VPA 221: Veterinary Entomology and Acarology (1+1)

House Fly and Stable Fly- Characters

DIFFERENCE BETWEEN HOUSE FLY AND STABLE FLYT

Characters	House Fly (Musca domestica)	Stable Fly (Stomoxys calcitrans)
MORPHOLOGY
Common Name	House Fly, Picnic Fly, Dairy Fly (View image...)	Stable Fly, Dog Fly, Biting house Fly (View image...)
	Medium sized, grey in colour, 6 to 7 mm long	Resembles M.domestica
Head	Two large compound eyes Three segmented antenna Presence of arista on the third antennal segment Arista bilaterally plumed upto the tip Mouthparts- lapping and sponging type of mouth part. (Click here to view the mouth parts of Musca) Retractible into the head Flies are not blood suckers	Differs in that the arista is plumed only on the dorsal aspect- has 8-10 bristles Mouthparts non retractile and a forwardly directed baton like proboscis. (Click here to view the mouth parts of Stomoxys) Biting type of mouth part Flies are blood suckers
Thorax	Grey with four longitudinal dark stripes all of which extend to the posterior border of the thorax Wing venation is characteristic in that the 4th longitudinal vein curves upwards at about the middle and joins the 3rd vein to form the closed apical cell	Grey with four longitudinal stripes but the lateral pair are narrow and do not extend upto the posterior border The apical cell is open Wing kept at divergent angle
Abdomen	Yellowish round colour Five segments of which 4 are visible. Presence of median black longitudinal stripe which diffuses on the 4th abdominal segment in male while in females either side of the abdomen is marked with a diffuse dark band	Ground grey Yellowish stripes on 2ndand 3rd segment which do not reach the lower border Two lateral circular dots on 2nd and 3rd segment.4th segment wth triangular spot or band
LIFE CYCLE
Breeding areas	Garbage, manure- horse dung preferred, decaying organic debris (View image...), Poultry manure, human excreta, abundant in rainy season	Prefers to lay eggs on the bedding material of horses- that is straw which is soiled with urine of the horses Never breed on human excreta, abundant in summer and autumn
Eggs	100-150 eggs are laid at a time and an average of 600/lifetime Elongate creamy white, oval/banana shaped/ 1mm long with two ridge like thickenings on the dorsal aspect- the hatching pleat Singly laid	25- 50 eggs are laid after blood meal Eggs are dirty white or yellow in colour, 1 mm, with only one dorsal ridge or hatching pleat Both male and female suck blood
Larvae	Three larval stages. Larval development takes a week L3 12 mm long, white, maggot like with 12 segments, 3 thoracic and 8 abdominal segments (View image...) Head with two chitinised black oral hooks with sensory tubercles (2) Mouth lies between them Above mouth is a pair of hooks- black and chitinous Oral (or) mouth hooks- Its part of cephalopharyngeal skeleton. Left hook smaller than right Last segment largest with obliquely truncated shape Ventral aspect of the segments (8) show cresentric pads covered with short recurved spines-aids in locomotion Fan shaped lateral spiracles on Prothorax D shaped with 3 ‘m’ shaped winding slits-button- posterior spiracles	Acephalus, apodous. The larval stages last 20 days Similar to Musca spp. except that the posterior spiracles are widely separated and are roughly triangular in shape with three ‘S’ shaped stigma slits
Pupa	Last larval skin retained- puparium Barrel shaped,6-8 mm long, creamythen turn reddish (View image...) Coarctate , brown, oval shaped Pupa emerges out by inflating the ptilineal suture This stage lasts for 3 days	Pupation in drier part of breeding area Similar to Musca spp. Pupal stage lasts for 8 days
Adult	Sexually mature in 10-14 days after imergence Average life span- 1 month Musca adult flies do not feed on blood – they lap blood which flow out of wounds etc Entire lifecycle is completed in 7 to 12 days	Life span- 1 month Entire lifecycle is completed in one month Both male and female Stomoxys spp. are haematophagus
EFFECT ON THE HOST
Direct effect	Nuisance, fly worry is known to bring down production and feed conversion efficacy Feed on wounds etc and result in production of myiasis	Both male and female suck blood and are painful biters Anaemia in young animals Fly worry
Indirect effect- vector potentiality	Musca is a synanthrope and hence has a high vector potentiality Bacterial diseases such as cholera, typhoid, paratyphoid, T.B, salmonella, E.coli dysentery, anthrax etc., Viral diseases such as poliomyelitis and infectious hepatitis Protozoan diseases such as amoebic dysentery, giardiasis Acts as the intermediate host for Habronema muscae, Draschia megastoma, Thelazia rhodesii, Raillietina spp., Choanotaenia infundibulum  Mechanical transmission of the eggs of the following is also possibleTaenia solium, Toxocara sp, Ancylostoma, Hymenolepis, Dipylidium caninum and Diphyllobothrium latum	Mechanically transmits Trypanosoma evansi Also is a mechanical vector for anthrax, rinderpest, tetanus bacteria and poliomyelitis virus Its an intermediate host for Habronema majus