Sex-specific influences of Frankliniella occidentalis (Western Flower Thrips) in the transmission of Tomato Spotted Wilt Virus (Tospovirus)

摘要

The tospovirus-plant-vector interaction is a specific and complex relationship. It is established that several factors influence this interaction leading to high variability of transmission efficiency of the virus within a vector population. We studied the contribution of vector gender to this interaction using Frankliniella occidentalis (western flower thrips) reared on either Tomato spotted wilt virus (TSWV) infected or uninfected Capsicum annum leaflets throughout their larval stages. Later pupae were individually transferred onto healthy leaf disks to examine the differences in: survival, development rate, transmission efficiency and feeding behavior between males and females in all the treatments. This was based on the hypothesis that sex of the vector influences transmission efficiency within the vector population. Our results showed that males had significantly higher longevity, lower mortality and shorter development time compared to females, while in the comparison of feeding behaviour, females were found to feed more intensively than males, regardless of whether they were exposed or unexposed to TSWV. Conversely, transmission efficiency; which referred to successful inoculation and establishment of the virus in the host plant after a given period of inoculative feeding, was found to be significantly higher in males compared to females, despite females having the highest percentage of transmitting individuals. These findings account in part for the high variability in vector competence of F. occidentalis within a population, which further give insight into the biological factors that may influence the transmission of TSWV by F. occidentalis.