Musca domestica

Linnaeus, 1758

house fly, common house fly

is a fly and the most abundant insect in confined cattle operations. are small (6–7 mm), gray with four dark longitudinal stripes on the and creamy yellow abdominal sides. They do not bite but feed on blood, sweat, tears, saliva, and other bodily fluids, causing cattle to exhibit defensive including ear flapping, shaking, and feeding hesitancy. The completes development from to adult in as little as two weeks under optimal conditions, with up to 12 annually in temperate climates. Females deposit 75–150 eggs per batch in decaying organic matter, particularly manure and rotting vegetation. House flies are mechanical of over 200 including E. coli, and can infest cattle wounds with maggots.

Musca domestica by no rights reserved, uploaded by Richard Fuller. Used under a CC0 license.

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HK house fly 蒼蠅 Musca domestica August 2024 R12S 05 by Spidamin 888 Simnonz. Used under a CC0 license.

Pronunciation

How to pronounce Musca domestica: /ˈmʌskə dəˈmɛstɪkə/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from similar flies by smaller size (6–7 mm vs. larger blow flies and flesh flies), four dark thoracic stripes, and creamy yellow abdominal sides. Smaller than blow flies (Calliphoridae), which are often metallic and robust. Flesh flies (Sarcophagidae) have bold black thoracic stripes and scarlet with red-tipped in males. Stable flies (Stomoxys calcitrans) are similar in size but possess piercing mouthparts for blood-feeding. House flies have sponging mouthparts and do not bite.

Images

Appearance

measure 6–7 mm in body length. Overall dull gray coloration with four dark longitudinal stripes on the . Sides of are creamy yellow and distinctly noticeable. is white with large, dark reddish . Eyes converge and nearly meet at top of in males; more widely separated in females. Single pair of membranous wings. Body slightly hairy.

Habitat

Confined livestock facilities including feedlots, dairies, barns, and poultry operations. Breeds continuously in manure, rotting vegetation, and decaying organic matter. Associated with human dwellings and animal husbandry enterprises worldwide. One pound of moist manure or wasted feed can support production of up to 1,000 larvae; larvae cannot survive on manure with less than 30% moisture.

Distribution

found worldwide in association with human and animal . Believed to have originated in steppe regions of interior central Asia, spread globally via livestock traffic and commerce. Present throughout North America including Texas, where it is the most abundant fly in confined cattle operations.

Seasonality

Most abundant during warmer months; continuous breeding in suitable conditions. Ten to twelve annually in temperate climates. Unlikely to be encountered in winter in northern latitudes, though may persist indoors or in southern regions.

Diet

feed on blood, sweat, tears, saliva, and other bodily fluids using sponging mouthparts; do not bite. Larvae develop in manure and decaying organic matter. In feeding studies, adults consumed sugar solutions at 8–9 mg per fly per 2 hours versus dry sucrose at approximately 2 mg per fly per 2 hours due to mouthpart requiring liquid food.

Life Cycle

Complete . to in as little as two weeks under optimal conditions. Females deposit batches of 75–150 eggs in three to four day periods directly into food source. Larva twice; third molt produces pupal stage enclosed in capsule-like formed from last larval skin. occurs in drier locations adjacent to breeding medium. Adults emerge using to break out of puparium.

Behavior

Exhibits to maintain cleanliness and evade threats. Defensive behaviors in cattle include ear flapping, shaking, tail switching, and feeding hesitancy when flies swarm around heads seeking protein from secretions. Females avoid oviposition on colonized by fungi due to volatile chemical cues signaling unsuitable developmental conditions. Behavioral documented: contact irritancy (leaving treated area after physical contact), spatial repellency (leaving without contact), and reduced feeding on contaminated baits.

Ecological Role

Mechanical of numerous to humans and animals including E. coli and -causing organisms causing illnesses from diarrhea to typhoid fever. Nutrient recycler in manure decomposition. for obligate fungal Entomophthora muscae, which manipulates host sexual to enhance spore . Competitor with other filth flies for breeding resources; larvae preyed upon by fire ants, black dump fly larvae, and parasitic .

Human Relevance

Major pest of livestock operations causing economic losses through transmission, wound , and feeding disruption in cattle. Control costs approximately $1 billion annually for poultry, pig, and dairy farmers. Emerging value in agricultural waste recycling: larvae convert manure to protein-rich (55–63% protein, 15–23% fat) for animal feed and biodiesel production, with usable as soil amendment. Subject to intensive resistance management due to documented physiological and behavioral resistance to multiple chemical classes.

Similar Taxa

Stomoxys calcitransSimilar size and appearance but possesses piercing mouthparts for blood-feeding; inflicts painful bite and rests on nearby surfaces after feeding rather than remaining on animal.
Haematobia irritansHorn fly is smaller (3/16 in.), same general coloration, but bites cattle and feeds on blood 30–40 times daily; remains on animal rather than swarming around .
CalliphoridaeBlow flies are larger, more robust, often metallic, and overwinter as ; can be seen on sunny winter days basking on buildings.
SarcophagidaeFlesh flies have bold black thoracic stripes, scarlet , and red-tipped in males; more abundant in urban areas than house flies.

Misconceptions

Often mistaken for other flies during winter when true house flies are absent; blow flies and flesh flies are frequently misidentified as house flies. The water-filled bag deterrent technique lacks scientific validation despite popular claims.