Thelazia-callipaeda
Guides
Phortica
Phortica is a genus of small flies in the family Drosophilidae, subfamily Steganinae. Several species are medically significant as biological vectors of the zoonotic eyeworm Thelazia callipaeda, which causes ocular infections in humans, domestic animals, and wildlife. The genus includes at least five species in Europe and the Middle East, with P. variegata and P. okadai being the best-documented vectors. These flies exhibit unusual zoophilic feeding behaviors, including lachryphagy (tear-feeding) in adult males of some species. The genus has gained increasing attention due to climate-driven range shifts and expanding transmission of thelaziosis.
Phortica variegata
variegated fruit fly
Phortica variegata is a small vinegar fly in the family Drosophilidae, distinguished by its unusual zoophilic behavior. Unlike most drosophilids, adult males feed on the lacrimal secretions (tears) of mammals, including humans, dogs, foxes, and other carnivores. This lachryphagous behavior makes it the primary European vector of Thelazia callipaeda, a zoonotic eyeworm that causes ocular infections in mammals. The species is native to Europe and has been introduced to the United States, where it has demonstrated vector competence for the parasite. Climate change is projected to alter its distribution significantly, with suitable habitats shifting toward Mediterranean coastal regions while declining in central-southern-eastern European transitional areas.