[Arbovirus-vector relations].

The arbovirus-vector relationships result from several successive phenomena: infection of the vector, replication and dissemination of the virus inside the arthropod, transmission to the vertebrate. We propose to call "competency" the entirety of these relationships particular to specific viral and arthropod populations, the adaptation of which it characterizes. By "vectorial capacity", we must designate the competency and the effect exerted on it by environmental factors.