''Phlebotomus'' is a
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of "
sand flies
Sandfly or sand fly is a colloquial name for any species or genus of flying, biting, blood-sucking dipteran (fly) encountered in sandy areas. In the United States, ''sandfly'' may refer to certain horse flies that are also known as "greenhead ...
" in the
Diptera
Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advance ...
family
Psychodidae
Psychodidae, also called drain flies, sink flies, filter flies, sewer flies, or sewer gnats, is a Family (biology), family of Fly, true flies. Some genera have short, hairy bodies and wings, giving them a "furry" moth-like appearance, hence one ...
. In the past, they have sometimes been considered to belong in a separate family,
Phlebotomidae
Psychodidae, also called drain flies, sink flies, filter flies, sewer flies, or sewer gnats, is a family of true flies. Some genera have short, hairy bodies and wings, giving them a "furry" moth-like appearance, hence one of their common names, ...
, but this alternative classification has not gained wide acceptance.
Epidemiology
In the
Old World
The "Old World" () is a term for Afro-Eurasia coined by Europeans after 1493, when they became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia in the Eastern Hemisphere, previously ...
, ''Phlebotomus'' sand flies are primarily responsible for the transmission of
leishmaniasis
Leishmaniasis is a wide array of clinical manifestations caused by protozoal parasites of the Trypanosomatida genus ''Leishmania''. It is generally spread through the bite of Phlebotominae, phlebotomine Sandfly, sandflies, ''Phlebotomus'' an ...
,
[ an important parasitic disease, while transmission in the ]New World
The term "New World" is used to describe the majority of lands of Earth's Western Hemisphere, particularly the Americas, and sometimes Oceania."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: ...
, is generally via sand flies of the genus ''Lutzomyia
''Lutzomyia'' is a genus of Phlebotominae, phlebotomine Sandfly, sand flies consisting of nearly 400 species, at least 33 of which have medical importance as Vector (epidemiology), vectors of human disease. Species of the genus ''Lutzomyia'' are ...
''. The protozoa
Protozoa (: protozoan or protozoon; alternative plural: protozoans) are a polyphyletic group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic debris. Historically ...
n parasite
Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...
itself is a species of the genus ''Leishmania
''Leishmania'' () is a genus of parasitic protozoans, single-celled eukaryotic organisms of the trypanosomatid group that are responsible for the disease leishmaniasis. The parasites are transmitted by sandflies of the genus '' Phlebotomus'' ...
''. Leishmaniasis normally finds a mammalian reservoir in rodents
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are n ...
and other small animals such as canids
Canidae (; from Latin, ''canis'', "dog") is a biological family of caniform carnivorans, constituting a clade. A member of this family is also called a canid (). The family includes three subfamilies: the Caninae, and the extinct Borophaginae ...
(canine leishmaniasis
Canine leishmaniasis (LEESH-ma-NIGH-ah-sis) is a zoonotic disease (see human leishmaniasis) caused by ''Leishmania'' parasites transmitted by the bite of an infected phlebotomine sandfly. There have been no documented cases of leishmaniasis trans ...
) and hyraxes
Hyraxes (), also called dassies, are small, stout, thickset, herbivorous mammals in the family Procaviidae within the order Hyracoidea. Hyraxes are well-furred, rotund animals with short tails. Modern hyraxes are typically between in length a ...
. The female sand fly carries the ''Leishmania'' protozoa from infected animals after feeding, thus transmitting the disease, while the male feeds on plant nectar.
The parasite ''Leishmania donovani
''Leishmania donovani'' is a species of intracellular parasites belonging to the genus ''Leishmania'', a group of haemoflagellate kinetoplastids that cause the disease leishmaniasis. It is a human blood parasite responsible for visceral leishm ...
'' is the main causative agent of visceral leishmaniasis
Visceral leishmaniasis (VL), also known as kala-azar (Hindi: kālā āzār, "black sickness") or "black fever", is the most severe form of leishmaniasis and, without proper diagnosis and treatment, is associated with high fatality. Leishmaniasi ...
(VL) in India, Nepal, and Bangladesh, where it is transmitted by the sand flies of the species ''Phlebotomus argentipes''. This species of sand flies was on the brink of elimination in India during the 1960s following the widespread use of DDT
Dichlorodiphenyltrichloroethane, commonly known as DDT, is a colorless, tasteless, and almost odorless crystalline chemical compound, an organochloride. Originally developed as an insecticide, it became infamous for its environmental impacts. ...
for malaria
Malaria is a Mosquito-borne disease, mosquito-borne infectious disease that affects vertebrates and ''Anopheles'' mosquitoes. Human malaria causes Signs and symptoms, symptoms that typically include fever, Fatigue (medical), fatigue, vomitin ...
control. However, there was a resurgence in their population a decade later.
''Phlebotomus'' species are also vector
Vector most often refers to:
* Euclidean vector, a quantity with a magnitude and a direction
* Disease vector, an agent that carries and transmits an infectious pathogen into another living organism
Vector may also refer to:
Mathematics a ...
s for bartonellosis
Bartonellosis is an infectious disease caused by bacteria of the genus '' Bartonella''. '' Bartonella'' species cause diseases such as Carrión's disease, trench fever, cat-scratch disease, bacillary angiomatosis, peliosis hepatis, chronic bac ...
, verruga peruana, and pappataci fever
Pappataci fever (also known as phlebotomus fever and, somewhat confusingly, sandfly fever and three-day fever) is a vector-borne febrile arboviral infection caused by three serotypes of Phlebovirus. It occurs in subtropical regions of the Eas ...
, an arboviral disease caused by sandfly fever viruses such as the Naples and Sicilian strains of the genus ''Phlebovirus
''Phlebovirus'' is a genus of viruses in the family '' Phenuiviridae'' in the order '' Hareavirales''. The genus contains 67 species. It derives its name from Phlebotominae, the vectors of member species Sandfly fever Naples virus, which is sa ...
'' (family ''Bunyaviridae
''Bunyaviricetes'' is a class of segmented negative-strand RNA viruses with mainly tripartite genomes. Member viruses infect arthropods, plants, protozoans, and vertebrates. The name ''Bunyaviricetes'' derives from Bunyamwera, where the virus B ...
''), which also includes the closely related Toscana virus.
In Egypt, two species of medical importance are ''Phlebotomus papatasii'' and ''P. langerni''. These flies are short-lived. Females are bloodsuckers at night; males feed on plant juices. Adults are poor fliers, they usually hop for short distances.
Morphology
Adults are about 1.5–3.0 mm long and yellowish in colour, with conspicuous black eyes, and hairy bodies, wings, and legs. The oval lanceolate wings are carried erect on the humped thorax.
Males possess long prominent genital terminalia known as claspers.
Females have a pair of anal recti.
Lifecycle
Batches of thirty to seventy eggs are laid in cracks and holes in the ground, in crevices in masonry and among leaf litter. The eggs require a humid environment to avoid desiccation, and hatch within about twenty days. The larva
A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...
e are mainly scavenger
Scavengers are animals that consume Corpse decomposition, dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a he ...
s, consuming fungi
A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...
, leaf mould, rotting vegetation and detritus
In biology, detritus ( or ) is organic matter made up of the decomposition, decomposing remains of organisms and plants, and also of feces. Detritus usually hosts communities of microorganisms that colonize and decomposition, decompose (Reminera ...
. The larvae are recognisable by their black heads, greyish twelve segmented bodies and conspicuous feathery, branching bristles on head and body, and two pairs of long hairs on the tip of the abdomen. The larvae pass through four instar
An instar (, from the Latin '' īnstar'' 'form, likeness') is a developmental stage of arthropods, such as insects, which occurs between each moult (''ecdysis'') until sexual maturity is reached. Arthropods must shed the exoskeleton in order to ...
s over the course of three to four weeks, before selecting an upright position and pupa
A pupa (; : pupae) is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their life cycle, the stages th ...
ting, with the final larval skin remaining attached to the pupa, the long hairs protruding. In cooler climates, the larvae may diapause
In animal dormancy, diapause is the delay in development in response to regular and recurring periods of adverse environmental conditions.Tauber, M.J., Tauber, C.A., Masaki, S. (1986) ''Seasonal Adaptations of Insects''. Oxford University Press It ...
over winter. Adults emerge from the pupae after about one to two weeks. The whole cycle takes thirty to sixty days unless the larvae diapause, when it may take four or five months. Laboratory colonies of several ''Phlebotomus'' species have been established for experimental study of their biology, behaviour, mutual relations with disease agents, and for testing methods of vector control.[ ]
Behaviour
The adult flies are nocturnal, spending the day sheltering in dark humid places such as on bark, among foliage, among leaf litter, in animal burrows, in termite mounds, and in cracks and crevices. At nightfall they emerge to feed on sugary secretions and plant sap. The female needs a blood meal before it can reproduce; some species feed on mammals including humans, while others also feed on birds, reptiles and amphibians. The fly is a weak flier and takes short flights to find a victim, adopting a "hopping" style of flight when close to a host. Some sandflies are "exophagic", living entirely out of doors, while others are "endophagic" and invade houses. In the tropics, adults may breed all year round, but in temperate climates the adults die off in the autumn and new adults emerge in the spring. The adults have short mouthparts and are unable to bite through clothing.[
]
References
External links
*
{{Authority control
Psychodidae
Diptera of Africa
Diptera of Asia
Nematoceran flies of Europe
Nematocera genera
Insect vectors of human pathogens
Insects of North Africa
Insects of the Middle East
Insects of Southeast Asia
Fauna of the Afrotropical realm
Fauna of the Indomalayan realm
Taxa named by Camillo Rondani