Diptera:Cyclorrhapha

Question 1

Name the 4 families of Cyclorrhapha

Answer 1

Calliphoridae
Hippoboscidae
Oestridae
Muscidae

Question 2

The family Muscidae has 5 important genera to veterinary medicine. Name them and their common names

Answer 2

Musca- house flies
Stomoxys-stable flies
Hydrotaea-head flies
Haematobia-horn fly
Glossina- tsetse flies

Question 3

Name 4 species that belong to the genus Musca

Answer 3

M.domestica
M.automnalis
M.sorbens
M.vetustissima

Question 4

What are the morphological features of houseflies

Answer 4

-Non-metallic,Grey, black or brown flies
- they have 4 distinct longitudinal dark stripes on their thorax
- There is a sharp upward bend in the 4th longitudinal wing vein
-reddish eyes,sponging mouthparts
- legs are clawed with sticky hair on padlike structures

Question 5

Describe the lifecyle of M.sorbens

Answer 5

Females lay batches of creamy white, banana shaped eggs in organic rotting material. The eggs hatch in 12-24 hrs. The cylindrical segmented maggots have 3 larval instars and feed on decaying organic material. Larvae mature in 3-7 days and move to drier areas to pupate. Adult emerges 3-26 days later.

Question 6

Give the economic importance of the genus Musca

Answer 6

M.domestica causes annoyance to animals and man and are vectors of bacterial helminth and protozoal diseases.
M.automnalis transmits moraxell bovis(pink eye), Parafilaria bovicola and eyeworm Thelazia.

Question 7

Name two species of the head flies

Answer 7

H.irritans
H.albipuncta

Question 8

How are head flies morphologically different from Musca

Answer 8

Hydrotaea flies have an olive-green abdomen with orange-yellow discolouration at the base of the wings.

Question 9

What is the economic importance of Hydrotaea irritans and what are the control methods

Answer 9

Feeds on wounds of sheep and cause secondary bacterial infections.
In cattle they transmit bacterial mastitis

Control is by applying repellents to animals and using insect impregnated ear tags or tail bands in cattle to prevent mastitis.

Question 10

Name one species that transmits bacterial mastitis and pink eye in cattle

Answer 10

H.irritans
H.albipuncta

Question 11

What are the 3 species of stable flies

Answer 11

Stomoxys calcitrans
Stomoxys niger
Stomoxys sitiens

Question 12

What are the morphological features of species of Stomoxys

Answer 12

-grey in colour.
-thorax has 4 longing dark stripes
-Abdomen has 3 dark spots on the second and third abdominal segments.
-The proboscis is conspicuous and forward projecting
-palps are larger and shorter and the mouthparts are adapted for piercing and sucking.

The larvae of stomoxys have posterior spiracles which are well separated, each having three S-shaped slits.

Question 13

What is the pathogenic significance of Stomoxys

Answer 13

Transmission of Trypanosoma and Habronema
Painful bites

Question 14

Describe the life cycle of stable flies

Answer 14

Both sexes feed on blood. The female lays batches of 30 eggs in manure or moist decaying vegetable matter like hat contaminated with urine.eggs hatch in 1-4 days and larvae develop in 6-30 days. Pupation takes 6-9 days. The complete cycle may take 12-60 days depending on temperature.

Question 15

Name 2 species of Haematobia

Answer 15

H.irritans(Lyperosia irritans)
H.minuta

Question 16

Describe the features of an adult Haematobia irritans and the larval stage appearance

Answer 16

Adult
They stay on the host only leaving to lay eggs.
Grey colour with several dark stripes on the thorax
Proboscis held forward and unlike stomoxys
Palps are short and dark grey.

Larvae
Cylindrical and yellow-white with two D-shaped posterior spiracles.

Question 17

Why are Haematobia irritans pathogenically significant

Answer 17

Because they transmit Stephanofilaria(skin filaroid) in cattle

Question 18

Name the order, suborder, family and genus of tsetse flies

Answer 18

O-Diptera
SubO-Nematocera
Family- Glossinidae
Genus-Glossina

Question 19

The genus Glossina has 3 sub groups. Name these sub groups

Answer 19

G.palpalis -riverine species
G.fusca-rainforest species.
G.morsitans-savannah species.

Question 20

Name 4 species belonging to G.morsitans

Answer 20

G.austeni
G.morsitans
G.longipalpis
G.pallidipes

Question 21

Name 4 species belonging to G.palpalis

Answer 21

G.fuscipes
G.palpalis
G.tachinoides
G.pallicera

Question 22

Name 3 species belonging to G.fusca

Answer 22

G.brevipalpis
G.fusca
G.tabaniformis
G.longipennis

Question 23

Describe the general morphology of glossina

Answer 23

-Adults are narrow-bodied
-Colour yellow to dark-brown
-Thorax is dull, greenish-brown with inconspicuous stripes and spots
-Brown abdomen with 6 segments
-Wings at rest are held scissorlike over the abdomen at rest
-Hatchet-shaped medial cell
-Long forward projecting proboscis adapted for piercing and sucking.

Question 24

Morphologically differentiate the three subgenera

Answer 24

a)Fusca males have free superior claspers without a membrane btwn them; Fusca females 5 genital plates
b) Morsitans males superior claspers are completely joined by a membrane. The females have no genital plates
c) Palpalis males have superior claspers are connected by a thin membrane deeply divided medially. Female genital plates are 6.

Question 25

What is the pathogenic significance of Tsetse flies

Answer 25

They transmit trypanosomiasis. (Nagana in cattle and sleeping sickness in man)

Question 26

Describe the lifecycle of glossina

Answer 26

Females are viviparous and lay one larvae at a time, upto 8-12 larvae
The larvae are creamy white, segmented and posteriorly they have a pair of dark prominent ear-shaped protuberances ka polypneustic lobes with a respiratory function.
When mature the larva are deposited on the ground in bare sandy soil under a shade. Larvae wriggle into the loose sand to pupate for 4-5 wks.
Females emerging need to feed for 16-20 days before laying eggs.

Question 27

Explain methods of control for tsetse flies

Answer 27

Pesticide campaigns DDT and organic pesticides
Fly traps electric blue cloth.
Release of irradiated males
Using parasite refractory strains