Diptera - Culicoides, Simulium, Gasterophilus and control

Question 1

What are the biting midges? How big are they?

Answer 1

Culicoides spp

Question 2

What are the distinguishing features of culicoides?

Answer 2

Tiny (1-4mm)
Brown/black body
Mottled wings

Question 3

How do culicoides feed?

Answer 3

Dig holes and feed on free blood

Question 4

Where do culicoides lay eggs?

Answer 4

Damp areas (marsh land, compost)

Question 5

How long is the egg to adult life cycle of culicoides?

Answer 5

3 weeks

Question 6

How many generations of culicoides are there per year?

Answer 6

1-2

But in huge numbers

Question 7

What do culicoides cause?

Answer 7

Sweet itch (allergic response to them)
Irritation, allergic dermatitis
Self-inflifcted rubbing lesions on withers, mane, tail

Question 8

What disease are midges vectors of?

Answer 8

Equine arboviruses:
African horse sickness
Blue tongue
Schmallenberg

Question 9

What is the species of black flies?

Answer 9

Simulium spp

Question 10

What are the distinguishing features of simulium spp flies?

Answer 10

Small (1-4mm)
Brownish/orange stout body
Humped thorax
Clear wings

Question 11

Where do simulium spp lay their eggs?

Answer 11

Require running water

Rivers, streams

Question 12

How long does it take for a generation of simulium to form?

Answer 12

4 weeks

Question 13

What do simulium spp cause in ducks and geese?

Answer 13

Leucocytozoon (arctic regions)

Question 14

What is the species of the horse bot fly, in the Oestridae family?

Answer 14

Gasterophilus spp

Question 15

What type of parasites are Gasterophilus spp? When are they active/

Answer 15

Obligate myiasis parasite

Question 16

What are the 3 species of Gasterophilus?

Answer 16

G. intestinalis
G. nasalis (around teeth/nasal cavity)
G. haemorrhoidalis (retum)

Question 17

What are the distinguishing features of Gasterophilus flies and eggs?

Answer 17

Long triangular shaped abdomen

Large barrel shaped eggs with double row of spines

Question 18

How many generations of Gasterophilus intestinalis are there each year? When are the eggs laid and where?

Answer 18

1 generation

Eggs laid in Summer on inner legs, hock and shoulders

Question 19

Describe the life cycle of G.intestanlis

Answer 19

Burrow in tongue
Moult and exit to pharynx
Moult to L2 and cluster in stomach 
Moult to L3 and remain to dune 
L3 passed into dung in June

Question 20

Do Gasterophilus spp have clinical significance?

Answer 20

Surprisingly little - large red larvae in faeces cause alarm to owner s

Question 21

How is Gasterophilus diagnosed?

Answer 21

Larve in faeces in Spring

Eggs on tips of hairs in Summer

Question 22

How can Gasterophilus be controlled?

Answer 22

Removal of eggs on tips of hairs

MLs - ivermectin, moxidectin

Question 23

What type of management is used for fly control?

Answer 23

Integrated pest management - treat accommodation, fly insecticides, habitat and husbandry, barrier methods (stripes!)

Question 24

What is the main group used as fly insectidcides?

Answer 24

Synthetic pyrethroids (ear tags, spray on, pour on)
Essential oils gain popularity

Question 25

Dung removal in barns can be used to control which species of fly?

Answer 25

Musca domestica

Stomoxys calcitrans

Question 26

How can Culicoides midges be reduced? (What can be removed)

Answer 26

Compost heap