The objective of the trials is to investigate the associations between the virus and vector that are involved in the transmission of a virus from a contaminated host to a healthy one. The study generally involves one or all of the following procedures: first, a non-viruliferous vector is placed on an infector plant after fasting to obtain the virus for a specified acquisition access period. During this period, a part of the time may be used for probing, while the remaining time is the acquisition feeding time. After this, the vector becomes viruliferous, and it can either be instantly infectious or experience a delay, referred to as the latent period or pre-infective period, in which the vector remains non-infectious. The experiment may require post-acquisition fasting before introducing the vector to a healthy test host, where inoculation feeding can take place during a specified inoculation access period. In a serial transmission test, a single acquisition access period is followed by inoculation feeding on two or more test hosts in succession.