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Poster: Epidemiology: Pathogen-Vector Interations


Variation in transmission of Tomato spotted wilt virus (TSWV) from Thrips tabaci is not solely influenced by virus titer within individual thrips
J. BROWN (1), A. Jacobson (2), G. Kennedy (1), S. Lommel (1), T. Sit (1) (1) North Carolina State University, U.S.A.; (2) Auburn University, U.S.A.

Thrips tabaci, a vector of TSWV, has been shown to vary greatly in the ability to transmit different isolates of TSWV. The objective of this study is to determine if the virus titer in individual T. tabaci influences the variation in transmission of TSWV from established T. tabaci isofemale lines collected from several locations in North Carolina. The isofemale lines were previously shown to differ in their ability to transmit various TSWV isolates collected from the same series of locations as the thrips. The virus-thrips line combinations were grouped in sympatric and allopatric pairings and the groups classified as low, moderate, or high transmitters based on the percent transmission of TSWV to Emilia sonchifolia leaf discs. Quantitative real-time PCR was done on T. tabaci from 12 selected virus-thrips line combinations to quantify virus titer in transmitting and nontransmitting individuals to determine if the variation in transmission was correlated with virus titer. The results show that variation in transmission efficiency of the different virus-thrips pairings are not explained by differences in virus titer within the thrips. This is in contrast to findings with other TSWV thrips vectors where virus titer was directly correlated with transmission efficiency. This suggests that the differences in transmission among these thrips-virus isolate pairings may be determined by the genetics of both the virus and the thrips, and their interaction.