Nematocera (ceratopogonidae, psychodidae, simuliidae and culicidae) and control methods

The biology, veterinary importance and control of certain Nematocera are described and discussed. Culicoides spp. (family Ceratopogonidae) transmit the arboviruses of bluetongue (BT), African horse sickness (AHS), bovine ephemeral fever (BEF) and Akabane. Some other arboviruses have been isolated from these species, while fowl pox has been transmitted experimentally by Culicoides. These insects are vectors of the parasitic protozoans Leucocytozoon caulleryi and Haemoproteus nettionis, and the parasitic nematodes Onchocerca gutturosa, O. gibsoni and O. cervicalis. They also cause recurrent summer hypersensitivity in horses, ponies, donkeys, cattle and sheep. Farm animals can die as a result of mass attack by Simulium spp., which are also vectors of Leucocytozoon simondi, L. smithi and the filariae O. gutturosa, O. linealis and O. ochengi. Venezuelan equine encephalomyelitis (VEE) and Rift Valley fever (RVF) have been isolated from simuliids, and vesicular stomatitis virus New Jersey strain has been replicated in Simulium vittatum. Simuliids are well known as vectors of O. volvulus, the cause of human onchocercosis (river blindness). The family Psychodidae includes the genera Phlebotomus and Lutzomyia (subfamily Phlebotominae), vectors of Leishmania spp. in humans, dogs and other mammals. Vesicular stomatitis virus Indiana strain has been regularly isolated from phlebotomine sandflies. Mass attack by mosquitoes can also prove fatal to farm animals. Mosquitoes are vectors of the viruses of Akabane, BEF, RVF, Japanese encephalitis, VEE, western equine encephalomyelitis, eastern equine encephalomyelitis and west Nile meningoencephalitis, secondary vectors of AHS and suspected vectors of Israel turkey meningoencephalitis. The viruses of hog cholera, fowl pox and reticuloendotheliosis, the rickettsiae Eperythrozoon ovis and E. suis, and the bacterium Borrelia anserina are mechanically transmitted by mosquitoes. These insects also induce allergic dermatitis in horses. They transmit several filarial worms of both animals and humans, and are of great medical importance as vectors of major human diseases, including malaria, yellow fever, dengue fever and many more diseases caused by arboviruses.