Haematobia irritans, the horn fly, is a small fly (about half the size of a common housefly) of the genus Haematobia which is the European genus of bloodsucking flies. Haematobia irritans is a native of Europe but has been introduced to North America and is considered a potentially dangerous livestock pest.
The larvae remain in fresh pats of the animal's dung and feed on the both the resident bacterium and the compositions of the decomposition products of the resident bacterium.
The adult, on finding a suitable host, remain on it and others in the same herd for life, with the female only leaving to lay her eggs. Horn flies will also move around to different areas on the same animal to regulate their temperature and minimize their exposure to the wind. Both the male and the female subsist completely on blood, using their sharp mouthparts to pierce the animal's hide to suck it out.
Males typically feed around 20 times and females around 40 times daily, and when not feeding they tend to rest around the horn region of the host.
The first stage is the egg, which is laid in fresh feces, and hatches quickly. The resulting larval (maggot) stage, which consists of three larval instars (wingless), develops quickly and can last as little as four days. This is followed by the still immature pupa stage (also wingless) which lasts around six to eight days and finally the mature, winged adult stage.
Generational time may be as little as ten days under ideal conditions, but under less favorable circumstances can average between 14 to 18 days.
Due to the level of damage an infestation can result in, much has been done over the years in the effort to manage, reduce, and eliminate the horn fly. Traditional methods were through the use of pour-ons, backrubbers and face powder bags, with products such as Co-Ral which is available as dust for face/horn flies. Self-applicator methods such as dust bags and backrubbers are used mainly for range or pasture herds, and are placed so that the animal cannot avoid coming into contact with it, such as at a gate through which animals pass. More recently, control of the horn fly by using ear tags on cattle has been extremely successful. The ear tags are comprised of a PVC matrix impregnated with pyrethroid, and can be effective for between 16 to 24 weeks. Originally, the ear tags were developed and used against such pests as ticks and by 1983 50% of cattle had ear tags. Long periods of such dosing resulted in the elimination of 95-99% of susceptible flies, but this strong selection pressure ended up resulting in the development of resistant strains of the flies. To combat this, the use of organophosphates and piperonyl butoxide as a synergist are now recommended to be alternated with pyrethroid to help slow resistance. In addition, methoprene in the form of sustained release bolus (a rounded mass of food or pharmaceutical preparation ready to swallow) inhibits the emergence of an adult insect from a pupal case or an insect larvaa from an egg for up to 7 months.
CASE STUDY: Impact of Horn Flies, Haematobia irritans (L.) (Diptera: Muscidae), on the Behavior of Beef Steers
Dec 01, 2008; ABSTRACT The horn fly (Haematobia irritans L.) is a common pest of cattle that can reduce animal performance. Beef steers grazing...
New Pestivirus Study Findings Recently Were Published by Researchers at Auburn University, Department of Clinical Sciences.(Clinical report)
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