Date of this Version
Journal of Vector Ecology, Vol. 36, no. 2, December 2011
The Stomoxyini is a small tribe with only ten genera and 49 known species worldwide (Zumpt 1973) belonging to the Muscidae, one of the largest dipteran. Apart from feeding occasionally on nectar (Müller et al. 2011a), the adult flies of this tribe are obligate blood feeders and can easily be recognized by their conspicuous proboscis adapted for biting and sucking blood (Zumpt 1973). Several members of the tribe, especially Stomoxys and Haematobia species, are major pests of domestic livestock. Two species, Stomoxys calcitrans (Linnaeus 1758) and Haematobia irritans (Linnaeus 1758), cause billions of USD in damages annually in the cattle industry (Byford et al. 1992, Hogsette et al. 1991, Taylor and Berkebile 2006). Haematobia irritans is known to be a vector of nematodes like Stephanofilaria stilesi Chitwood (Hibler 1966), and several Staphylococcus spp. bacteria that cause mastitis or infection of the teats (Owens et al. 1998). Stomoxys calcitrans is a vector of the nematode, Habronema microstoma (Zumpt 1973), and has been shown to transmit many pathogens, mostly under laboratory conditions (Greenberg 1971, Mihok et al. 1995, Sumba et al. 1998). Nevertheless, it is the painful, often multiple bites of the Stomoxyini which cause decreased weight gain and reduction in milk production in livestock because of defensive behavior (Foil and Hogsette 1994). Though Stomoxyini are zoophilic, some species will also bite humans, especially in the absence of livestock (Zumpt 1973).
In two recent outbreaks of lumpy skin disease during 1989 and 2006 in several dairy farms in Israel, S. calcitrans was suspected as a possible vector (Yeruham et al. 1995, Brenner et al. 2006). At that time, little was known about the distribution and phenology of this species in Israel. This initiated a two-year survey in 2006 to collect biting flies (mainly Stomoxyini and Tabanidae), active diurnally, from 38 Israeli and 11 Palestinian farms. The flies were collected at each selected site for one or two years, with six Alsynite traps (Hogsette and Ruff 1990) per site. During the same time, flies at seven Israeli and four Palestinian farms were collected monthly with Malaise traps and sweep nets. Additionally, from 2006 to 2010 we collected biting flies with sweep nets from grazing animals, including cattle, horse, donkey, camel, sheep and goat, throughout Israel. Malaise and Nzi traps were operated regularly during the five-year period in natural habitats in the major phyto-geographical zones of Israel. Stomoxyini flies were also collected from flowers and fruits in natural habitats and from plant-baited traps. During the survey, six species, Stomoxys calcitrans, Stomoxys sitens Rondani 1873, H. irritans, Haematobia minuta (Bezzi, 1892), Stygeromyia maculosa Austen, 1907, and Haematobosca stimulans (Meigen, 1824), were collected.
The stable fly, S. calcitrans, is cosmopolitan in distribution. In Israel, it is by far the most common and widespread Stomoxys species, and was found in every farm and pasture. In the lower parts of the country, especially the Coastal Plain and the Rift Valley, it was observed year-round. Above 700 m in the Mediterranean hills, the Golan Heights, and Mt. Hermon, it was absent or scarce from late November to early March. Stomoxys calcitrans was most abundant in dairy farms, farms raising calves, and horse stables. On some dairy farms they were more common than house flies, Musca domestica L. In Israel, S. calcitrans rarely bites humans in the vicinity of favored hosts, but in autumn, especially in small oases in arid southern Israel, it occasionally attacks humans for short periods (unpublished data of the authors). Also in the aforementioned locations, often tens of km from farms and suitable breeding sites, this species was frequently found feeding in large numbers on flowering bushes, especially Ochradenus baccatus Delile, Resedaceae, Prosopis farcta (Banks & Sol.), Mimosaceae, and the local Tamarix species.