Fig. 1

Diagrams of experimental designs. a Cat fleas were exposed to an infectious bloodmeal for 1, 3, 6 or 12 h, and then divided into feeding capsules containing naïve cat fleas for 24 h (exposure bioassays); b Cat fleas were exposed to an infectious bloodmeal for 24 h and then divided into feeding capsules containing naïve cat fleas for 1, 3, 6 or 12 h (association bioassays); c Whatman™ FTA cards were placed in flea cages after 24 hpe to an R. felis-infected bloodmeal. Cat fleas either had access to blood or the bloodmeal was removed for the duration of the experiment; d Cat fleas were exposed to an “infectious” bloodmeal containing fluorescent latex beads for 24 h, and then were placed with naïve fleas for 24 h