Haematobia irritans

Geographic Range

Haematobia irritans is found on the continents of North and South America, Asia, Africa and Europe. In North America, H. irritans lives year round in the Sourthern United States, while in the summer months it ranges north into Cananda. (Roberts and Janovy, 2000)


In North America, pastures containing herds of large mammals are the typical habitat of H. irritans. (Blume, et al., 1970; Skidmore, 1985)

Physical Description

Adults are quite small, approximately half the size of a house fly. Haematobia irritans is gray in color with the large compound eyes and reduced antennae typical of flies in the infraorder Muscomorpha. Larvae of H. irritans are approximately 7mm long. The maggots are a pale yellow color, with a simple, elongate, body that lacks a sclerotized head. A pair of sclerotized, vertically biting mandibles are visible on the anterior end of the head. (Roberts and Janovy, 2000; Skidmore, 1985)

  • Average length
    7 mm
    0.28 in


Gravid females lay approximately 18 eggs in groups of 4-6 on fresh cattle droppings. Larvae hatch within 24 hours and begin feeding. After five days, the larvae have passed through three instar stages and are ready to pupate. Adults emerge from the puparium five days later. In colder climates, however, the life cycle of H. irritans may take up to three weeks for completion. (Skidmore, 1985)

  • Average eggs per season


Haematobia irritans, while able to fly, almost never leaves its host, instead staying on the same cow to feed 24 hours a day. The only time H. irritans takes flight is immediately after the cow defecates. Haematobia irritans uses this opportunity to lay eggs while the dung is still at body temperature. Adult flies will leave the host to lay eggs at any time of day so long as fresh manure is present. (Blume, et al., 1970; Skidmore, 1985)

Food Habits

Haematobia irritans, while able to fly almost never leaves its host, instead staying on the same cow to feed 24 hours a day. Adult Haematobia irritans is an ectoparasite, found all over the skin of cattle. It is a telmophage, using its labella to pierce the skin of a cow, so that the fly may suck up the blood that flows into the wound. Larvae feed on the feces of large ungulates. (Roberts and Janovy, 2000)

  • Animal Foods
  • blood
  • Other Foods
  • dung


The predatory larvae of several other species of insect, including beetles of the family Staphylinidae, prey upon the larvae of H. irritans. In order for H. irritans larvae to have a chance to develop, their eggs must be laid quickly; before those of other insects. (Blume, et al., 1970; Roberts and Janovy, 2000; Skidmore, 1985)

Economic Importance for Humans: Positive

There are no known economic benefits derived from this species.

Economic Importance for Humans: Negative

A serious pest of cattle, H. irritans can cause cows to lose weight and lower milk production by biting while the cows attempt to feed. Cattle spend time trying to relive themselves of irritation rather than eating. Thousands of H. irritans can be present on a single cow, causing that cow extreme discomfort. In addition to simply bothering cattle, H. irritans is capable of transmiting the nematode Stephanofilaria stilesi. This nematode causes damage to the skin of cows. Attempts have been made to eradicate H. irritans using pesticides. Unfortunatley, resistant populations of H. irritans emerge within a few weeks after treatment begins. (Derouen, et al., 1995; Roberts and Janovy, 2000)

Conservation Status

Haematobia irritans requires no special conservations status.

Other Comments

This species is thought to have been introduced to North America from Europe in cattle shipments. (Blume, et al., 1970; Skidmore, 1985)


Sara Diamond (editor), Animal Diversity Web.

Michael Harris (author), University of Michigan-Ann Arbor, Teresa Friedrich (editor), University of Michigan-Ann Arbor.



Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

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living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

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living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

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living in the southern part of the New World. In other words, Central and South America.

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living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

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living in landscapes dominated by human agriculture.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


an animal that mainly eats meat

causes or carries domestic animal disease

either directly causes, or indirectly transmits, a disease to a domestic animal


an animal that mainly eats the dung of other animals


animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature


union of egg and spermatozoan


having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

internal fertilization

fertilization takes place within the female's body


having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.


reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.


an animal that mainly eats blood


offspring are all produced in a single group (litter, clutch, etc.), after which the parent usually dies. Semelparous organisms often only live through a single season/year (or other periodic change in conditions) but may live for many seasons. In both cases reproduction occurs as a single investment of energy in offspring, with no future chance for investment in reproduction.


reproduction that includes combining the genetic contribution of two individuals, a male and a female


that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).


the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.


A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.


Blume, R., S. Kunz, B. Hogan, J. Matter. 1970. Biological and Ecological Investigations of Horn Flies in Central Texas: Influence of Other Insects in Cattle Manure. Journal of Economic Entomology, 63: 1121-1123.

Derouen, S., L. Foil, J. Knox, J. Turpin. 1995. Horn Fly (Diptera: Muscidae) Control and Weight Gains of Yearling Beef Cattle. Veterinary Entomology, 83: 666-668.

Hu, G., J. Frank. 1996. Effect of the Arthropod Community on Survivorship of Immature Haematobia Irritans (Diptera: Muscidae) in North Central Florida. Florida Entomologist, 79: 497-502.

Roberts, L., J. Janovy. 2000. Foundations of Parasitology. Boston: McGraw Hill.

Skidmore, P. 1985. The Biology of the Muscidae of the World. Dordrecht: Dr W. Junk Publishers.