EFFICACY OF EAR TAGS FOR HORN FLY CONTROL IN TEXAS Ben Walker Cooperator Barry Watson Cooperator

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1 EFFICACY OF EAR TAGS FOR HORN FLY CONTROL IN TEXAS Ben Walker Cooperator Barry Watson Cooperator Ryan Collett, Extension Agent- AG/NR, Hill County Summary Horn flies are one of the most important pests to the livestock industry. Controlling horn flies is a must in the United States and can be very time consuming and costly. Horn fly adults are blood feeders that consume between 3 4 blood meals per day. The adults remain in constant contact with cattle until oviposition, therefore providing control opportunities. Lack of adequate horn fly control can lead to weight loss and eventually economic loss. Objectives Record horn fly numbers during the 213 fly season in east Texas (May October) by making weekly fly counts of cattle tagged with different types of ear tags (Patriot). Compare products to determine which is the most effective at controlling horn fly densities. Methods The study was conducted from April 25, 213 thru October 25, 213. All cattle within a herd were tagged with a designated ear tag, Patriot (organophosphate). Two ear tags were used on all cows (in compliance with the label). A control herd of cattle were selected for fly number comparison counts. Fly counts were to be conducted weekly from one side of 1 randomly selected cattle in each group (tagged and control). A digital camera was used to make these counts No other products were used for fly control during the experimental time period on tagged cattle. 93

2 Products were used for fly control during the experimental time period on the control herd if horn fly numbers began to reach above economic impact numbers (>/cow). Data & Results Control Week 1 Week 11 Week 12 Week 13 Week 14 Week 15 Week 16 Week 17 Week 18 Week 19 Week 2 Week 21 7/5/213 7/12/213 7/19/213 7/26/213 8/2/213 8/9/213 8/16/213 8/23/213 8/3/213 9/6/213 9/13/213 9/2/ Patriot Week 1 Week 11 Week 12 Week 13 Week 14 Week 15 Week 16 Week 17 Week 18 Week 19 Week 2 Week 21 Week 22 Week 23 Week 24 7/5/213 7/12/213 7/19/213 7/26/213 8/2/213 8/9/213 8/16/213 8/23/213 8/3/213 9/6/213 9/13/213 9/2/213 9/27/ /11/

3 7 Horn Fly Numbers Present per Side on Texas Cattle in Anderson Control Anderson XP82 Anderson Corathon Archer Control Archer Patriot Bowie Control Bowie Corathon Bowie GardStar Bowie IGR Childress Control Childress XP82 Delta Control Delta Warrior Houston Control Houston Python Houston XP82 Houston Patriot Panola Control Panola Patriot Panola GardStar Rusk Control Rusk Magnum Smith Control Smith Optimizer Smith GardStar Smith XP82 Trinity Control Trinity Corathon Trinity Magnum Tyler Control Tyler Warrior Upshur Control Upshur Optimizer Upshur Magnum 95

4 35 3 Horn Fly Numbers Present per Side on Texas Cattle in Control Organophosphate Pyrethroid XP82 IGR 35 3 Horn Fly Numbers Present per Side on Texas Cattle in Control XP82 Corathon Patriot GardStar Warrior Magnum Optimizer IGR Python 96

5 Average Weekly Horn Fly Numbers per side in Hill County Control Patriot 12 Percentage of Horn Flies Controlled Throughout the Treatment Period in Hill County with Patriot tags

6 Percentage of Horn Flies Controlled per County XP 82 Corathon Patriot Corathon GardStar XP82 Warrior Python XP 82 Patriot GardStar Magnum Optimizer Gardstar Spray Corathon Magnum Warrior Optimizer Magnum Anderson Archer Bowie ChildressDelta Houston Panola Rusk Smith Trinity Tyler Upshur Average Percentage of Control of Horn Flies with Ear Tags XP 82 Python Corathon Optimizer Patriot Warrior Magnum GardStar 98

7 Conclusion This is the fourth year for the ear tag efficacy testing demonstrations and with the variable results received over the years; analysis cannot be made between the years just yet. Some counties are showing optimal results with several of the ear tags but then other counties have very little efficacy when using the same ear tags. This year there were a few producers that were not pleased with the results they were getting within the first few weeks of the study period and unapproved treatments were started. This affects the overall data and any possible trends occurring with the ear tag insecticide products. The horn fly lifecycle occurs in direct contact with cattle, adults utilize cattle for food and drink (blood) and the eggs are laid in fresh manure which is always moist despite the amount of rain. Horn fly larvae are capable of increasing developmental time when needed and can grow from egg to adult in 7 days when temperatures are above 85 F. Even if horn fly numbers are similar during a wet year when compared to a drought year, it is typically harder to control the number of horn flies with insecticides when there is rain. In instances where ear tags were put in after a horn fly population has already developed, it will take several weeks before the insecticide tags impact the population numbers. The data tabulated for all counties in Texas partaking in the demonstration this year (Anderson, Archer, Bowie, Childress, Dickens, Hill, Houston, Palo Pinto, Panola, Rusk, Shelby, Smith, Trinity, Tyler, and Upshur) show similar horn fly control achieved with all the insecticide ear tags used, organophosphates, pyrethroids and abamectin products, with the pyrethroids losing effectiveness first. On average, all three insecticide classes were able to achieve horn fly numbers below 72 per side. The best results were achieved from week 5 to week 15, but overall the fly numbers were fairly low and controlled. At about week 19 the populations start to increase and continue to until the end of the study period. There were some fluctuations during this time period but the horn fly numbers did not reach above threshold levels. The horn fly levels stayed below per side for the organophosphate, abamectin and IGR treated cattle throughout the duration of the fly counting season on an overall basis and until week 23 for the pyrethroid tags. The control horn fly numbers averaged between 65 and 283 per side but some counties experienced much higher numbers (66) throughout the fly season. There was about 1 weeks of horn fly counts that were able to be analyzed in Hill County from June to October 213. The Patriot tags was used and found to be an effective and exceptional means of controlling horn flies on cattle in Hill County. Overall the percentage of 99

8 control was from 9% - 98%. The Patriot fly numbers on average remained below 7 horn flies per side while the control average ranged from 113 to 4 per side. When compared to last year s data, the results were similar but the Patriot tags were more consistent. The data this year was more complete and able to give a better perspective on the effectiveness of using organophosphate insecticides ear tags. Acknowledgments Appreciation is extended to Ben Walker and Barry Watson for offering their time, land, and cattle for these fly tag demonstrations.