Horn Fly Control Research Articles

Control of Face Flies and Horn Flies with Experimental Diflubenzuron Boluses, 1988

Abstract Two bolus formulations of 4.75 g (9.7% AI) flaked and powdered diflubenzuron were administered to beef cattle to test their efficacy against horn flies and face flies. Commercially available Vigilante° and methoprene boluses were used as standard treatments. Experimental diflubenzuron and Vigilante boluses were administered to cattle at the rate of 1 bolus/250 kg body weight. Methoprene boluses were administered at a rate of 1 bolus/300 kg body weight. Herd size ranged from 20-48 adult cattle/herd, and all herds were geographically located within 30 miles of each other. Two similar untreated herds were observed to compare treatment effectiveness. All treatments were administered between 20 May and 24 May. Horn fly numbers were estimated on one side of each animal, and face flies were counted on the head and face of the same animals.

Horn and Face Fly Control on Pastured Beef Cattle with Insecticidal Ear Tag Preparations, 1989

Abstract Experimental and commercially available ear tags were evaluated under field conditions for their efficacy against horn and face flies on pastured beef cattle in central Kentucky. The horn fly populations on all herds tagged were sampled and tested for permethrin resistance using the Kentucky horn fly resistance test procedure prior to tagging. A susceptible horn fly population obtained from USDA Livestock laboratory, Kerrville, TX was used as a comparison for all resistance tests. The tags were placed on all adult animals at the rate of one tag/ear. The commercial tags used were Maxcon™, Optimizer™, Terminator™, Saber ™, Tomahawk ™, and Ranger ™. The experimental tags included Mobay’s 15% fenthion + 10% coumaphos, 20% fenthion, 20% fenthion + 15% piperonyl butoxide, and 10% cyfluthrinate and Y-TEX corporation’s YT609A (20% diazinon) and YT305 (cypermethrin). All herds were tagged between 5-15 Jun with the exception of one herd tagged with a 20% fenthion ear tag on 30 Jun. Face flies were counted on the head and face of 10 randomly selected animals/farm while horn flies were estimated on one side of the same animals. Fly counts were compared to those on untreated herds further than 0.5 km, but less than 5 km from the treated herds.

Vigilante®, Terminator®, and Warbex® for Horn Fly Control on Beef Cattle, 1987

Abstract The Vigilante bolus (5% diflubenzuron), the Terminator ear tag (20% diazinon), and Warbex (pour-on, 13.2% famphur) were administered in horn fly efficacy trials at the Simpson Agricultural Experiment Station in upstate South Carolina. Vigilante boluses were administered to cattle based on the weight of the animal with a standard balling gun (136 to 250 kg received Yz bolus; otherwise Vt bolus per 102 kg body weight). No animal received more than 2 boluses. The Terminator ear tags were applied 2 per head. Mixed breed beef cows were divided randomly into five herds for application of treatments in this study. Forty-two cows with calves were orally administered Vigilante boluses on 18 Jun. All animals of this herd were also treated with Warbex at the label rate. A second herd of 30 cows with calves was treated with boluses only on 19 Jun. A third her-d of 39 cows with calves was bolused, and adult cows also were tagged with Terminator tags. A fourth herd of 58 cows with calves was left as an untreated control. On 7 Jul, 2 weeks after the boluses were administered, a fifth herd of 41 cows without calves were tagged with 2 Terminator tags/animal. The number of flies on one side of 10 randomly selected cows/herd was counted each wk for 11-wk posttreatment with the aid of binoculars between the hours of 0900 and 1200 EST.

Efficacy of Optimizer Ear Tags on Pyrethroid Resistant Horn Flies, Gudmundsen Sandhills Laboratory, Whitman, Nebraska, 1989

Abstract One-hundred and fifty crossbred cow/calf pairs were randomly selected for the study. Two groups of 50 cow/calf pairs were provided Optimizer (20% Diazinon) ear tags for horn fly control. Tags were applied at one tag/cow. A third group of 50 cow/calf pairs served as an untreated control. Calves were weighed and cows were ear tagged 30 May and placed in their respective pastures. Horn fly counts were recorded weekly by counting both sides of a cow with a minimum of 15 cows counted during each observation.

Efficacy of Yt-607-C3 Ear Tags for Controlling Horn Flies and Face Flies, West Central Research and Ex-Tension Center, North Platte, Nebraska, 1988

Abstract Y-Tex experimental YT-607-C3 ear tags were applied to 200 yearling heifers (one tag/head) 17 Jun. An untreated control group of 16 heifers was used as comparison. Fly counts were recorded on a weekly basis. Horn fly counts were made by counting the number of flies on both sides of an animal. Face fly counts were made by counting the total number of flies per face. A minimum of 15 heifers/group were counted at each counting date.

Walk-through trap for control of horn flies (Diptera: Muscidae) on pastured cattle.

A walk-through fly trap designed in 1938 by W. G. Bruce was tested for two field seasons in Missouri. Screened elements along both sides of the device functioned as cone traps, thereby catching horn flies, Haematobia irritans (L.), as they were swept from cattle by strips of carpet hung from the roof. Horn fly control on pastured cattle averaged 54 and 73% when they were afforded access to the trap. Analyses of Diptera captured in the trap indicated that horn flies comprised the most abundant species; face flies, Musca autumnalis De Geer, stable flies, Stomoxys calcitrans (L.), and others were present in smaller numbers. Cattle were not reluctant to use the trap, and no structural problems were observed during the experiment.

Control of Face Flies and Horn Flies on Pastured Dairy Heifers with Insecticidal Ear Tags, 1988

Abstract Ear tag efficacy trials were conducted on pastured herds (15-50 head/herd) of dairy heifers in Howard and Carroll counties, Md. Four herds were not tagged and served as controls. During the first 3 wk of May, cattle in Herds 1, 2, 4, and 5 were tagged with 2 Atroban or Terminator tags. Cattle in Herd 3 were tagged with 2 Atroban tags the third week in June. These herds were monitored for face flies and horn flies from June through September. Fly density was determined by making weekly counts of the number of face flies/face and horn flies/side on 15 animals in each herd.

Control of Face Flies and Horn Flies with Experimental Diflubenzuron Boluses, 1988

Abstract Two bolus formulations of 4.75 g (9.7% AI) flaked and powdered diflubenzuron were administered to beef cattle to test the formulations’ efficacy against horn flies and face flies. Commercially available Vigilante and methoprene boluses were used as standard treatments. Experimental diflubenzuron and Vigilante boluses were administered to cattle at the rate of 1 bolus/250 kg body weight. Methoprene boluses were administered at a rate of 1 bolus/300 kg body weight. Herd size ranged from 20 to 48 adults/herd, and all herds were located within 30 miles of one another. Two similar untreated herds were observed for comparison of treatment effectiveness. All treatments were administered between 20 and 24 May 1988. Horn fly numbers were estimated on one side of each animal, and face flies were counted on the head and face of the same animals.

Organophosphorus insecticides for the control of pyrethroid-resistant horn flies (Diptera: Muscidae).

Toxicitiesof selected organophosphorus insecticides were determined for pyrethroid-resistant and susceptible horn flies, Haematobia irritans (L.), in the laboratory. Although possessing approximately 20-fold resistance to the pyrethroids permethrin and fenvalerate, the pyrethroid-resistant strain displayed virtually no cross-resistance to the nine organophosphorus insecticides tested (resistance ratios ranged from 0.8- to 2.7-fold). Field tests of several of the organophosphorus insecticides (stirofos, chlorpyrifos, dioxathion, and diazinon) indicated that diazinon provided good control of pyrethroid-resistant horn flies for up to 16 wk. In another field test, diazinon and pirimiphos-methyl alone (two tags per head) provided good horn fly control during the 8 wk study. When applied in combination (one tag of each per head), the level of horn fly control achieved was very similar to that observed for each insecticide alone.

A reservoir neckband system for delivery of organophosphorus insecticides to cattle

Abstract Because of the problem of pyrethroid resistance in the horn fly, alternatives to the controlled-release insecticidal ear tags are being explored. In laboratory studies, the rate of 5 selected organophosphorus insecticides from polymeric reservoirs of 10 different compositions was determined. Based on the results of the laboratory studies, chlorfenvinphos, diazinon, and crotoxyphos were loaded into thin-walled poly(vinyl chloride) reservoirs and fabricated into neckbands for cattle. In field trials, reservoir neckbands containing chlorfenvinphos, diazinon and crotoxyphos provided 91%, 88% and 53% control of horn flies, respectively.

Control of horn flies on cattle with insecticide pellets fired from a CO 2-operated pistol

A method is needed to control pyrethroid-resistant horn flies ( Haematobia irratans) which would involve the intermittent application of insecticides to cattle without their confinement for treatment. Our objective was to test a CO 2 gas-operated pistol, designed to shoot marking pellets, to determine the number of pellet applications required to obtain season-long control. Also, since horn fly resistance to pyrethroid insecticides is widespread, we tested ten other insecticides as concentrates in pellets. Six pellet pistol applications of 38% permethrin provided 84% control of horn flies for 15 weeks. Single pellet applications of ten non-pyrethroid insecticides indicated that none of these insecticides, at the concentrations tested, were as effective as permethrin for control pf pyrethroid-resistant horn flies. Our field evaluation of the pellet-pistol method indicates that it has sufficient merits to justify further testing for horn fly control.

Horn fly and face fly control with the Dustacator® combination mineral feeder and livestock dusting device (1988)

Dustacators (combination mineral feeders and livestock dusting devices) were used for four beef herds at Kansas State University in 1985. Loose mineral was supplied in all four Dustacator tubs, which were adjusted to low settings. Permethrin dust had no apparent effect on horn flies. Co-Ral® from two sources and Rabon® provided approximately 65% horn fly reduction during the 53-day test period. The 1986 experiment compared the effects of Dustacator mineral tub height adjustments and loose vs. block mineral. Co-Hal 1% dust from a single source was used in all treatments on two Simmental herds and two Polled Hereford herds. Excellent horn fly control was achieved and maintained except for a temporary increase in horn fly numbers in early September in all treatments. Face fly control was inadequate in all treatments in both years. Use of block mineral was related to reduced mineral consumption and self-application of more insecticide dust. High tub adjustment was related to greater mineral consumption but reduced self-application of insecticide. The degree of fly control was not correlated with amount of insecticide used either on a per-cow or per-herd basis. Simmentals consumed nearly twice as much mineral per head as Polled Herefords, but they used only 20% more insecticide. Including the cost of 1% Co- Ral dust and equipment costs amortized over 5 years, Dustacators provided acceptable horn fly control and some reduction of face fly numbers for $1.62 per cowlcalf pair, plus labor.

Horn and Face Fly Control on Pastured Reef Cattle with Insecticidal Eartag Preparations, 1987

Abstract Various cattle eartags designed for horn and face fly control were evaluated under field conditions for their efficacy. All herds tested were cow/calf operations located in central and western Kentucky where resistance is becoming more prominent in cattle operations. Prior to treatment the resistant ratio (RS) to permethrin was determined with the KY horn fly resistant test procedures. A permethrin susceptible horn fly strain was used for comparison. All herds were tagged between 15—30 Jun and the herds monitored for horn and face flies at 2 wk intervals. Face flies were counted on the head and face of 10 animals while horn Ilies were counted on one side of the same animals. Commercially available Maxcon (tm), Atroban (tm), and Terminator (tm) flytags were tested along with preparations containing 10% and 15% cyhalothrin (Cy) with piperonyl butoxide and S,S,S-Tributylphosphorotrithioate (Def). Tags containing 22% cyhalothrin with and without calcium carbonate (CaC03) were tested as were tags containing 22 and 35% pirimophos methyl (PM). Tags were applied to all animals in the herds except for spring calves (1987).

Control of Face Flies and Horn Flies on Pastured Dairy Heifers with Pyrethroid Ear Tags Or Tapes, 1986

Abstract Ear tag efficacy trials were conducted on pastured herds (15-40 head/herd) of dairy heifers in Howard and Carroll counties, Maryland. Two herds received no treatment and served as checks. Six other herds (2/treatment) were tagged as follows: Guardian® ear tags, 2/head, attached 3 and 8 May; Duo Deckem® ear tags, 2/head, attached 30 May and 6 Jun; and Atroban® ear tags, 2/head, attached 1 Apr and 7 Jun. A ninth herd had an Ectiban® ear tape attached to one identification ear tag on each of ca. 40 heifers on 10 May. Treatment efficacy was determined by counting weekly the number of face flies/face and horn flies/ side of 15 animals.

Control of Face Flies and Horn Flies on Pastured Dairy Heifers with Insecticidal Ear Tags Or Tapes, 1987

Abstract Ear tag efficacy trials were conducted on pastured herds (15-50 head/herd) of dairy heifers in Howard and Carroll counties, Maryland. Two herds were not tagged and served as checks. During the period of time from 20 Apr-20 May, 2, 3, and 4 herds were tagged (2/head) with the following commercially available tags: Ectrin, Guardian, and Terminator. These herds, as well as 1 additional herd in which the heifers were treated with 1 Ectiban tape attached to an identification tag, were monitored for face flies and horn flies during the months of May-Sep. Fly density was determined by making weekly counts of the number of face flies/face and horn flies/side on 15 animals in each herd.

Effect of cattle breed and flucythrinate-impregnated ear tags on horn fly (Diptera: Muscidae) control on yearling heifers.

Horn fly, Haematobia irritans (L.), counts were reduced 96–97% when Angus × Hereford (A × H) and Brahman × Hereford (B × H) yearling heifers were tagged with flucythrinate-impregnated ear tags. Horn fly populations on B × H heifers were 67–75% less than on A × H heifers. Correlations and regressions of average fly count on weight gain, hip height, tail bone length, brush length, and back-fat thickness were low. Bovine keratocon-junctivitis did not occur among B × H heifers and was reduced by tagging A × H heifers. Weight gains of A × H heifers were 6% greater when they were tagged, but tagging did not increase weight gains of B × H heifers.

Control of stable flies and horn flies (Diptera: Muscidae) with permethrin tapes applied to tails of beef and dairy cattle.

Ear and tail tapes containing ampules of viscous preparations of permethrin were applied to tails of beef and dairy cattle. Horn flies, Haematobia irritans (L.), were controlled for 9 wk on beef cattle and 4 wk on dairy cattle. When applied via the tail, the same permethrin preparation was more efficacious than when applied via the ear. Retention problems were experienced with both cattle types but were aggravated by wet conditions at the dairy. Although no stable flies, Stomoxys calcitrans (L.), were present on the beef animals, at least two discrete concentrations of adult stable flies were identified on the dairy. The effects of stable fly behavior on control are discussed. Further development of the tail tape is advocated, as is its use in integrated pest management programs for fly control on cattle.

Effects of horn fly (Diptera: Muscidae) control on cows and gastrointestinal worm (Nematode: Trichostrongylidae) treatment for calves on cow and calf weight gains.

Horn flies, Haematobia irritans (L.), at an average population level of 197 per cow, did not significantly affect cow, calf, or cow/calf seasonal weight gains during a 3-yr study in the central sandhills of Nebraska. Cattle aggregation was not influenced by horn fly population levels encountered in this study. Treatment of calves with a anhelmintic drug (thiabendazole) increased calf weight gains significantly despite a helminthic infection without clinical symptoms.

New approaches to the chemical control of arthropod pests of livestock

Chemicals are important tools in our effort to control livestock ectoparasites, and they are likely to remain so in the foreseeable future. Chemical control is the most widely used and in most cases the only method available to the producer. Therefore, it is imperative that we continue to seek new chemicals as well as new systems for delivery of those chemicals in an effective, efficient, and safe manner. New approaches to chemical control involve both new chemicals and new delivery systems in a complementary and often a synergistic relationship. Three relatively new classes of chemicals, pyrethroids, insect growth regulators, and avermectins, have provided special opportunities for development of new delivery systems. The development of the insecticidal ear tag has been perhaps the most significant new approach to chemical control of livestock ectoparasites in recent years. Although originally developed for control of ear ticks, the tag has had its greatest impact on control of the horn fly, a major pest of cattle in the U.S. The pyrethroid tags provided season-long control of horn flies in most climates and at the same time dramatically reduced the use of pesticide. Unfortunately, the problem of resistance to pyrethroids in the tags has been encountered. Unless effective techniques for resistance management can be developed, the producer may lose this valuable new tool. Sustained-release boluses provide a means of delivering IGR's, such as methoprene and diflubenzuron, for control of immature stages of the horn fly and face fly in manure of cattle. These devices are designed to lodge in the reticulum of cattle and release the chemical to the digestive tract over an extended period. Bolus formulations may in fact provide a tool for management of horn fly resistance to pyrethroids. Ivermectin, a potent new chemical from a new class of agricultural pesticides, provides an important opportunity for developing innovative delivery systems for control of livestock pests. Its systemic activity against ticks and blood-sucking flies at extremely low dosages provides potential for development of long-lasting subcutaneous implants. Its ability to control immature stages of dung-breeding flies, such as the horn fly and face fly, offers the potential for development of sustained-release boluses for larvicidal treatments. These three selected examples of new approaches to chemical control of livestock ectoparasites point to two obvious trends: 1) reduction in quantity of a chemical to be applied without sacrifice of efficacy and 2) use of controlled-release technology to prolong effectiveness of the chemical. Although the examples presented are focused on applications to cattle, similar approaches have application for other livestock. New approaches such as these have important implications in implementation of either area-wide or IPM control programs. Such programs will need convenient and effective chemical delivery systems to be successful if in fact chemicals are to be a part of the programs.

Insecticide Mixtures as an Approach to the Management of Pyrethroid-resistant Horn Flies (Diptera: Muscidae)

The pyrethroids permethrin and cypermethrin were mixed in selected ratios with a synergist (piperonyl butoxide [PB]) and an organophosphorus insecticide (chlorpyrifos) to determine their efficacy on susceptible and resistant populations of horn flies, Haematobia irritans (L.), in the laboratory and field. The addition of either PB or chlorpyrifos to the pyrethroids increased toxicity 1.4- to 4.2-fold and did not change resistance ratios compared with the pyrethroids alone. The pyrethroid/chlorpyrifos/synergist mixture changed toxicity 8.6- to 0.4-fold and generally reduced the level of resistance, compared with the pyrethroids. Field evaluations revealed that no mixture maintained resistant horn fly populations below economically damaging levels, but the addition of PB or chlorpyrifos or both generally improved control. Based on available information concerning toxicity, resistance, and long-term considerations, pyrethroids should be excluded from use in ear tag mixtures for horn fly control.