Public Health Vectors and Pests

Sand fly

 
Common Name Sandfly

Scientific Name Female Phlebotominae
Size 8.5mm in length
Colour Sandfly has a brownish colour during the day, it has hairs that are close to each other that coat it.
Description The wings are “V” shaped. The two wings have dense hairs and increases pigmentation patterns. The large compound eyes are more or less contiguous above the bases of the 15-segmented antennae. The pedicel of the males' antennae houses the Johnston's organ. The mouthparts are well-developed with cutting teeth on elongated mandibles in the proboscis, adapted for blood-sucking in females, but not in males. The thorax extends slightly over the head, and the abdomen is nine-segmented and tapered at the end.
 
Habitat They often lodge in shrubs or the thick layer of dead leaves that naturally covers the ground. Most no-see-ums can’t fly more than106.68m from their breeding area, so if they are causing a problem one can be able to run away from them.
Commonly found at beaches, wetlands creek and lakebeds, it is believed that sand fly stays within 106.68 meters of its breeding ground.
 
Lifecycle Different from most biting Diptera, sand fly has a terrestrial development rather than aquatic. Although there have been relatively few successful attempts to identify breeding sites in nature, eggs are laid in soil rich in organic matter and the larvae pass through four instars before pupation and adult emergence.

The eggs are elongated oval-shaped, pale at first and they become dark due to exposure to air with a solitary black “eye spot”. The larvae emerge through a J-shaped fissure and don’t have legs and white like with a dark head capsule. Those of the first instar can be characterized by the presence of two caudal bristles, all subsequent instars bearing four. Fourth instar larvae also have a prominent sclerite on the dorsum of the penultimate segment. The pupae are golden brown in colour and are affixed to the surface of the substrate in which they developed by the final larval exuvium. Just before emergence the wings and eyes become black. Male sand flies emerge about 24 h before females, allowing their external genitalia time to rotate 180 to the correct position for mating before females have emerged. The time from oviposition to adult emergence at ambient temperature is around 4-6 weeks. Some Palaearctic species diapause as larvae
 
Disease Transmitted Sandfly fever
 
Symptoms Fever, malaise, eye pain, and headache occurring mainly during the warm weather. Acute symptoms last for 2-4 days, but if the fever is severe it takes a week.
 
Type of Damage Phlebotomines feed on pools of blood by suck blood from a tiny wound they make in the skin of human.

Cutaneous leishmaniasis (oriental sore). At the site where a sandfly has bitten, an ulcer forms. At some instances a parasite is found in the area of a wound in some species, it also infects the lymphatic system, causing skin wounds along the lymphatic ducts.
 
Sources / Breeding Sandflies breed in safe places which are rich in organic matter e.g. cracks, rodent burrows, animal shelters and privies. They are nocturnal.

Sandflies mostly breed in salt mashes; nevertheless other species breed in fresh water areas and tree holes.Larvae of sandflies are found in mud, sand and debris around the ends of the ponds, creeks springs, lakes, in tree holes or in slimy covered bark. They swim freely in water and they are normally found in twigs and leave trash. The larvae pupate on floating debris. The adult female requires blood to mature the eggs. Males do not bite.
 
Prevention Insect repellent should be used on skin, so as to prevent the sandfly transmitted diseases. The use of mosquito netting sprayed with permethrin is recommended. Good sanitation and housekeeping prevents sandflies from lodging in the house.
Insecticide can be sprayed on outdoor breeding sites.
 
Control
  • Households are sprayed with residual insecticide on surfaces. This has been the most effective method used . This controltechnique is also used for killing
  • Destroy active qualities of reservoir species. Certain species of mammals can act as important reservoirs of Leishmania By depriving life to reservoir species which live near human households, disease rates can be decreased. One can make a use of rodenticide.
  • The area where the lava lives can be sprayed with an insecticide. In spite of its ineffectiveness.

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