Sandfly


(Diptera: Psychodidae)

There are about 33 species of sand flies in India, some of which are known to transmit diseases. They are smaller than mosquitoes. Wings are rhomboidal in shape, narrow at both ends; hairy and held vertically up over the abdomen. Wing venation is characteristic of sand flies having 8 longitudinal veins. They move by hopping action. Antenna is 16 jointed and whorl plumose and there is no difference in the antennae of males and females.

Female mouth parts are of piercing and sucking type while male mouth parts are poorly developed and adapted for sucking nectar and fruit juices. Legs are long and slender adapted for hopping movement. Ninth and tenth abdominal segments are modified as genitalia. Male genitalia have prominent superior and inferior claspers and median lamellae and aedeagus. Adults can bite through the mosquito netting as they are small in size and can easily squeeze through the holes of mesh.

LIFE CYCLE

Eggs are laid in moist soil with organic matter and aeration. Breeding places include backyard of houses, cattle sheds, crack and crevices in houses with accumulated moisture and organic matter. Eggs are whitish, torpedo shaped, with striations on the surface, gradually turning darker as the embryo develops. Incubation period is 6-9 days.

Larva is apodous, hairy maggot, without eyes and with a pair of sharp mandibles. Apex of abdomen has a tube like stigmata or respiratory spiracle on the ventral side. Tip of abdomen has a pair of long and a pair of short caudal bristles, which are kept erect while walking. Body is covered with rows of spines. Full grown larva is 5 mm long. There are 5 larval instars and the larva can go up to one foot in soil during development. Total larval period is 21-28 days.

Pupa has cephalothorax and abdomen that is curved upwards. It is a dormant stage that does not feed but is mobile and comes to the surface before emergence of the adult. Pupal period is about 10 days. Complete life cycle takes 37-47 days.

Diseases transmitted by sand flies.

Disease name

Causative organism

Sandfly species

Distribution

Kala-azar

Oriental Sore

Sandfly fever

Espundia (naso-

Pharyngeal leish-maniasis

Carrion’s disease

Leishmania donovani

Leishmania tropica

Virus

Leishmania braziliensis

Bartonella bacilliformis

Phlebotomus argentipes

P. sergenti; P. papatasii

Phlebotomus papatasii

P. intermedius

P. varrucarum

NE India, TN

C & N India

Whole India

S. America

S. America

CONTROL

Dusting or spraying of houses with BHC, malathion, endosulfan, carbaryl etc. kills the adults and other stages. Cleanliness in houses and surroundings and plastering of cracks and crevices also reduces adult population. Cleanliness in breeding places and treatment of these places with insecticides is an effective control measure. Larvae are difficult to control since they burrow deep into the soil but burying the garbage dumps and treatment with insecticides helps in controlling them.




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