It is believed that haematophagy arose independently at least six times among the arthropods of the Jurassic and Cretaceous periods (145–65 million years ago) (Balashov, 1984; Ribeiro, 1995). The very patchy nature of the insect fossil record means that discussion of the evolution of the blood-sucking habit has until now relied heavily on detective work, with the major clues lying in the diversity of forms and lifestyles seen in modern-day insects, and in some cases in the details of their relationships with vertebrates. From careful interpretation of this evidence quite credible accounts of the likely evolution of the blood-sucking habit can be made. From this starting point it has been convincingly argued that the evolution of the blood-sucking habit in insects has occurred on several occasions, in each case along one of two main routes (Waage, 1979), and these are discussed below. Insect molecular systematics is beginning to emerge from its ‘Tower of Babel’ stage (Caterino et al., 2000) and it will make a major contribution in defining the detail of the evolutionary routes taken by haematophagous insects (Esseghir et al., 1997; Hafner et al., 1994; Lanzaro et al., 1998; Mans et al., 2002; Sallum et al., 2002). The proposed population bottleneck suffered by phlebotomines in the late Pleistocene and the subsequent radiation of the species out from the eastern Mediterranean sub-region is a good example of what we can expect (Esseghir et al., 1997).