Sand flies and other bloodsucking insects have been around for millions of years. They are known to have fed on dinosaurs, there are still reptile feeding sand flie around today. George and Roberta Poinar have studied fossil amber and found 100 million year old sand flies from amber created in the dinosaur era. These sand flies were found to contain Leishmania parasites in their proboscis; thus Leishmania might have plagued the dinosaurs and even helped force them into extinction.
A scientific paper giving more details of the technique of examining sand flies in dominicon amber is given in this link….