E-570 8/12 Managing External Parasites of Texas Cattle Sonja L Swiger Assistant Professor and Extension Entomologist, The Texas A&M System Contents Integrated Pest Management .........................................................................3 Cultural control ................................................................................................................................3 Biological control .............................................................................................................................3 Chemical control ..............................................................................................................................3 Safety Tips for Using Pesticides .......................................................................3 Livestock Pests ..............................................................................................4 Horn fly ............................................................................................................................................4 Managing pyrethroid- and organophosphate-resistant horn flies ..............................................5 Treatment options.....................................................................................................................5 House fly ..........................................................................................................................................5 Stable fly ..........................................................................................................................................5 Screwworm fly .................................................................................................................................6 Blow fly ............................................................................................................................................6 Cattle grub (Heel fly) .........................................................................................................................6 Other biting flies ...............................................................................................................................7 Horse fly and Deer fly ................................................................................................................7 Mosquito ..................................................................................................................................7 Black fly ....................................................................................................................................7 Lice ................................................................................................................................................8 Mites ................................................................................................................................................8 Ticks ................................................................................................................................................9 Insecticide Application Methods ...................................................................11 Sprays ............................................................................................................................................11 Dips ..............................................................................................................................................11 Pour-ons ........................................................................................................................................11 Spot-ons ........................................................................................................................................11 Dusts ..............................................................................................................................................11 Injectables ......................................................................................................................................11 Feed and mineral pesticide additives ...............................................................................................11 Insecticide-impregnated ear tags ....................................................................................................12 Baits ..............................................................................................................................................12 Boluses ..........................................................................................................................................12 Dilution Chart for Mixing Sprays or Dips.........................................................13 Formulas and Examples ...............................................................................13 Pesticide Suggestions ..................................................................................14 Beef cattle and non-lactating dairy cattle .......................................................................................14 Lactating dairy cattle......................................................................................................................28 Premises (Inside or outside of animal quarters) ...............................................................................35 The Texas dairy and beef cattle industry is a $12 Biological control billion industry and controlling external parasites is You must identify insect populations accurately an important part of avoiding financial losses. to make pest control decisions and avoid overusing External parasites, commonly called ectoparasites, pesticides. Some insects are harmless to humans cost livestock owners billions of dollars each year. and animals and can be used to control pest insects Untreated, these parasites make animals suffer and through predation: lose weight. Parasites also lower the quality of animal ▶ Fire ants prey on any available larvae. products by: ▶ Black dump fly larvae feed on house fly larvae ▶ feeding on their hides and hair developing in the same manure. ▶ reducing meat and milk production by suck- ▶ Small fish and immature dragonflies, damsel- ing their blood flies, and mayflies feed on mosquito larvae. ▶ transmitting diseases Beneficial insects can also control pest popula- ▶ causing cattle to lose energy tions through competition: ▶ Soldier fly maggots eat more manure than Integrated pest management horn fly or house fly maggots, leaving com- Efficient pest management requires that cattle op- petitors short of food and unable to complete erators understand the three components of integrated development. pest management (IPM) and how they work together. ▶ Dung beetles remove manure to house their IPM uses cultural, biological, and chemical control larvae. This causes the pats to dry faster and methods to more effectively suppress insect pests. become unsuitable for fly development. ▶ Parasitic wasps lay eggs inside immature horn Cultural control flies, house flies, and stable flies. The wasp larva then eats the immature flies. Cultural control focuses on preventing new infes- Though wasps can be used to supplement sanita- tations by minimizing conditions that support insect tion, parasitic wasps probably will not control pests breeding. adequately in an environment that promotes breed- The best way to prevent initial infestations is to ing. check and treat new cattle for lice, ticks, or mites For more information, see http://www.ca.uky.edu/ before adding them to existing herds. entomology/entfacts/ef502.asp. Poor sanitary conditions in and around barns/ operations encourage insect reproduction. The most effective way to control insect and mite populations, Chemical control minimize breeding conditions: Pesticides should be used only when preventive ▶ Remove and dispose of carcasses quickly. methods are not effective or available. Use chemical ▶ Clean up and dispose of manure and spilled control methods only when pest activity is at its high- feed—especially if they are wet. est. ▶ Keep drainage ditches clear by cleaning out weeds. Safety tips for using pesticides ▶ Remove straw or hay that has been defecated ▶ Follow all directions and safety precautions and urinated on. precisely. Never deviate from pesticide label ▶ Clean and dress all wounds on cattle to ex- recommendations. clude blowflies and prevent infection. ▶ Record every pesticide application; include the One pound of moist manure or wasted feed can common name, trade name, formulation, di- support the production of up to 1,000 house flies— lution, application rate, and date of treatment. but larvae cannot survive on manure with less than ▶ Use a facemask or respirator and protective 30 percent moisture. Remove manure from barns at clothing during spraying. Avoid breathing least twice a week and spread it thin on pastures. Do spray mist or dust. Follow label recommenda- not pile manure or leave it in clumps. Rotate the pas- tions regarding personal protective equipment. tures to allow manure to dry out and decompose. 3 ▶ If you spill pesticides on your skin or clothes, react by licking their backs, twitching their flanks, wash them thoroughly with soap and wa- switching their tails, and kicking at their bellies with ter, and change clothes. Wash contaminated their hind legs. When flies exceed 250 per side, cattle clothing separately from household laundry. will lose 15 to 50 percent of their weight. ▶ Do not eat, drink, or smoke when handling Horn flies are the same color as house flies and pesticides.