The competence of a Frankliniella occidentalis and a Thrips tabaci population to transmit @entity57570 ) was analysed. Adults of the F. occidentalis population transmitted this virus efficiently, whereas those of the thelytokous T. tabaci population failed to transmit. @entity57570 replicated in the midgut of the larvae of both populations after ingestion of virus; however, lower amounts accumulated in T. tabaci larvae than in F. occidentalis larvae. The virus was almost undetectable in T. tabaci adults, whereas high titres were readily detected in the F. occidentalis adults. The first @entity281 in F. occidentalis larvae were detected by immunocytochemical studies in midgut epithelial and subsequently in midgut muscle cells, the ligaments, and finally in the salivary glands. The @entity281 were weaker in the midgut epithelial and muscle cells of T. tabaci larvae, followed by an almost complete absence of any @entity281 in the ligaments, and a complete absence in the salivary glands. Studies by electron microscopy revealed the budding of some virus particles from the basal membrane of midgut epithelial cells of F. occidentalis larvae into the extracellular space of the basal labyrinth. Enveloped virus particles were also seen in midgut muscle cells of F. occidentalis larvae. They were not discerned in epithelial and muscle cells of T. tabaci larvae and adults. This study showed that the rate of virus replication in the midgut and the extent of virus migration from the midgut to the visceral muscle cells and the salivary glands are probably crucial factors in the determination of vector competence.

Factors determining vector competence and specificity for transmission of XXXX .

@entity281 :: ('MESH:D007239', 'Disease') :: ['infections', 'infection'] @entity57570 :: ('11613', 'Species') :: ['TSWV', 'Tomato spotted wilt virus (TSWV']
@entity57570 :: (11613,Species) :: ['Tomato spotted wilt virus']
