Ectoparasites VI: Diptera

Question 1

What are general dipteran characteristics?

Answer 1

True flies (two-winged)
Complex metamorphosis

Question 2

What do larvae of some species of dipterans cause? What are adults of others?

Answer 2

Myiasis

Blood-suckers

Question 3

Describe the mouthparts of dipterans

Answer 3

They vary:

Lapping, piercing, combination, nonfunctional

Question 4

What are the 2 main groups of diptera?

Answer 4

Brachycera

Nematocera

Question 5

What are examples of Brachycera?

Answer 5

Myiasis flies (bot, blow, flesh, and muscid flies)
Stable flies
Horn flies
Keds (louse flies)
Horse and deer flies

Question 6

What are examples of Nematocera?

Answer 6

Mosquitoes
Biting midges
Black flies
Sand flies

Question 7

What is the parasitic stage for Brachycera?

Answer 7

Larval stage

Question 8

Where do most Brachycera breed?

Answer 8

In decaying material

Question 9

What are the mouthparts seen with Brachycera?

Answer 9

Lapping, piercing, nonfunctional

Question 10

What is myiasis?

Answer 10

Parasitism by fly larvae

Question 11

What are obligate parasites?

Answer 11

Those that require living tissues

Question 12

What are facultative parasites?

Answer 12

Those that go for necrotic tissue

Question 13

What are accidental parasites?

Answer 13

When an animal ingests something with maggots and they pass through, but they aren’t meant to be there

Question 14

Describe Oestridae (Bot flies)

Answer 14

Highly host and site specific
Adults non-parasitic
Aberrant hosts

Question 15

What is the type of myiasis associated with Oestridae subfamily Gasterophilinae?

Answer 15

Digestive

Question 16

What is the type of myiasis associated with Oestridae subfamily Oestrinae, Cuterebrinae?

Answer 16

Internal

Question 17

What is the type of myiasis associated with Oestridae subfamily Cuterebrinae, Hypodermatinae?

Answer 17

Cutaneous

Question 18

What are the Gasterophilinae species from most common to least common (horse bots)?

Answer 18

Gasterophilus intestinalis
Gasterophilus nasalis
Gasterophilus hemorrhoidali

Question 19

What is hatching of Gasterophilus eggs induced by?

Answer 19

Environmental cues

Question 20

Where are eggs laid with Gasterophils intestinalis?

Answer 20

Legs and shoulders

Question 21

Where does the L3 stage occur with Gasterophilus intestinalis?

Answer 21

Nonglandular portion of stomach

Question 22

Does Gasterophilus cause pathology?

Answer 22

Usually it causes very little pathology

Some association with stomach rupture, splenic abscesses, peritonitis

Question 23

How is Gasterophilus diagnosed?

Answer 23

Often postmortem, but sometimes we can find eggs

Question 24

What are the infestation signs of Oestrus ovis (sheep bots)?

Answer 24

Usually subclinical

Sometimes sneezing, nasal discharge, blockage

Question 25

Where is Oestrus ovis found?

Answer 25

In the nose of sheep

Question 26

What are the hosts of Cuterebra?

Answer 26

Rodents and squirrels are most common | Rabbits, dogs, cats

Question 27

Where do Cuterebra adults lay eggs?

Answer 27

In the host habitat

Question 28

How do Cuterebra larvae get into host?

Answer 28

They get onto the host fur and enter via natural openings, then migrate to subcutaneous location

Question 29

Where does Hypoderma (cattle bot) lay eggs?

Answer 29

On the host legs

Question 30

Where does L1 of Hypoderma occur?

Answer 30

Esophagus and spinal cord

Question 31

What happens with the other stages of Hypoderma?

Answer 31

They move to SubQ areas because part of their life cycle is exiting the host

Question 32

When does injury occur with Hypoderma?

Answer 32

When trying to escape flies

Question 33

Why is the timing of treatment of Hypoderma important?

Answer 33

You don’t want to treat L1 when they are in the esophagus or spinal cord because dead larvae release toxins which causes adverse reactions

Question 34

When do you want to treat Hypoderma?

Answer 34

Immediately after fly activity stops- NOT in winter

Question 35

Describe Calliphoridae blow flies

Answer 35

Adults have metallic color Lay eggs/larvae in tissue Most are facultative parasites, some obligate

Question 36

What are screwworms (Calliphoridae- Blow flies)?

Answer 36

Primary: Cochliomyia hominivorax (reportable) Secondary: Cochliomyia macellaria

Question 37

Where are Sarcophagidae (flesh flies) eggs laid?

Answer 37

Carrion, feces, wounds

Question 38

What can many Sarcophagidae cause?

Answer 38

Facultative myiasis

Question 39

Where do you usually find Muscidae larvae?

Answer 39

In decaying organic matter

Question 40

What is the pathogen transmission with Musca domestica (house fly)?

Answer 40

Mechanical (bacteria and viruses) | Biological (horse nematodes)

Question 41

What does Musca autumnalis (face fly) feed on?

Answer 41

Ocular/nasal discharge

Question 42

What is the pathogen transmission of Musca autumnalis?

Answer 42

Mechanical (bacteria) | Biological (nematode)

Question 43

What is cutaneous myiasis associated with?

Answer 43

Larval infestation from blow flies, flesh flies, and rarely muscid flies

Question 44

What are clinical signs of cutaneous myiasis?

Answer 44

Foul-smelling Depressed or restless Decreased weight gain

Question 45

Describe treatment of Cutaneous myiasis in small animals

Answer 45

Treat individual Clean wounds Remove maggots Avermectins

Question 46

Describe treatment of Cutaneous myiasis in large animals

Answer 46

Individuals are often not treated Dips/sprays Suffocation approaches

Question 47

What are muscid flies that are blood feeders as adults?

Answer 47

``` Stable flies (Stomoxys) Horn flies (Haematobia) ```

Question 48

Describe stable flies

Answer 48

Quick feeder | Breed in manure with feed

Question 49

Describe Horn flies

Answer 49

Slow feeder | Breed in manure only

Question 50

What are the common hosts of Stomoxys calcitrans?

Answer 50

Dairy cattle, dogs, horses, humans

Question 51

What is Stomoxys calcitrans the biological vector of?

Answer 51

Nematode (Habronema microstoma)

Question 52

What are common hosts of Haematobia irritans?

Answer 52

Beef cattle, horses

Question 53

What is Haematobia irritans the biological vector of?

Answer 53

Nematode (Stephanofilaria stilesi)

Question 54

What are the general control methods of Muscidae?

Answer 54

Sanitation Regular spraying of premises Fly baits, resin, strips, ear tags, UV traps Biological control

Question 55

Describe Hippoboscidae (Keds)

Answer 55

Many are not host specific Dorsoventrally flattened Piercing/sucking mouthparts Some stay on host whole life cycle, others don't Larvae stay in female's abdomen until ready to pupate

Question 56

Describe Melophagus ovinus (Hippoboscidae)

Answer 56

Transfer via direct contact Entire life cycle on host Trypanosoma melophagium

Question 57

Describe Lipoptena cervi (Hippoboscidae)

Answer 57

Wings break off once

Question 58

Describe Hippobosca equina

Answer 58

Wings throughout life

Question 59

Describe Tabanidae

Answer 59

Horseflies and deerflies Stout-bodied. vary in size Only adult females require bloodmeal

Question 60

What are the eggs of Tabanidae like?

Answer 60

Glued to vegetation overhanging water

Question 61

What is L3 of Tabanidae like?

Answer 61

Carnivorous

Question 62

What are adult Tabanidae like?

Answer 62

Strong fliers | Difficult to control

Question 63

Describe Tabanus spp. (horse flies)

Answer 63

Vary in size, but can be big Large eyes Livestock fighting off flies may not graze well

Question 64

Describe Chysops spp. (deer flies)

Answer 64

Smaller than Tabanus spp, but larger than house fly Banded wings Larvae feed on organic matter in soil

Question 65

What disease does Tabanidae transmit via mechanical transmission?

Answer 65

Anthrax (Bacillus anthracis) Anaplamosis (Anaplasma marginale) Tularemia (Francisella tularensis) EIA (Equine infectious anemia virus)