General

Sand flies belong to the insect order Diptera, suborder Nematocera. Within this suborder the family Psychodidae includes biting sand flies in diverse genera. The subfamily Phlebotominae consists of about 700 phlebotomine species.  

Sand flies are small insects, approximately 1.2-3.7 mm in length (Perfiliev, 1968), and possess a hairy appearance. Fossil phlebotomines are about 120 million years old (Mehlhorn, 2001). 

Among the existing phlebotomine genera, two have been proven as vectors of one of the main zoonotic pathogens worldwide, the protozoan parasite Leishmania. These two genera are Phlebotomus in the Old World and Lutzomyia in the New World. 

Scanning electron microscopical image of adult sand fly (Phlebotomus spp.), frontal view 

Taxonomy

Sand flies belong to the class of Insecta. Among other characteristics, three body sections are typical of this class. 

As mosquitoes, sand flies are members of the suborder Nematocera. Both members can be recognized by their many segmented antennae, which are usually long. Most of the nematocerans are small, slender and long-legged, usually midge- or mosquito-like in appearance. Within the suborder Nematocera, many flies are of economic importance, as pests or even disease vectors.  

The suborder Nematocera is including midges, sand flies, black flies, mothflies, harlequin-flies and mosquitoes. Within this suborder, the family Phlebotominae / Psychodidae includes biting sand flies in diverse genera and non-biting owl-midges or moth flies in the genus Psychoda. The psychodids are small to minute, usually very hairy, moth-like flies that hold their wings roof-like over the body when resting. The adults occur in moist, shady places. Their larvae occur in decaying vegetable matter, mud, moss, or water. 

Of the about 700 phlebotomine sand fly species, only about 70 are anthropophagous. Phlebotomines are able to transmit viral, bacterial and parasite diseases (Mehlhorn, 2001).  

The number of genera within the subfamily Phlebotominae is depending on the hierarchical classification adopted, but only sand flies in the genera Phlebotomus (Old World) and Lutzomyia (New World) are proven vectors of Leishmania, though in other genera man-biting flies also occur. Diverse subgenera within the different genera exist.  

 

Classification of sand flies 

Phylum:  Arthropoda 
Class:  Insectea (= Insecta, Hexapoda) 
Order:  Dipterida (i.e. two-winged insects) 
Suborder:  Nematocera 
Family:  Phlebotomidae / Psychodidae 
Subfamily:  Phlebotominae 
Genus:  e.g., Phlebotomus, Lutzomyia 

Distribution

In the Old World, which is dominated by the genus Phlebotomus, sand flies tend to be more numerous in relatively dry zones. In the New World they favour the forests which cover much of the tropics. Thus they occur in warmer regions of temperate countries, e.g. Mediterranean countries, the Middle East, Africa, India and China, and in tropical countries. Of medical importance there, Lutzomyia species are especially common in forested areas of Central and South America. 

Of the genus Phlebotomus, the sand fly Ph. (Transphlebotomusmascittii Grassi, 1908, appears to be the most northerly species (Rioux et al., 1969).  

Epidemiology

Sand flies have a limited chance to find a host while the distance they can travel is short compared with some flies or even mosquitoes. They often move in short hops. Most of them remain within 20-30 cm of the soil surface. 

Whereas the maximum flight distance of Ph. ariasi in trials in France has been 2.3 km (Killick-Kendrick et al., 1984). Flight speed in Ph. ariasi was estimated to be around 1m/sec (Killick-Kendrick et al., 1986). 

Sand flies are usually not found at great altitudes but have been reported as vector of a form of dermal leishmaniosis at 2800 m (in Peru). Sand flies often stay close to the ground, but some American forests sand flies bite in the canopy, some at all levels or in a middle zone while following their hosts (Shaw et al., 1972). 

References

Introduction

Mehlhorn H: Sand flies. In: Mehlhorn H (ed.): Encyclopedic reference of parasitology. Biology, structure, function. 2nd edn., Springer Verlag, Berlin, 2001, 563-5 

Perfiliev PP: Fauna of U.S.S.R. Diptera. hlebotomidae sandflies). Acad. Sci. U.S.S.R. Zool. Inst. New Ser. No. 93, Vol. 3 No. 2, Israel Program for Scientific Translations, Jerusalem, 1968 

 

Taxonomy

Mehlhorn H: Sand flies. In: Mehlhorn, H. (ed.): Encyclopedic reference of parasitology. Biology, structure, function. 2nd edn., Springer Verlag, Berlin, 2001, 563-5 

 

Distribution

Rioux JA, Golvan YJ, Crosel H, et al.: Epidemiologie des leishmanioses dans le sud de la France. Monogr. Inst. nat. santé recherche méd. (INSERM) (Paris) 1969, no. 37 

 

Epidemiology

Killick-Kendrick R, Rioux JA, Bailly M, et al: Ecology of leishmaniasis in the south of France. 20. Dispersal of Phlebotomus ariasi Tonnoir, 1921 as a factor in the spread of visceral leishmaniasis in the Cévennes. Ann Parasitol Hum Comp. 1984, 59, 555-72 

Killick-Kendrick R, Wilkes TJ, Bailly M, et al: Preliminary field observations on the flight speed of a phlebotomine sandfly. Trans R Soc Trop Med Hyg. 1986, 80, 138-42 

Shaw JJ, Lainson R, Ward RD: Leishmaniasis in Brazil. VII. Further observations on the feeding habitats of Lutzomyia flaviscutellata (mangabeira) with particular reference to its biting habits at different heights. Trans R Trop Med ;Hyg. 1972, 66, 718-24

EXPLORE OUR CONTENT

CVBD Maps

The CVBD Occurence World Map presents country-specific situations based on current scientific knowledge and feed-back from experts around the world in an easy-to-grasped way.

Resources

Bayer Animal Health supports education in parasitology and especially in the field of Vector-Borne Disease.  Access picture and video collections, discover the World Forum calendar, interesting links and our glossary.

CVBD World Forum

The CVBD World Forum is a working group of leading international experts with the mission to enhance knowledge and communication on companion animal vector-borne diseases for the improvement of animal, human, and environmental health.