Psychodidae ppt

2.  Jimma university
 Addis Ababa university
 Hawassa university
 Haramaya university
 Gonder university
 American society of clinical pathology
 CDC

3.  Introduction to psychodidae
 Morphology of phlebotomine
 Life cycle of phlebotomine
 Adult behaviour
 Medical importance
 Control measures

4. At the end of this chapter, the student shall be able to:
 Understand the three types of leshimaniasis infection
 Describe the behavior of adult phlebotomine sand fly
 Point out very important differentiating features of
larva, pupa, and adult stage of phlebotomine sand
flies

5. Family : Psychodidae
Genus: Phlebotomus (Sand fly)
 3 sub generas:areolas
1. Phlebotomus (only in old world: semi – arid &
Savannah areas in preference to forests)
2. Lutzomyia (only in the new world tropics: in
forested areas of Central & South America)

6. 3. Sergentomyia (only in old world: especially
Indian Sub – region, also in Africa & Central
Asia)
 Only Phlebotomus and Lutzomyia are more
important b/c they suck blood & are vectors
of disease.
 A few species of Sergentomyia bite people,
but they are not disease vectors.

7.  Most important species:
 P. papatasi
 P. sergenti
 P. argentipes
 P. ariasi
 P. perniciosus
 L. longipalpis
 L. flaviscutellata complex

8.  Adult flies also called sand flies
(confusion????)
 In some parts of the world
ceratopogonidae and Black flies
(Simuliidae) are also called sand flies.
 No details are given for distinguishing
between the adults of Phlebotomus,
Lutzomyia and Sergentomyia.

9.  Pale (sandy) in color
 Very minute in size
 Body (head, thorax & abdomen) and
wings covered with dense long hairs

10.  Head carries:
◦ 2 dark big compound eyes
◦ 2 long antennae (16 segements) & similar in male
and female
◦ 2 maxillary palps (5 segments) bent over the
proboscis
◦ Short proboscis

11.  Thorax : humped (humpback) and carries
◦ 3 pairs of legs (long and slender)
◦ One pair of hairy wings (lanceolate in outline)
attached to the mesothorax
 Abdomen:
◦ Slender in the male with straight outline, ending
in a pair of claspers
◦ Bulging in the female with convex outline
ending in a pair of cerci

12. 2. Egg
 Elongate ovoid, dark and ornamented
 Minute; deposited in cracks, holes,
termite mounds/hills
 Laid singly (30 – 70 eggs at each
oviposition)

13. 3. Larva (4 instars): feed on organic matter
◦ Divided into head, thorax (3 segments) and
abdomen (9 segments)
◦ All segments including head carry serrated
(matchstick) hairs
◦ The abdomen has pseudopods
◦ The last abdominal segment carries 4 long bristles
(caudal setae)

14. 4. Pupa
 Composed of cephalothorax and abdomen
 The antenna has a long antennal sheath
 The larval skin is attached to the posterior
end
 Characteristic two pairs of caudal bristles

17. PHLEBOTOMINE PUPA WITH LAST LARVAL SKIN AND CAUDAL HAIR

20. Fertilized female
need blood for
egg development
The female lay
eggs in damp
areas, in cracks
or holes, in walls
or gound
Larva
comes
out
Larva moult
3 times
giving 4
larval
stages
(instars)
The 4th larva
moults to give
the pupa (moves
but does not
feed)
Adult
Male and
female
mate

21.  Only females feed on blood
◦ humans and other vertebrates
 Batting is usually restricted to crepuscular and
nocturnal periods but also in darkened rooms at
day time
 Most are exophagic but some are endophagic
 Adults are weak fliers, fly not more than few
hundred meters
 Air movement affects the activity of adult flies

22.  During the day adult flies rest in sheltered,
dark and humid sites
 Sensitive to temperature and are drawn to
human and other animals with high
temperature
 Have a characteristic hopping type flight
 Unable to bite through clothing's

23.  Leishmaniasis
 Sandfly fever or papatasi fever or three – day
fever: mild viral fever
 Oroya fever or Carrio’n’s disease or Peruvian
verruga in the new world: caused by Bartonella
bacilliformis
 Harara (in Middle East): allergic reaction to the
bite of sandfly
5.5. Medical importance

24. 5.6.Control:
 Filling cracks in walls and ground
 Screen and nets
 Insecticides against larvae and adults
 Repellents
e.g. Diethyltoluamide (DEET),
Dimethylphthalate (DIMP)
 Control of reservoirs such as rodents, dogs,
gerbils(Killing ???)

25.  There are three generas of Psychodidae (Phlebotomus,
Lutzomyia, and Sergentomyia)
 Adult flies are also called as sand fleis though there are
differences in naming the species in different localities
 They are very minute insects, wings covered with dense
long hairs, palps bent over proboscis and humped
thorax
 The eggs are dark and ornamented
 Larval control is almost impossible

26.  References
◦ Ibrahim A, Geme U, Melaku T, Jigssa G(2004 )
Lecture Note on Vector Biology for Medical
Laboratory Technologists. Addis Ababa
University,(Carter Center). Ethiopia
◦ William B. Herms's, Mauriece T. James, & Robert F.
Harwood. 1969 Medical Entomology
◦ Mike W. Service (1996). Medical Entomology for
Students, second edition
◦ D.S. Kettle (1984). Medical and Veterinary
Entomology