Haematobia irritans (1)

Question 1

What are the hosts?

Answer 1

Cattle

Question 2

Describe adults

Answer 2

3-4 mm

Smallest blood sucking muscids

 - Half size/shorter proboscis from Stomoxys calcitrans
 - Piercing proboscis

Question 3

Explain life cycle

Answer 3

Overwinter (diapause)

Egg laid in freshly passed feces

Remain on hosts, leaving only to fly to another host

Length of life cycle: 7 days - several months

Question 4

What are the sites of infection?

Answer 4

Back

Sides

Abdomen of cattle

Around the horns/poll after feeding

On belly when raining

Question 5

Describe Pathogenesis

Answer 5

More than 200 flies leads to economic losses, bites hurt

May feed in thousands along back, sides, and ventral abdomen of cattle

Common name derived from clustering at horns when not feeding

Large numbers

 - Intense irritation 
 - Impair milk production
 - Weight gain

Transmit cattle helminths

Question 6

How do you diagnose?

Answer 6

Fly identification

Question 7

How do you treat and prevent?

Answer 7

Control - relatively easy

 - Flies spend much time on hosts
        - Parasiticides can be applied directly to cattle 
                - Sprays
                - Dusts
                - Back rubbers
                - Ear tags

Developed resistance to many insecticides

Insect growth regulators/Organophosphates fed to cattle, render manure unfit for development and pupation
- Breaks life cycle

MCLs effective

Question 8

What is the common name?

Answer 8

Horn fly