DurgicalDurgical
EN
Open the app

Microbiology · Arthropod vectors

Lutzomyia !

  • Parasite
  • Exam priority: medium

A tiny hairy fly that bites at nightfall. It spreads leishmaniasis and Carrión disease and breeds in damp soil.

Updated 2026-11-01

Also called: sand fly, phlebotomine

At a glance

Shape
Body and wings covered in hairs; at rest the wings are held up in a V
Family
Psychodidae, subfamily Phlebotominae
Type
Blood-feeding dipteran insect (vector), New World phlebotomine
Size
Very small, 2 to 3 millimetres: it passes through many ordinary bed nets

Morphology

  • Yellowish hairy adult with long legs and pointed wings raised in a V.
  • Short hopping flight close to the ground.
  • Terrestrial, not aquatic, larvae that live in damp organic matter.

Transmission

  • The female takes up Leishmania amastigotes when biting; in her gut they become promastigotes that move to the proboscis.
  • At the next bite she injects promastigotes into the skin.
  • It transmits Bartonella bacilliformis (Carrión disease) in Andean valleys.

Reservoir: Wild mammals (sloths, opossums, rodents) for cutaneous leishmaniasis; Dogs for visceral leishmaniasis; Humans for Bartonella bacilliformis

Vector: Cutaneous leishmaniasis in Colombia: forest species such as Lu. trapidoi, Lu. gomezi and Lu. panamensis; visceral: Lu. longipalpis; Carrión: Lu. verrucarum and related species. Some authors now use new genera (Nyssomyia, Psychodopygus, Pintomyia).

Isolation precautions

What the care team adds to standard precautions.

  • Standard

Life cycle

  1. The female lays dozens of eggs in damp, dark places rich in organic matter (cracks, leaf litter, roots).
  2. Larvae live in the soil and feed on organic debris; they need no open water.
  3. After four larval stages they pupate, attached to the substrate.
  4. Egg to adult takes several weeks.
  5. The adult rests by day in dark places and bites at dusk and at night.

Virulence factors

  • Its saliva contains substances that dilate vessels and modulate skin immunity, which favours Leishmania infection.
  • Many species live in forest: they bite people who enter it (soldiers, farmers, miners).

Diseases it causes

  • Cutaneous, mucosal and visceral leishmaniasis Leishmaniasis →
  • Carrión disease (Oroya fever and verruga peruana) from Bartonella bacilliformis

Diagnosis

  • Capture with CDC or Shannon light traps and human landing catches.
  • Identification by the morphology of the genitalia and spermatheca (needs mounting) and by molecular methods.
  • Detection of Leishmania in captured females by dissection or PCR.

Treatment

Does not apply to the insect. It is controlled with pyrethroid insecticides on fine-mesh nets and walls, although scattered forest breeding sites limit control.

Drug class only; doses and regimens are set by the clinician from the current guideline.

Prevention

  • Fine-mesh insecticide-treated nets (e.g. deltamethrin).
  • Repellent, long sleeves and avoiding the forest at dusk and at night.
  • Indoor spraying in household foci and clearing leaf litter and organic matter near the house.

Test yourself

Think of the answer, then tap the question to see it.

Why does removing standing water not control Lutzomyia?

Because its larvae are terrestrial and live in damp soil with organic matter, not in water.

Which bacterium does Lutzomyia transmit and which disease does it cause?

Bartonella bacilliformis, the agent of Carrión disease: Oroya fever (acute phase with anaemia) and verruga peruana.

Which Leishmania form does the sand fly inject when it bites?

The promastigote, which macrophages engulf in the skin and which turns into an amastigote.

Why are fine-mesh nets recommended against sand flies?

Because they measure only 2 to 3 millimetres and pass through the mesh of many ordinary nets.

Add to my cards (4)

← Back to the group: Arthropod vectors

Educational content on microorganisms; not a treatment guide and no substitute for a health professional's advice. No doses are given.

Sources: Leishmaniasis (WHO, 2023); CDC - DPDx - Leishmaniasis (CDC, 2024); Carrion's Disease: More Than a Sand Fly–Vectored Illness (PLoS Pathogens, 2016); Parasitosis humanas (Botero y Restrepo), 5.ª ed. (Corporación para Investigaciones Biológicas (CIB), 2012).

Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake

Representative model, for educational purposes only.