Controlling Stable Flies with Pour-ons
Stable flies ("biting house flies") are blood -sucking flies whose painful bites cause cattle to exhibit behaviors such as headlong flight across the corral, repeated kicking to discourage the flies, and herd bunching to avoid bites. Such activities raise the cow's temperature, expend energy, interrupt feeding, and risk injury. While stable fly activity typically is limited to early spring and late fall, severity of fly activity can result in significant production loss.
Stable flies preferentially feed on the lower portions of cattle (around the legs and belly, including the udder). They feed quickly and fly away, minimizing exposure to any insecticides applied to these areas. Additionally, insecticides applied to these body regions are rubbed off by contact with vegetation and mud, or washed off when animals are rinsed prior to milking.
Because chemical control options are so limited, source reduction, or larval breeding site elimination, are particularly critical in stable fly suppression. Stable fly larvae develop in damp plant material such as soggy hay, old wet manure, and poorly composting lawn clippings. These materials should be spread in a thin layer to dry in the sun, or dealt with in some manner that will render them unsuitable for fly breeding. Spraying with insecticides does not work because the chemical is absorbed by the plant material and degraded. In addition, adult stable flies can fly in from surrounding areas, and can result in widespread infestation in the neighborhood.
Stable fly breeding usually does not occur within the lot, but under fence lines or feed bunks, where material collects undisturbed. A small amount of old damp manure or decomposing wet feed can produce hundreds of stable flies.
A field test to determine efficacy of pyrethroid pour-on products against stable flies was conducted on dairy cattle in the central valley of California. Products used were: Boss (5% permethrin, Schering-Plough Animal Health), Brute (10% permethrin, Y-Tex Corporation), CyLence (1% cyfluthrin, Bayer Inc.), and Durasect (1% permethrin, Pfizer Animal Health).
Applications were made at label rates based on animal weight. Animals were treated early July, and stable fly numbers were checked for three weeks. Approximately 3400 animals were treated on five dairies. Fly counts were made on 15 animals per pen on each dairy. Animals were sampled randomly and no effort was made to count the same animals on follow-up dates.
All products reduced fly numbers for one day on some of the dairies, but none had any effect by the third day following treatment. Even when on-animal stable fly numbers decreased, the reduction was not dramatic. Thus it does not appear that pour-on pyrethroid products are effective against stable flies on dairy cattle.
Stable flies preferentially feed on the lower portions of cattle (around the legs and belly, including the udder). They feed quickly and fly away, minimizing exposure to any insecticides applied to these areas. Additionally, insecticides applied to these body regions are rubbed off by contact with vegetation and mud, or washed off when animals are rinsed prior to milking.
Because chemical control options are so limited, source reduction, or larval breeding site elimination, are particularly critical in stable fly suppression. Stable fly larvae develop in damp plant material such as soggy hay, old wet manure, and poorly composting lawn clippings. These materials should be spread in a thin layer to dry in the sun, or dealt with in some manner that will render them unsuitable for fly breeding. Spraying with insecticides does not work because the chemical is absorbed by the plant material and degraded. In addition, adult stable flies can fly in from surrounding areas, and can result in widespread infestation in the neighborhood.
Stable fly breeding usually does not occur within the lot, but under fence lines or feed bunks, where material collects undisturbed. A small amount of old damp manure or decomposing wet feed can produce hundreds of stable flies.
A field test to determine efficacy of pyrethroid pour-on products against stable flies was conducted on dairy cattle in the central valley of California. Products used were: Boss (5% permethrin, Schering-Plough Animal Health), Brute (10% permethrin, Y-Tex Corporation), CyLence (1% cyfluthrin, Bayer Inc.), and Durasect (1% permethrin, Pfizer Animal Health).
Applications were made at label rates based on animal weight. Animals were treated early July, and stable fly numbers were checked for three weeks. Approximately 3400 animals were treated on five dairies. Fly counts were made on 15 animals per pen on each dairy. Animals were sampled randomly and no effort was made to count the same animals on follow-up dates.
All products reduced fly numbers for one day on some of the dairies, but none had any effect by the third day following treatment. Even when on-animal stable fly numbers decreased, the reduction was not dramatic. Thus it does not appear that pour-on pyrethroid products are effective against stable flies on dairy cattle.