Musca (Eumusca) autumnalis De Geer, 1776

Dawah, Hassan A., Abdullah, Mohammed A. & Deeming, John C., 2020, The Muscidae (Diptera) of Saudi Arabia, descriptions of two new species, new records and updated list of species, Zootaxa 4869 (1), pp. 1-54 : 12

Musca (Eumusca) autumnalis De Geer, 1776

Musca autumnalis De Geer 1776: 83

Distribution. This species was recorded from Saudi Arabia by El-Hawagry et al. (2016). It was described from Sweden. In the Middle East it was recorded from Turkey ( Pont et al. 2005).

Taxonomic remarks. This species is closely related to the house fly but is slightly larger, it is 7–8 mm long and grey in colour with four dark stripes on the thorax, and a grey-black patterned abdomen ( Gregor et al. 2002).

Biological remarks. It is a non-biting fly. The larvae feed on manure juices and plant sugars. Adults feed during the day on secretions around the eyes, mouth and nostrils on cattle and horses ( Gregor et al. 2002). It is considered a pest species, as it transmits eyeworm Thelazia spp. ( Spirurida : Thelaziidae ) to cattle and horses, and pinkeye (conjunctivitis) in cattle. The latter is an infection of the surface of the eye by the bacteria Moraxella bovis as a result of irritants by pollen grain or dust scratching the cornea of the eye which increases the secretion of tears from the eye. This then attracts M. autumnalis to feed on the tears, which spreads M. bovis that causes pinkeye in cattle ( Krafsur & Moon 1997; Giangaspero et al. 2004; Pont et al. 2005). Bradbury et al. (2018) reported a case of Thelaziasis in the eye of a 26 year old women where 14 worms of T. gulosa (Railliet & Henry) were found to have been transmitted by this species. There is a record that this species has also caused myiasis in cattle ( Gilarriortua 2015).