Five new fossil species of the Recent genus of blood-feeding sand flies Lutzomyia (Psychodidae: Phlebotominae) are described: L. filipalpis, L. miocena, L. paleopestis, L. schleei, and L. succini. All are preserved in Miocene amber from the Dominican Republic; today Hispaniola harbours only two known species of this genus. Recent Lutzomyia feed on a wide variety of terrestrial vertebrates, including reptiles, birds, and mammals. Three rare pieces of the amber are reported, two described in detail, which preserved assemblages of Lutzomyia swarms with strands of mammalian hair, indicating that at least some of the fossil species were mammal feeders. Microstructure of the fossil hair offers little diagnostic evidence, but is very similar to that of insectivores in the Solenodontidae. Further preserved evidence indicates that the fossil midges swarmed about an arboreal nest or site of decayed wood that was worked by a mammal, but at very specific times during formation of the amber. Other very rare Dominican amber pieces containing a flea and an ixodid tick also contain mammalian hairs of similar microstructure, together with Lutzomyia sandflies, possibly reflecting the ectoparasite community of a Miocene mammal. This parasitic association has implications regarding the evolution of vectors of mammalian pathogens like Leishmania and the study further reveals the extent of palaeobiological inference that is possible with amber.