Larval Development of Dirofilaria immitis (Leidy) in Fleas

In most instances the transmission of this worm by any particular vector is correlated with the ability of the prelarval3 microfilaria to develop to the infective stage. The theory of mosquito transmission of canine filariasis has been considered so firmly established since Grassi and Calandruccio (1890) observed developmental forms of Dirofilaria immitis larvae in Anopheles maculipennis, that the search for other arthropod vectors has been largely neglected. Laboratory tests have demonstrated that more than 26 species of mosquitoes have been experimentally infected with D. immitis larvae.