Insects belonging to the family Psychodidae in the order Diptera include numerous species of true flies, many of which are pests that are commonly referred to as “drain flies,” “sewer gnats,” and “moth flies.” The family Psychodidae also includes sand fly species in the genus Lutzomyia from the subfamily Phlebotomine. Sand fly species in this genus pose a major public health threat in Latin America where airborne pests transmit several viral, bacterial, and protozoal disease-causing microorganisms to humans. According to the Centers for Disease Control and Prevention, sand flies have been a growing public health threat in the US since the first case of sandfly-transmitted Leishmaniasis was contracted by a dog in New Jersey back in 1980. Since then dogs, foxes, and eventually, humans in the southeastern US have contracted the disease from biting sandflies, and Leishmaniasis is now considered a neglected disease. Sandflies frequently infest homes where they inflict bites to humans and pets, and infestations located near known Leishmaniasis reservoirs like infected animals require urgent pest control attention.

More than 700 sandfly species have been documented worldwide, 70 of which are known to transmit disease. The three sandfly species in the US that are capable of carrying and transmitting disease to humans include Lutzomyia anthophora, L. diabolica, and L. shannoni, and these three species are largely limited to a southeastern habitat range. Sandflies are easy to recognize due to their noticeably hairy wings that can be seen forming a “V” shape above their moth-like body. Lutzomyia shannoni is responsible for most cases of disease transmission in the US, and the species can only be found in Latin America and the southeast US from Florida to east Texas as well as Arkansas, Tennessee and the Carolinas.

All local human Leishmaniasis cases have been reported from east Texas and Oklahoma, and most US cases were transmitted while the victims were vacationing in the tropics. However, it is important to keep in mind that Texas is the only state where Leishmaniasis cases are legally required to be reported, and public health professionals believe that human and animal cases of Leishmaniasis are increasing rapidly in other southeastern states where medical professionals may not be familiar with the disease’s symptoms. Because of this, a vaccine is currently being fast-tracked by US medical researchers. Pest control professionals treat homes for sandfly infestations by applying residual pyrethroid insecticides to indoor surfaces and concealed spaces like wall voids.

Have you ever encountered a sand fly in your home?