Fig. 1

Experimental design for testing host detection probabilities in ticks. In step 1, unfed larvae were fed on sheep or chicken blood. Engorged larvae were then maintained under standard laboratory conditions until the moult. One half of the newly moulted nymphs were kept for host detection analysis. In step 2, the other half of unfed nymphs from step 1 were again fed using the artificial feeding system with four treatment types: nymphs fed as larvae on one host blood type were either fed again on the same blood type (blood meal treatments “sheep-sheep” and “chicken-chicken”) or on a different blood type (blood meal treatments “sheep-chicken” and “chicken-sheep”). Fully-engorged nymphs that detached from the membrane were kept under standard laboratory conditions until the moult into the adult life stage. The sample sizes of ticks analysed for host use are indicated for each treatment. Blue represents chicken blood meal and green sheep blood meal. L = larval blood meal, > N = nymphal blood meal