Rynaxypyr DPXE 2 Y 45 Cypermethrin Susceptibility of

Rynaxypyr™ (DPX-E 2 Y 45) & Cypermethrin: Susceptibility of a Selected Lepidopteran Cotton Pest J. H. Temple, P. L. Bommireddy, P. Marcon, S. Micinski, & B. R. Leonard

Bollworm Sampling Sites W Collection sites (2005 -2007)

Trends in Midwest: Pyrethroid Efficacy in CEW Declines: % Larval Control in Sweet Corn (Capture/Warrior; WI, MN) Year 1997 1998 1999 Mean 93 88 81 2000 2001 2002 2003 2004 2005 2006 2007 49 17 41 40 69 40 61 35 Hutchison et al. Univ. of Minn.

Objective Evaluate Bollworm Susceptibility to: 1. Cypermethrin 2. Rynaxypyr (DPX-E 2 Y 45)

Adult Vial Test 5 & 10 μg/vial Cypermethrin

Collection Sites Across LA Cotton Acreage Sampling Sites

Historical Bollworm Survival (AVT) May-Sept 1988 to 2006 May-Sep 2007* % Survival Cypermethrin 5 µg/vial * 8 collection sites, 1000 moths tested Louisiana

Annual Bollworm Survival (5 µg/vial) Percent Survival Cypermethrin

Percent Survival Annual Bollworm Survival (10 µg/vial) Cypermethrin 0%

Average Bollworm Survival (AVT) 2005 -2007 Late Season Field Collections Percent Survival Cypermethrin 5 µg/vial

TOPICAL APPLICATION

Louisiana Bollworm Topical Results Colony Winnsboro-04 Winnsboro-05 LSU Lab-06 N 160 115 240 LC 501 6. 12 3. 48 0. 20 95%CL 4. 92 -7. 76 0. 03 -0. 05 0. 04 -0. 06 Slope 2. 92± 0. 37 3. 15± 0. 41 2. 56± 0. 36 RR 7 -22 4 -12 NA Winnsboro-06 Winnsboro-07 Du. Pont Lab-07 220 190 240 3. 50 2. 80 0. 21 0. 03 -0. 05 0. 07 -0. 12 0. 05 -0. 07 2. 69± 0. 34 2. 23± 0. 28 2. 83± 0. 41 4 -12 3 -10 NA Resistance Ratios (RR) calculated from LD 50 data (0. 28 to 0. 88 µg/g larval weight) derived from Louisiana lab and field collections 1998 (Unpublished Data, J. Adamcyck and J. Gore LSU Dept. of Entomology). 1µg/g larval weight.

Summary Pyrethroid Monitoring LA BW susceptibility to pyrethroids continues to decline. Widespread concerns (Midwest, TX, Southeast) Continue monitoring program during 2008. Alternative control strategies: Transgenics and Alternative Insecticides (Rynaxypyr)

Rynaxypyr™ (DPX-E 2 Y 45) Coragen™ SC & Altacor™ WG Novel insecticide chemistry Class: Anthranilic diamides MOA: Muscle Functions Calcium Channels High toxicity to Lepidoptera at very low rates, long residual Feeding cessation, lethargy, paralysis, and death

Bollworm Colonies Rynaxypyr LSU Lab Du. Pont Lab Georgia Field North Carolina Field Virginia Field Delaware Field Louisiana Field

Diet Incorporation Methods Formulated Rynaxypyr (35 WG) dissolved in distilled water to create stock solution 100 µg/ml Nine serial dilutions created 0. 01 -1 µg/ml diet 3 rd instar larvae placed on range of treated diet doses Mortality rated at 24, 48, 72, 96 HAE Mortality analyzed using Polo-Plus Probit Analysis to create LC 50’s

Percent Mortality Diet Incorporation of Rynaxypyr LSU Lab Bollworm 0. 069 LC 50 Range ( 0. 062 -0. 086) Dose (µg/ml of diet)

Bollworm Diet Incorporation Results Colony LSU Lab Georgia North Carolina N 280 240 180 LC 501 0. 07 0. 04 0. 05 95%CL 0. 05 -0. 10 0. 03 -0. 05 0. 04 -0. 06 Slope 2. 85± 0. 31 3. 15± 0. 41 2. 56± 0. 36 Χ 2 11. 82 1. 80 3. 43 Virginia Delaware Louisiana Du. Pont Lab 240 210 240 0. 04 0. 09 0. 06 0. 04 0. 03 -0. 05 0. 07 -0. 12 0. 05 -0. 07 0. 03 -0. 05 2. 69± 0. 34 2. 23± 0. 28 2. 83± 0. 41 2. 78± 0. 35 2. 90 4. 27 3. 12 2. 69 1µg/ml diet

Lab and Field Bollworm Survival (AVT) Percent Survival Cypermethrin 5 µg/vial 0%

Lab and Field Bollworm Survival (Diet) Percent Survival Cypermethrin 5 µg/vial LC 50 values to Rynaxypyr (Diet incorporation) 0. 069 0% 0. 061

Rynaxypyr Summary Toxic at relatively low doses Activity: Contact and Ingestion All Bollworm colonies had similar LC 50’s (5 -states, 2 -Lab colonies) No Cross-resistance to pyrethroids observed

Acknowledgments Sandy Stewart, Brandi Woolam, Karla Emfinger, Trey Price, Sierra Jones, Sara Lowe, Nick Cannady, Josh Russell, and numerous other student workers at the Macon Ridge Research Station. Bollworm collections: Kathleen Heldreth, Glenn Hammes, Tom Kuhar, John Van Duyn, Bob Williams, Chris Williams, Joe Saienni, and Greg Hannig.