Introduction

Also known as: Horse flies

Tabanidae flies are found throughout the world and although commonly being known as the horse fly they attack a wide variety of animals including humans. There are several species of veterinary importance;

  • Tabanus
  • Chrysops - also known as deerflies
  • Haematopota - also known as clegs


Recognition

Adults

Tabanidae flies are large flies, up to 2.5cm long with bodies that are usually dark in colour. The dark bodies may have stripes or patches of colour down them or be entirely coloured in some cases. They have broad heads with biting mouth parts and bulging eyes that are often brightly coloured. The mouthparts are adapted to biting a sucking blood, and always point downwards. They consist of paired mandibles and maxillae which are used for cutting and rasping to create a feeding hole. Blood is then sucked using a protruding hypopharynx. The mouthparts are short and deal roughly with the host, this is often the cause of pain for the host. Only females take a blood meal, males lack mandibles and may only feed on honeydew and nectar.

The winds of Tabanidae flies have a distinctive venation

Larvae
Eggs
  • Specific wing venation
    • Closed discal cell shape


Life Cycle

  • Eggs laid on leaves overhanging water
  • Larvae drop into water
  • 1 year later larvae emerge onto dry land to pupate
  • Adult flies emerge a few weeks after pupating
  • Life cycle takes over 1 year to complete


Pathogenesis

  • Most active on hot, sunny days
  • Locate prey by sight
  • Cause painful irritating bites
  • Intermediate hosts for some trypanosome diseases