{"id":784,"date":"2025-06-02T09:08:53","date_gmt":"2025-06-02T13:08:53","guid":{"rendered":"https:\/\/site.extension.uga.edu\/evansag\/?p=784"},"modified":"2025-06-02T09:08:53","modified_gmt":"2025-06-02T13:08:53","slug":"managing-flies-on-cattle-in-southeast-georgia","status":"publish","type":"post","link":"https:\/\/site.extension.uga.edu\/evansag\/2025\/06\/managing-flies-on-cattle-in-southeast-georgia\/","title":{"rendered":"Managing Flies on Cattle in Southeast Georgia"},"content":{"rendered":"\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"532\" src=\"https:\/\/site.extension.uga.edu\/evansag\/files\/2025\/05\/image-3-1024x532.png\" alt=\"\" class=\"wp-image-785\" srcset=\"https:\/\/site.extension.uga.edu\/evansag\/files\/2025\/05\/image-3-1024x532.png 1024w, https:\/\/site.extension.uga.edu\/evansag\/files\/2025\/05\/image-3-300x156.png 300w, https:\/\/site.extension.uga.edu\/evansag\/files\/2025\/05\/image-3-768x399.png 768w, https:\/\/site.extension.uga.edu\/evansag\/files\/2025\/05\/image-3-1536x799.png 1536w, https:\/\/site.extension.uga.edu\/evansag\/files\/2025\/05\/image-3.png 1800w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Horn fly infestations can deliver hundreds of painful bites to affected cattle. (Photo courtesy of the OSU Department of Entomology and Plant Pathology)<\/figcaption><\/figure>\n\n\n\n<p>Summer heat brings more than just pasture growth\u2014it also kicks fly season into high gear. For cattle producers in Southeast Georgia, flies can mean lost performance and rising health costs. Horn flies, in particular, are aggressive pests that feed on cattle 20\u201330 times a day. Left untreated, a single cow can carry up to 1,000 flies. This constant irritation leads to reduced feed efficiency, lower weight gains, and greater disease risk. For nursing calves, disrupted feeding can also mean slowed growth.<\/p>\n\n\n\n<p>Controlling flies takes a well-rounded strategy. Cultural practices like pasture rotation and manure management can limit breeding sites. Mechanical tools like back rubbers and dust bags offer hands-free protection, while chemical options\u2014sprays, pour-ons, and insecticidal ear tags\u2014provide immediate relief.<\/p>\n\n\n\n<p>One of the most effective long-term tools is the use of <strong>feed-through insect growth regulators (IGRs)<\/strong>. Products containing (S)-methoprene, like Altosid\u00ae, pass through the animal and into the manure, where they stop horn fly larvae from developing. Since horn flies lay eggs only in fresh manure, IGRs help break the life cycle at its source.<\/p>\n\n\n\n<p>IGRs work best when started early\u2014about 30 days before flies emerge\u2014and used consistently through the season. Because they don\u2019t kill adult flies, it\u2019s smart to pair them with early-season chemical treatments to reduce existing populations.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Common Chemical Control Options for Adult Flies<\/strong><\/h3>\n\n\n\n<p>To effectively manage resistance and extend product efficacy, rotate between <strong>different classes of insecticides<\/strong>. Here are the main groups used for cattle fly control:<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\" \/>\n\n\n\n<h4 class=\"wp-block-heading\">\ud83d\udfe6 <strong>Pyrethroid-Based Products<\/strong><\/h4>\n\n\n\n<p><em>(Fast knockdown, short residual \u2013 resistance common in some regions)<\/em><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Pour-Ons:<\/strong>\n<ul class=\"wp-block-list\">\n<li><em>CyLence\u00ae<\/em> (cyfluthrin)<\/li>\n\n\n\n<li><em>Ultra Boss\u00ae<\/em> (permethrin + piperonyl butoxide)<\/li>\n\n\n\n<li><em>StandGuard\u00ae<\/em> (zeta-cypermethrin)<\/li>\n\n\n\n<li><em>Clean-Up\u2122 II<\/em> (permethrin + diflubenzuron IGR)<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Sprays:<\/strong>\n<ul class=\"wp-block-list\">\n<li><em>Permectrin II\u00ae<\/em> (permethrin)<\/li>\n\n\n\n<li><em>Ectiban\u00ae<\/em><\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Ear Tags:<\/strong>\n<ul class=\"wp-block-list\">\n<li><em>Python\u00ae<\/em>, <em>Warrior\u2122<\/em>, <em>Cylence\u00ae<\/em><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\" \/>\n\n\n\n<h4 class=\"wp-block-heading\">\ud83d\udfe7 <strong>Organophosphate-Based Products<\/strong><\/h4>\n\n\n\n<p><em>(Longer residual, slower knockdown \u2013 effective against pyrethroid-resistant flies)<\/em><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Pour-Ons and Dusts:<\/strong>\n<ul class=\"wp-block-list\">\n<li><em>Co-Ral\u00ae<\/em> (coumaphos)<\/li>\n\n\n\n<li><em>DeLice\u00ae<\/em> (phosmet)<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Ear Tags:<\/strong>\n<ul class=\"wp-block-list\">\n<li><em>Corathon\u00ae<\/em> (coumaphos + cyfluthrin \u2013 dual mode)<\/li>\n\n\n\n<li><em>Ethion\u00ae<\/em> tags<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\" \/>\n\n\n\n<h4 class=\"wp-block-heading\">\ud83d\udfe9 <strong>Macrocyclic Lactones (Endectocides)<\/strong><\/h4>\n\n\n\n<p><em>(Internal parasite control + moderate fly suppression)<\/em><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Pour-Ons:<\/strong>\n<ul class=\"wp-block-list\">\n<li><em>Ivomec\u00ae Pour-On<\/em> (ivermectin)<\/li>\n\n\n\n<li><em>Dectomax\u00ae<\/em> (doramectin)<\/li>\n\n\n\n<li><em>Eprinex\u00ae<\/em> (eprinomectin \u2013 zero milk withdrawal)<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p>These are <strong>systemic treatments<\/strong>, absorbed into the bloodstream and excreted through the skin and feces, providing some reduction in <strong>horn fly numbers<\/strong>\u2014though not a stand-alone solution for heavy infestations. They also help manage <strong>lice, mites<\/strong>, and <strong>grubs<\/strong>.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>\u26a0\ufe0f <strong>Important:<\/strong> Overuse of ivermectin-type products can contribute to parasite resistance. Use judiciously and rotate with other fly control methods for best results.<\/p>\n<\/blockquote>\n\n\n\n<p>Flies aren\u2019t just a nuisance\u2014they\u2019re a costly threat to cattle health and productivity. A sound fly control plan, especially one built around consistent IGR use, can help keep your herd comfortable and on track. For help building a strategy that fits your operation, reach out to your local UGA Extension office.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong> <\/strong>Cited Sources <\/h3>\n\n\n\n<p>University of Georgia Integrated Pest Management. (2021). <em>Cattle Horn Fly Management Guide<\/em>. Retrieved from <a class=\"\" href=\"https:\/\/ipm.uga.edu\/files\/2021\/08\/Cattle-Horn-Fly.pdf\">https:\/\/ipm.uga.edu\/files\/2021\/08\/Cattle-Horn-Fly.pdf<\/a><\/p>\n\n\n\n<p>Townsend, L. (n.d.). <em>Horn Flies on Cattle (ENTFACT-504)<\/em>. University of Kentucky Entomology. Retrieved from <a>https:\/\/entomology.ca.uky.edu\/ef504<\/a><\/p>\n\n\n\n<p>University of Georgia Extension. (2024). <em>Georgia Pest Management Handbook: Livestock and Forages \u2013 Special Bulletin 28<\/em>. Retrieved from <a>https:\/\/extension.uga.edu\/publications\/detail.html?number=SB28<\/a><\/p>\n\n\n\n<p>Texas A&amp;M AgriLife Extension. (n.d.). <em>External Parasites on Beef Cattle<\/em>. Retrieved from <a>https:\/\/agrilifeextension.tamu.edu\/library\/wildlife-nature\/external-parasites-on-beef-cattle\/<\/a><\/p>\n\n\n\n<p>Oklahoma State University Extension. (n.d.). <em>External Parasite Control for Cattle (ANSI-5032)<\/em>. Retrieved from <a>https:\/\/extension.okstate.edu\/fact-sheets\/external-parasite-control-for-cattle.html<\/a><\/p>\n\n\n\n<p>Wellmark International. (n.d.). <em>Altosid\u00ae Insect Growth Regulator for Horn Fly Control<\/em>. Retrieved from <a class=\"\" href=\"https:\/\/www.centralflycontrol.com\">https:\/\/www.centralflycontrol.com<\/a><\/p>\n\n\n\n<p>Product Labels: Bayer, Merck, Elanco Animal Health. (n.d.). <em>Livestock Fly Control Product Guides and Specimen Labels<\/em>.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><em>CyLence\u00ae, Ultra Boss\u00ae, StandGuard\u00ae, Ivomec\u00ae, Dectomax\u00ae, Eprinex\u00ae, Corathon\u00ae<\/em><\/li>\n<\/ul>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Summer heat brings more than just pasture growth\u2014it also kicks fly season into high gear. For cattle producers in Southeast Georgia, flies can mean lost performance and rising health costs. Horn flies, in particular, are aggressive pests that feed on cattle 20\u201330 times a day. Left untreated, a single cow can carry up to 1,000 [&hellip;]<\/p>\n","protected":false},"author":324,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12],"tags":[],"class_list":["post-784","post","type-post","status-publish","format-standard","hentry","category-cattle-forages"],"_links":{"self":[{"href":"https:\/\/site.extension.uga.edu\/evansag\/wp-json\/wp\/v2\/posts\/784","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/site.extension.uga.edu\/evansag\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/site.extension.uga.edu\/evansag\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/site.extension.uga.edu\/evansag\/wp-json\/wp\/v2\/users\/324"}],"replies":[{"embeddable":true,"href":"https:\/\/site.extension.uga.edu\/evansag\/wp-json\/wp\/v2\/comments?post=784"}],"version-history":[{"count":2,"href":"https:\/\/site.extension.uga.edu\/evansag\/wp-json\/wp\/v2\/posts\/784\/revisions"}],"predecessor-version":[{"id":787,"href":"https:\/\/site.extension.uga.edu\/evansag\/wp-json\/wp\/v2\/posts\/784\/revisions\/787"}],"wp:attachment":[{"href":"https:\/\/site.extension.uga.edu\/evansag\/wp-json\/wp\/v2\/media?parent=784"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/site.extension.uga.edu\/evansag\/wp-json\/wp\/v2\/categories?post=784"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/site.extension.uga.edu\/evansag\/wp-json\/wp\/v2\/tags?post=784"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}