Transmission of tomato yellow leaf curl geminivirus by Bemisia argentifolii (B. tabaci biotype B)
The transmission of an Egyptian isolate of tomato yellow leaf curl geminivirus by Bemisia argentifolii (B. tabaci biotype B) (both EPPO A2 quarantine pests) has been studied in Wisconsin (US). The virus can be transmitted with one adult B. argentifolii per tomato plant, but the efficiency of transmission increased fourfold when the number of adults was increased to five per plant (a maximum efficiency of 97 % was reached with 20 adults per plant). Tomato yellow leaf curl geminivirus is transmitted after a minimum acquisition-access period of 15 min (the maximum rate of transmission is reached after 24 h of acquisition period) and a minimum inoculation-access period of 15 min (the rate of transmission then increased and reached its maximum after 12 h of inoculation-access period). It was also shown that adults of B. argentifolii are unable to transmit the virus until 24 h after the initiation of the acquisition-access period regardless of the length of acquisition provided. The authors felt that this period of 24 h includes the acquisition-access period and the latent period during which the virus probably circulates within the vector. In addition, it was also shown that nymphs could acquire the virus. The authors pointed out that the fact that the virus is retained from nymphal to adult stage give support for a circulative mode of transmission. Finally, data on the virus titer within B. argentifolii indicate that there is a multiplication of tomato yellow leaf curl geminivirus in the insect vector.
Sources
Mehta, P.; Wyman, J.A.; Nakhla, M.K.; Maxwell, D.P. (1994) Transmission of tomato yellow leaf curl geminivirus by Bemisia tabaci (Homoptera: Aleyrodidae).
Journal of Economic Entomology, 87 (5), 1291-1297.