Head fly - Hydrotaea irritans

Question 1

What are the main hosts of concern for Hydrotaea flies (Head flies)?

Where are these flies mainly seen?

Answer 1

• Sheep, cattle, and horses
  
  • horned sheep most susceptible (Swaldales, Blackface)
• mainly northern europe

Question 2

What do the Hydroteae flies look like (Head fly)?

Answer 2

• olive-green abdomen
• orange-yellow coloration at the base of the wings
• mouthparts have a rasping device (prestomal teeth)
  
  • can’t puncture skin, but feeding increases the size of an existing wound
  • prevents wound healing

Question 3

How many generations are produced per year for Hydroteae flies (head flies)?

Generalize their life cycle.

Answer 3

• only one generation per year
• eggs are laid on decaying organic matter in the summer
• larvae emerge in the autumn, then go into diapause until the following spring
• pupation and continued development, then emergence of new generation of adults in the early summer

Question 4

What is the pathogenic significance of Hydroteae flies (head flies)?

Answer 4

• prevention//slowing of wound healing, or increasing the size of existing wounds
• irritation cause self-trauma
• have been implemented in summer mastitis - transmit T. pyogenes
• economic losses - stress due to “worry”

Question 5

What are some ways to control Hydroteae flies or the pathogenic concerns they cause?

Answer 5

• use of polled breeds
• application of cream at the base of horns
• impregnated ear tags or tail bands