much do you need?  How much can you afford?

Ostlie © 2005 Corn Rootworm Injury

Ostlie © 2005 Corn Root Protection: Transgenics, Seed Treatments and Soil Insecticides Ostlie – Rosemount, 2003 Seed Trt.Granules Liquids Transgenic

Ostlie © 2005 Corn Root Protection: Transgenics, Seed Treatments and Soil Insecticides Ostlie & Potter – Lamberton, 2003 Seed Trt.Granules Liquids Transgenic

Ostlie © 2005 Corn Root Protection: Transgenics, Seed Treatments and Soil Insecticides Ostlie & Potter – Lamberton, 2003 Seed Trt.Granules Liquids Transgenic

Ostlie © 2005 Yield Protection: Transgenics, Seed Treatments and Soil Insecticides Ostlie & Potter – Lamberton, 2003 Seed Trt.Granules Liquids Transgenic

Ostlie © 2005 Synopsis of Corn Rootworm Management Studies: u Bt CRW consistently offers root protection better than or equal to granular insecticides. Yields are slightly higher than comparable isolines protected by soil insecticides. Further study of yield effects warranted. CRW management in refuge acres continues to be a dilemma. Yield potential of Bt CRW hybrids currently a limit to adoption. u Granular soil insecticides offer the most consistent root protection among the insecticide treatments. The performance of band vs infurrow application varies with moisture; T-bands perform worse under drought conditions. ½ and ¾ rates of Aztec, Counter and Force work as well as full rates. Fortress performs well at the higher rate labeled by AMVAC.

Ostlie © 2005 Synopsis of Corn Rootworm Management Studies: u Liquid performance varies with soil moisture from planting through pupation. Under droughty conditions performance deteriorates. u Seed treatments consistently protect only ½ - ¾ node compared to unprotected roots. Under heavy pressure, root and lodging protection were unacceptable. Yield response occasionally more than expected. Broad scale trials need to examine stand and early-season vigor contributions to yield. Importance of scouting to determine where to use seed treatments is critical.

Ostlie © 2005 What Role does Early-Season Vigor and Stand Protection Play in Yield Response? NeoNicotinoid Seed Treatment Conventional Soil Insecticide

Ostlie © 2005 What are Lodging and Yield Consequences of Seed Treatments and Transgenics? u Basic design: Factorial of 3 CRW management options (None, Force 3G, Bt CRW) with 3 rates of Poncho (None, 250 and 1250). Missing Bt CRW without Poncho. u Monitored stand, root injury, lodging and yield u Replicated in studies across the Midwest.

Ostlie © 2005 Stand Response to Corn Rootworm Protection Minnesota – 2004

Ostlie © 2005 Corn Rootworm Protection: IA Nodal Injury scale, 0-3 Minnesota

Ostlie © 2005 Lodging Response to Corn Rootworm Protection Minnesota

Ostlie © 2005 Yield Response to Corn Rootworm Protection Minnesota

Ostlie © 2005 Root and stand protection provided by CRW management options are well-understood. The big questions relate to the value of insurance treatments. What’s the frequency of payoffs vs costs? Is there anything($$) returned to your wallet? Can scouting be used to ensure value?

Rootworm Trial Results Lance J. Meinke University of Nebraska-Lincoln Trial Site: University of Nebraska Agricultural Research and Development Center, Mead, NE

2004 Corn Rootworm Soil Insecticide Experiment 2.32 f 0.24 abc 0.29 abc 0.23 abc 0.18 abc 0.17 abc 0.15 ab 0.12 ab 0.05 a RR Counter 15G (TB) 70.2Untreated 2.0 Force 3G (TB) 2.5 Aztec 2.1G (TB) 2.3 Fortress 2.5G (I) 0.0 Regent 4 SC (MT) 1.2 Aztec 3.78G (TB) 0.7 Aztec 2.1 (½ rate, TB) + Poncho 1250 (ST) 0.0 YieldGard Rootworm + Poncho 250 Percentage Lodged Insecticide

2004 Corn Rootworm Soil Insecticide Experiment 2.32 f 1.24 e 1.18 e 1.01 de 0.67 cd 0.57 bcd 0.52 abcd 0.51 abcd 0.36 abc RR Untreated 38.7 Thimet 20G (TB) 12.6 Capture 2EC (MT) 14.8 Cruiser 5 FS (ST) 2.6 Capture 2EC (TB) 0.7 Poncho 1250 (ST) 3.8 Lorsban 15G (TB) 7.6 Force 3G (TB, SB) 1.8 Lorsban 4E (TB) 5.4 Aztec 4.67G (SB) Percentage Lodged Insecticide

2004 Efficacy and Yield Experiment Treatment RR 0-3 Scale Percentage Lodging MON863 DKC Poncho a 0.0 Isoline DKC Regent 4 SC 0.62 ab 1.9 Isoline DKC Force 3G 0.85 ab 2.6 Isoline DKC Poncho bc 5.1 Isoline DKC Poncho cd 24.5 Isoline DKC Cruiser 5 FS 2.06 de 29.4 Isoline DKC e 93.5

2004 Efficacy and Yield Experiment Treatment RR 0-3 Scale Bulk Yield / Acre (bushels) MON863 DKC Poncho a a Isoline DKC Regent 4 SC 0.62 ab a Isoline DKC Force 3G 0.85 ab a Isoline DKC Poncho bc a Isoline DKC Poncho cd a Isoline DKC Cruiser 5 FS 2.06 de a Isoline DKC e b

Rootworm control efficacy Robert Wright University of Nebraska South Central Ag Lab, Clay Center

2003, Clay Center ProductPlacementRoot injury rating (0-3) Aztec 2.1GTB0.62 a Cruiser 5FSST1.14 ab Poncho 1250 ST1.30 b Untreated-2.53 c

2003, Clay Center ProductPlacementYield (bu/acre) Aztec 2.1GTB212.2 a Cruiser 5FSST210.3 a Poncho 1250 ST214.8 a Untreated b

2003, Clay Center HybridInsecticideRoot injury rating (0-3) YGRW (DKC60-12) No0.15 a Isoline (DKC60-15) Aztec 2.1G TB 0.35 ab IsolineNo0.44 b

2003, Clay Center HybridInsecticideYield (bu/acre) YG RW (DKC60-12) No237.7 a Isoline (DKC60-15) Aztec 2.1G TB ab IsolineNo b

Clay Center Summary ProductRateRR (1-6) Force 3G TB4 oz/1000 row-ft3.31 a Aztec 2.1G TB6.7 oz/1000 row-ft3.34 a Counter 20CR TB 6 oz/1000 row-ft3.60 ab Regent 4SC MT0.24 fl oz/1000 row-ft3.91 b Untreated-5.90 c

Clay Center, ProductRateRR (1-6) Force 3G TB4 oz/1000 row-ft 3.07 a Aztec 2.1G TB 6.7 oz/1000 row-ft 3.09 a Capture 2EC MT 0.3 fl oz/1000 row-ft 4.04 b Untreated-4.91 c

UNL Web sites y.htmhttp://nerec.unl.edu/ipm/entomology/entomolog y.htm