The biology of each species of sand fly is unique and complex, covering all aspects of reproduction, feeding, dispersal and other activities, being of importance for epidemiology of transmitted diseases and vector control (WHO, 1990).
Sand flies undergo complete metamorphosis, passing through four distinct stages during their life cycle: egg, larvae, pupa, adult / imago.
In arid and temperate regions, larvae may remain in a state of diapause for many months. In temperate countries, sand flies over-winter as eggs or larvae in a so-called diapause. For this reason, adults can appear early in summer, and leishmaniosis – as one the sand fly-borne diseases – can exist in places with a cold winter (Lewis, 1971). Similarly, diapause might also be the means by which many tropical sand flies survive periods of drought or heavy rain (Ward and Killick-Kendrick, 1974).
Palaearctic sand flies over-winter as fourth instar larvae (Killick-Kendrick and Killick-Kendrick, 1987).From laboratory studies, a complete gonotrophic cycle is normally not less than 6 weeks, but can differ between different species (Killick-Kendrick and Killick-Kendrick, 1999).