Blackbirds T urdus merula as competent reservoirs for B orrelia turdi and B orrelia valaisiana in P ortugal: evidence from a xenodiagnostic experiment

Summary To confirm that thrushes, such as blackbirds T urdus merula , play a role as reservoir for some B orrelia genospecies, we performed a xenodiagnostic experiment with blackbirds captured in a mixed wood located in W estern P ortugal where B orrelia turdi , an uncommon genospecies in E urope, was the most prevalent genospecies associated with birds. Two out of five birds harboured B . turdi infected I xodes frontalis at the time of capture. Four out of five birds transmitted spirochaetes to I xodes ricinus xenodiagnostic ticks: two birds transmitted B orrelia valaisiana to 25.7% and 10.5% of ticks, and two transmitted B . turdi to 6.4% and 5.4% of ticks. Our results showed that blackbirds transmit B . valaisiana and B . turdi to I . ricinus feeding larvae, acting as reservoir hosts for these genospecies in nature.