Tabanus spp./Chrysops spp. (2)

Question 1

What are the common names?

Answer 1

Tabanus spp.

 - Horse Flies
 - Gad Flies

Chrysops spp.
- Deer Flies

Question 2

What are the hosts?

Answer 2

Any animal (generally large animals)

Humans

Question 3

Describe adults

Answer 3

Medium to large - up to 25 mm long
- Wingspans up to 65 mm

Horseflies larger - 10-50 mm

Horseflies highly colored

Deer flies medium sized

 - Dark band across wings
 - Antennae elongate
 - Bite horses in shaded areas (horses will stand in sun to avoid)

Mouthparts adapted for slashing and sponging

Question 4

Explain life cycle

Answer 4

Adult flies lay egg in muddy/marshy areas
- Underside of vegetation/on shores

Requires minimum of 4 months, can last up to 3 years

Question 5

What are the sites of infestation?

Answer 5

Anywhere on animal

Question 6

Describe the Pathogenesis

Answer 6

Only females feed

 - Inflict painful bites
 - Suck blood
 - Intense irritation/annoyance
 - Feed primarily on large animals (cattle and horses)
        - Become restless in fly presence

Mechanical vectors of organisms responsible for:

 - Anthrax
 - Pastuerellosis
 - Trypanosomosis
 - Anaplasmosis (gall sickness - disease in ruminants)
 - Equine infectious anemia
 - Human filarial disease (loasis)

Question 7

How do you diagnose?

Answer 7

Fly identification

Question 8

How do you treat and prevent?

Answer 8

Most difficult to control

Adulticide compounds used for other biting flies can kill both horse and deer flies

Flies intermittent feeders

 - May not be exposed to compounds
 - Larger doses may be required

Horse fly traps effective - confined to manageable areas

Pyrethroid pour ons - limited repellants

Self-application techniques - not effective

Breeding places - diffuse hard to detect
     - Remove unnecessary woody plants
     - Drain wet areas
     - Insecticides in water may not have detrimental environmental 
        effects

Question 9

What is important about Tabanus spp./Chrysops spp.?

Answer 9

It is ZOONOTIC