Tabanidae

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.

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

• Mechanical vectors for many diseases
  • Bacteria such as anthrax and pasteurellosis
  • Viruses such as Equine infectious anaemia and African horse sickness
  • Rickettsiales, such as anaplasmosis

• Intermediate hosts for some trypanosome diseases