Sandfly (or sand fly) is a colloquial name for any species or genus of flying, biting, blood-sucking Dipteran encountered in sandy areas. In the United States,sandfly may refer to certain horse flies that are also known as “greenheads” (family Tabanidae), or to members of the family Ceratopogonidae, also known inFlorida and elsewhere as a sand gnat, sandflea, no-see-um (no-see-em, noseeum), granny nipper, chitra, punkie, or punky. Outside the United States,sandfly may refer to members of the subfamily Phlebotominae within the Psychodidae. Biting midges (Ceratopogonidae) are sometimes called sand flies or no-see-ums (no-see-em, noseeum). New Zealand sandflies are in the Austrosimulium genus, a type of black fly.
While horse flies are large flies, noseeums (sandfleas) and some Old-World sandflies are tiny midges. Sandfly bites may leave large, red itchy bumps that may turn into a rash. These bumps are frequently several times as itchy as mosquito bites, and tend to last longer as well.
In the various sorts of sandfly only the female is responsible for biting and sucking the blood of mammals, reptiles and birds. She requires the protein in the blood to make her eggs.
Some sandfly genera of the Phlebotominae subfamily are the primary vectors of leishmaniasis and pappataci fever; both diseases are confusingly referred to as sandfly fever. In the New World, leishmaniasis is spread by sand flies of the genus Lutzomyia; in the Old World, the disease is spread by sandflies of the genus Phlebotomus. Belize and Honduras are notorious in the Caribbean for their sandfly populations and travel pages frequently warn tourists to bring bug spray containing high concentrations of DEET… go here Courtesy of Wikipedia