Equine flies (year 2)

Question 1

what do muscidae feed on?

Answer 1

secretions they can either be biting or non-biting

Question 2

what defines a myiasis fly?

Answer 2

one that lays eggs on an animal and then their larvae invades/feeds on living or necrotic tissue

Question 3

name the non-biting muscidae effecting horses

Answer 3

Hydrotaea irritans
Musca autumnalis
Musca domestica

Question 4

describe the morphology of Hydrotaea irritans

Answer 4

5mm
sponge-like mouthparts (proboscis)
orange wing base
green abdomen

Question 5

how many generations does Hydrotaea irritans have each year?

Answer 5

1 emergence in summer (July)

Question 6

describe the lifecycle of Hydrotaea irritans

Answer 6

deposit eggs on pasture soil, theses develop to L1, L2 and L3 they then pupate and emerge as a fly

Question 7

where is Hydrotaea irritans normally found?

Answer 7

it is exophillic and typically found on wooded pasture

Question 8

when is Hydrotaea irritans most active?

Answer 8

overcast, warm and humid days in late summer

Question 9

what is the hosts reaction to Hydrotaea irritans?

Answer 9

tail swishing and rapid head turn to dislodge flies

Question 10

where on the host is Hydrotaea irritans found?

Answer 10

teats and eyes

Question 11

where on the host is Musca autumnalis found?

Answer 11

eyes, muzzle and face

Question 12

describe the lifecyle of Musca autumnalis

Answer 12

exophilic fly that develop in dung on pasture

there are usually a number of generations each year that build up in late summer and autumn

Question 13

what diseases/parasites is Musca autumnalis a vector for?

Answer 13

infectious bovine keratoconjunctivitis

eye/stomach worms

Question 14

describe the morphology of Musca autumnalis

Answer 14

striped thorax

Question 15

where is Musca domestic found?

Answer 15

breeds and lives inside accommodation

Question 16

what is the main biting muscidae?

Answer 16

Stomoxys calcitrans

Question 17

where on the host does Stomoxys calcitrans feed?

Answer 17

legs and flanks

Question 18

where is the breeding site of Stomoxys calcitrans?

Answer 18

inside barns/accommodation on urine soaked straw and organic matter

Question 19

describe the lifecycle of Stomoxys calcitrans

Answer 19

eggs hatch - temperature dependant

L1, L2 and L3 form and then pupate then the fly hatches

Question 20

how long is the lifecycle of Stomoxys calcitrans in summer?

Answer 20

2-3 weeks

Question 21

where can adult Stomoxys calcitrans be found?

Answer 21

warm unexposed areas near building such as gate posts and machinery

Question 22

describe the morphology of Stomoxys calcitrans

Answer 22

8mm
long pointing proboscis flanked by small thin palps
large chestnut eyes

Question 23

what are the host responses to Stomoxys calcitrans?

Answer 23

stamping feet, gadding, shivering, rapid head turn, tail swishing

Question 24

what pathogens does Stomoxys calcitrans transmit?

Answer 24

equine infectious anaemia

Question 25

name the non-muscid biting flies

Answer 25

Cullicoides spp. Tabanidae Simulium

Question 26

what are the two genre of tabanidae and how are they identified?

Answer 26

tabanus - large clear wings | haematopota - mottled wings

Question 27

describe the morphology of tabanids

Answer 27

large irredescent eyes 10-25mm stubby mouthparts

Question 28

what is the breeding sites for tabanids?

Answer 28

wet pasture, marshy land

Question 29

what time of year do tabanids emerge?

Answer 29

July/August

Question 30

what are tabanids mechanical vectors of?

Answer 30

equine infectious anaemia trypanosomes bovine anaplasmosis

Question 31

what are Culicoides spp. know as?

Answer 31

biting midges

Question 32

describe the morphology of Culicoides spp.

Answer 32

1-4mm mottled wings brown/black body

Question 33

describe the lifecycle of Culicoides spp.

Answer 33

dig a hole in host and feed on free blood, eggs are laid in damp organic matter

Question 34

how long does the lifecycle of Culicoides spp. take and how many generations are there per year?

Answer 34

less than 3 weeks | one-two generations a year

Question 35

when are Culicoides spp. most active?

Answer 35

duck and dawn - crepuscular

Question 36

what can Culicoides spp. bites cause in the UK?

Answer 36

sweet itch - seasonal recurrent allergic dermatitis pruritis saliva hypersensitivity self inflected wounds

Question 37

what are Culicoides spp. a vector of?

Answer 37

arboviruses including African horse sickness, blue tongue and schmallenberg

Question 38

describe the morphology of Simulium spp.

Answer 38

2-5mm brown/black stout body humped thorax clear wings

Question 39

where is the breeding site for Simulium spp.?

Answer 39

vegetation in fast flowing streams and rivers

Question 40

name the myiasis fly of horses

Answer 40

Gasterophilus spp.

Question 41

what are the three species of Gasterophilus?

Answer 41

Gasterophilus intestinalis Gasterophilus nasalis Gasterophilus haemorrhoidalis

Question 42

describe the morphology of Gasterophilus spp.

Answer 42

20mm Adults are hairy, orange/black pointed abdomen bright red larvae

Question 43

describe the lifecycle of Gasterophilus intestinalis

Answer 43

eggs laid late summer on inner forelegs, hocks, shoulders larvae hatch and burrow into the tongue, moult to L2 and exit to the pharynx (takes 3-4 weeks) they then cluster in oesphageal (cardiac) portion of stomach where they feed and moult to L3 and remain there until the Spring passed in dung around June

Question 44

describe the lifecycle of Gasterophilus nasalis

Answer 44

eggs laid under jaw and burrow into space around teeth then they moult to L2 and move into the pyloric part of the stomach

Question 45

describe the lifecycle of Gasterophilus haemorrhoidalis

Answer 45

eggs laid on lips then migrate into the mouth, moult and then move to the stomach and duodenum they moult again and attach to the rectum

Question 46

describe the pathogenesis of Gasterophilus

Answer 46

not very pathogenic even though they cause large ulcers | worry for owners