Fig. 1

Emergence of infective third-stage larvae (L3) from the tip of the mosquito proboscis. During blood-feeding, a subpopulation of L3 in the labial sheath of the proboscis emerge from the proboscis, alighting on the skin of the host in a drop of the mosquito hemolymph (eL3). It is estimated that only approximately 10% of the eL3 survive on the skin and penetrate into it [26]; the fate of the L3 that do not emerge during blood-feeding is not known. Emergence from the proboscis typically occurs at the labellum or distal portion of the labial sheath and can be triggered by sensation of a thermal cue (red gradient). Other cues may also play a role, such as chemical compounds released by the host (green gradient) or a sensation of mechanical forces caused by the deformation of the labial sheath (orange gradient), which slides backward as the fascicle is inserted into the host skin. Adapted from Bancroft [36]