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

Tabanidae flies are large flies, up to 2.5cm long with bodies that are usually dark in colour. 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, 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 the female flies take a blood meal,

• Biting mouthparts
  • Short, strong and down pointing proboscis
  • Only females suck blood

• Dark colour with stripes or patches of colour on body and wings

• Large eyes
  • Often brightly coloured

• Specific wing venation
  • Closed discal cell shape

• Stout

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