Ectoparasites: Flies of Veterinary Importance

M.7, W.4, L.3

List the general morphology of dipteran flies

1. Single pair of antennae

2. One pair of wings

3. 3 pairs of legs

4. Modified hind wings (halteres)

5. Body:

A. Head

B. Thorax

C. Abdomen

List some concerns when it comes to dipteran flies

1. Fly worry

• economic losses

2. Disease transmission

• mechanical, biological

3. Parasitic

which species are non-biting flies?

Musca & Phortica spp.

List three non-biting flies (scientific and regular name)

• Musca domestica (House Fly)

• Musca autumnalis (Face Fly)

• Hydrotaea irritans (Head Fly)

list the morphology of non-biting flies

• 5.5-7.5 mm long

• a pair of veined wings

• sticky hair pads at the end of legs

List physical characteristics of a house fly (Musca domestica) that help distinguish it from other non-biting flies

• 4 longitudinal black lines on thorax

• pointed abdomen

• dark color

List physical characteristics of a face fly (Musca autumnalis) that help distinguish it from other non-biting flies

• rounded abdomen

• black thorax

What areas of the body do face flies (Musca autumnalis) gather?

gather in large numbers about the head, eyes, and muzzles of animals

List physical characteristics of a head fly (Hydrotaea irritans) that help distinguish it from other non-biting flies

• olive/brown color

• orange patches at base of wings

where do these 3 flies like to gather around?

• open wounds

• mucus membranes

• anything that’s smelly

List and describe how non-biting flies act as disease vectors

• Mouthparts

  • rasping device (prestomal teeth)

    • increases size of existing wounds and prevents wound healing

• Feet

  • Pulivilli - sticky pads on feet

  • Tarsal claws

How do Musca flies spread habronema spp (nematode)?

-horse expels eggs in feces

-fly lays eggs in feces

-larvae ingest eggs

-adult flies emerge

-new adult flies deposit eggs in horse mouth

-L3 to stomach- mature

-repeat

What is the main vector for thelaziasis?

Phortica variegata

Where does phortica variegata typically cause clinical symptoms?

Eye

What is the scientific name for biting midges?

Culicoides spp

Which sex of culicoides spread disease?

Female (they are the only blood feeders)

What species are impacted by sweet itch?

Horses and donkeys

What are the clinical symptoms of sweet itch?

Pruritic dermatitis- bald patches, skin damage

When is the season significance of sweet itch?

April to September

What causes sweet itch?

Culicoides

What parasite is commonly spread via culicoides?

Onchocerca cervicalis

What are common virus' spread by Culicoides?

Schmallenberg, blue tongue, African horse sickness

What are the clinical symptoms for adults cattle with Schmallenberg virus?

Inappetence, diarrhea, fever, decreased BCS, reduced milk

What clinical symptoms can happen with pregnancy if infected with Schmallenberg virus?

Congenital malformations and abortion

How can culicoides be controlled?

Midge eater machines, housing, repellents

What is the scientific name for sheep ked?

Melophagus ovis

What is the lifecycle of melophagus ovinus?

-live entire cycle on host

-females lay egg (1 q 11 days)

Where does melophagus ovinus typically bite?

Neck, breast, shoulder, flank, rump

What are the clinical symptoms of a small melophagus ovinus infection?

Intense pruritus

What are the clinical symptoms of a severe melophagus ovinus infection?

Loss of condition, anaemia

How can melophagus ovinus be controlled?

Shearing!!, insecticide

What insecticide can be used for melophagus ovinus?

Pyrethroids

What are the types of myiasis?

Obligate, facultative, accidental

What are potential clinical symptoms of myiasis?

Tissue damage, ulceration, loss of function, secondary infections, death

What is the scientific name for a warble/bot fly?

Hypoderma spp

What are the important species of Hypoderma spp?

Hypoderma bovis/lineatum

What is the lifecycle of Hypoderma spp? (Simplified)

-adult fly

-deposit egg on hair

-egg hatch (3-7d)

-L1 migrate to tissue (2-4mo)

-migrate to back tissue

-pierce skin to respiration

-L3 erupt

-pupate in soil

What is the significance of Hypoderma in relation to livestock?

Reduce grazing, reduce wt, stock panic, damage hide, reduce carcass value

What insecticides can be used to react Hypoderma?

Ivermectin and doramectin

What are the three fly types utilize facultative myiasis?

Lucilia, phormia, calliphora

What species of Hypoderma migrate to the spinal cord?

Bovis

What species of Hypoderma migrate to the esophagus?

Lineatum

What type of blow fly has a green body?

Lucilia sericata

What type of blowfly has a black body?

Phormia terranova

What type of blowfly has a blue body?

Calliphora spp

What is the lifecycle of blow flies? (Simplified)

-eggs on fleece (hatch 10-12 hrs)

-larvae (3-10 days)

-drop of ground, burrow, pupate

-adult flies emerge

*attracted to smelly/wet

What are the primary blow flies?

Lucilia, phormia

What does being a primary fly mean?

Can initiate strike

What are the secondary blow flies?

Calliphora

What does being a secondary fly mean?

Cannot initiate strike

What are the common body regions impacted by fly strike?

Body, breech, poll, penile sheath

What type of strike typically impacts fine wool breeds?

Body strike

What type of strike typically impacts wrinkly animals?

Body strike

What type of strike typically impacts narrow breech breeds?

Breech

How can blow fly strike be controlled? (5)

Prevent diarrhea, shearing, tail dock, treat lameness, control population

How do blowflies impact sheep productivity?

Increase time to market, reduce reproduction, downgrade wool, reduce leather quality

What fly is this?

Musca domestica

What fly is this?

Hydrotaea irritans

What fly is this?

Musca autumnalis

What fly is this?

Culicoides impunctatus (midge)

What fly is this?

Melophagus ovinus (sheep ked)

What fly is this?

Phortica variegata

What fly is this?

Hyoderma bovis/lineatum

What fly is this?

Lucilia sericata

What fly is this?

Phormia terranova

What fly is this?

Calliphora spp