Numbers
S. calcitrans is the only species in Genus Stomoxys listed at
Nearctica.com.Size
Adults average 8 mm in length. Larvae range in size from 5 to 12 mm long. The pupae are 4 to 7 mm long.
Identification
The stable fly closely resembles the common housefly (Musca domestica). Unlike the common housefly, Stomoxys calcitrans have a broader abdomen. Adult stable flies have a gray body, and can be identified by four characteristic longitudinal stripes across the thorax as well as several dark spots on top of the abdomen. On the vertex and frons there are three ocelli and two large compound eyes. Sexual dimorphism occurs in this species, and there is more distance between the compound eyes in females. The proboscis of the stable fly is black, long, and thin, protruding from the front of the head. Its other mouthparts are modified, with the labellum having rows of teeth in order to pierce the skin of its host. The palps are one third of the length of the proboscis.
Mature larvae are yellowish white maggots, and are a cylindrical shape that tapers anteriorly.. The pupae have a reddish-to-dark brown exterior. The posterior spiracles on the puparia are black with three S-shaped yellow slits, and are lightly sclerotized. (Bishop, 1913)
Range
Stomoxys calcitrans is a cosmopolitan insect, meaning that it can be found worldwide as long as suitable food and weather conditions can be met.
Habitat
The habitat of the stable fly, as suggested by its common name, is almost anywhere that horses, cattle, and other agricultural animals can be found (especially inside barns and stables). (Bishop, 1913; Janovy and Roberts, 2000)
Food
Stomoxys calcitrans is a daytime feeder. The adults of both sexes feed on blood. There is low host specificity; although they feed mainly on the blood of cattle and horses. Adults locate a host by sight, and feeding is usually completed in two to five minutes. After feeding the stable fly is sluggish, and remains motionless near the host. The stable fly will generally feed from many hosts before it is replete. Studies show that there is a rise in feeding during warm weather, whereas there is a decrease in feeding rates during rain. After hatching, the larvae begin feeding on local microbial flora and fauna. (Bishop, 1913; Janovy and Roberts, 2000)
Life Cycle
Stomoxys calcitrans eggs take one to four days to develop. The length of this period is affected by temperature, humidity, and how long the egg was retained by the female. The larval stage lasts from 11 to 30 (and sometimes more) days, based upon habitat suitability and availability of food. After the third instar (growth stage) the maggot will pupate for 6 to 20 days. As with larval maturation, length of pupation is based upon food abundance and quality during larval growth. (Bishop, 1913)
