Transovarial transmission

Transovarial transmission occurs in certain arthropod vectors as they transmit disease-causing bacteria from parent arthropod to offspring arthropod. For instance, Rickettsia rickettsii, carried within ticks, is passed on from parent to offspring tick by transovarial transmission. In contrast, Rickettsia prowazekii is not passed on by transovarial transmission because it kills the vector that carries it (human louse). This is the mechanism by which many Rickettsiae are maintained in their arthropod hosts through generations.