Gad flies (Tabanidae)

Question 1

What are some general characteristics of Gad flies (Tabanidae)?

Where are they distributed?

Answer 1

• medium to large flies (2.5 cm long, with 6.5cm wingspan)
• mouthparts are short, strong and downward pointing
• found on every continent (except Antarctica)

Question 2

How long does their life cycle take?

Where do the females lay their eggs?

Answer 2

• total life cycle can take 4-5 months
  
  • larvae may hibernate for up to 3 years
• females lay their eggs on the underside of vegetation or stones, in muddy or marshy areas
  
  • larvae drop off into water//mud and feed on decaying organic matter or small arthropods
  • emergence in spring and summer (or start of the rainy season)

Question 3

What is the pathogenesis of Gad flies (Tabanidae)?

Answer 3

• females are intense blood-feeders, and can cause the loss of up to 200ml of blood a day from the host
• deep painful bites ==> stress and ‘worry’
• transmit:
  
  • bacteria - anthrax, Anaplasmosis, Pasteurella
  • Viruses
  • Parasites - T. evansi (Surra - camels, horses)

Question 4

Why is control hard?

Answer 4

• breeding places are diffuse and difficult to detect
• can use insecticides on animals houses and on the animals themselves