Interactions between a spider mite and a virus revealed via effects on their host plant.

Coinfection, when hosts are infected with more than one parasite, can modify life-history traits of both parasites and their host. We investigated reciprocal interactions between tomato spotted wilt virus (TSWV) and a non-vector spider mite, Tetranychus urticae, in coinfections on tomato plants. We compared the number of T. urticae daughters and adults and the viral load for two TSWV isolates (France81, which is more virulent, and LYE1137vir) in single and coinfections, and measured host traits (height, fresh weight, chlorophyll content, and number of flowers). TSWV infection reduced plant height, weight, flowers and chlorophyll content, especially when infected with isolate France81. T. urt