acalypterae

• Order Diptera


  • Suborder Nematocera
  • Suborder Brachycera
  • Suborder Cyclorrhapha
• Suborder Cyclorrhapha


  • Section: Acalypterae
  • Section: Calypterae
• Family Gasterophilidae


  • Hairy flies
  • Mouthparts reduced and functionless
• Genera in Family Gasterophilidae


  • Gasterophilus
  • Cobboldia
• Gasterophilus


  • Larvae of several species are parasites of equines and are known as "bots" or "horse bots" - develop in the stomach of equines
  • Rarely found in dogs, pigs, birds and man
  • Adult: brown and hairy and are "bee-like"
• Gasterophilus intestinalis (aka. G. equi, "bots" in horses)


  • Most common species; 1-2 cm long, dark, robust, irregular flies with transverse band runs across either wing
  • Deposits eggs mainly around the fetlocks of the forelegs; larvae are laid chiefly in the mucosa of the tongue then down to the cardia of the stomach
  • Cause ulceration of the esophageal region of the stomach which is the most common lesion
  • Larvae: 2 rows of spines dorsally and ventrally to at least 10th segment. Spines blunt-tipped
• Gasterophilus nasalis - THROAT BOT FLY


  • Lay eggs on the hairs of the intermandibular region; larvae attach to the pylorus and duodenum
  • Larvae: 1 row of ventral spines on each segment: 3rd segment always with a row of dorsal spines
• Gasterophilus hemorrhoidalis - NOSE BOT FLY


  • Lay eggs on the hairs around the mouth and on the cheeks
  • Larvae chiefly in the mucosa of the tongue then down to the pharynx, to the stomach, then to the rectum, causing irritation then, inflammation of the rectum
  • Larvae: 2 incomplete rows of ventral spines on 3rd segment; Spines not interrupted medially on segment 11; spines are pointed
• Gasterophilus inermis


  • Larvae chiefly on the mucosa of the cheeks
  • Larva: 2 complete rows of ventral spines on 3rd segment; ventral spines interrupted medially on segment 11; Spines pointed
• Gasterophilus pecorum


  • Larvae on mucosa of the cheeks → pharynx → fundus of stomach
  • Larvae: 2 rows of ventral spines on segments; dorsal spines in complete rows only on seg 2 to 5; spines pointed
• Major species of Gasterophilus


  • G. intestinalis
  • G. nasalis
  • G. haemorrhoidalis
  • G. pecorum
• Minor species of Gasterophilus


  • G. inermis
  • G. nigricornis
• Life Cycle of Common Horse Bot Fly

  1. Eggs on hairs (7-10 days)

  2. Bots (larvae) inside horse 8 to 10 months from first frost to late spring

  3. Pupal stage on pasture 4 to 8 weeks in early summer

  4. Adult fly emerges mid to late summer

  5. Fly lives 7 to 10 days & lays up to 500 eggs
• The eggs are easily seen being 1-2 mm long and usually creamy white in color; they either hatch spontaneously in about five days or are stimulated to do so by warmth which may be generated during licking and self-grooming. Larvae either crawl into the mouth or are transferred to the tongue during licking.
• In the stomach the red larvae of G. intestinalis favor the cardiac region whereas the yellow G. nasalis larvae attach around the pylorus and sometimes the duodenum.
• Larvae remain and develop in this site for periods of 10-12 months and when mature in the following spring or early summer, they detach and are passed in the feces: in a few species, notably G. haemorrhoidalis, the larvae reattach in the rectum for a few days before being passed out.
• Pupation takes place on the ground and after 1-2 months the adult flies emerge. These do not feed and live for only a few days or weeks during which time they mate and lay eggs. There is therefore only one generation of flies per year in temperate areas.
• Pathogenic Significance


  • Adult flies are often a source of great annoyance when they approach horses to lay their eggs, especially those species which lay their eggs around the head
  • The presence of larva the buccal cavity may lead on to stomatitis with ulceration of the tongue. but this is very rare
  • On attachment by their or 2 hooks to the stomach lining, larvae provoke an inflammatory reaction with the formation of funnel-shaped ulcers surrounded by a rim of hyperplastic epithelium
  • These are commonly seen at postmortem examination of horses in carcas of high fly prevalence and although dramatic in appearance their true pathogenic significance remains obscure
  • Larvae of G. haemorrhoidalis can cause irritation when they reattach in the rectum
• Family Muscidae


  • Musca
  • Muscina
  • Morellia
  • Fannia
  • Stomoxys
  • Hydrotaea
  • Haematobia
• Family Muscidae


  • 2ND largest of the calypterate families with about 4000 species
  • Hypopleural bristles are ABSENT
  • Wings: Median Vein (M) is parallel to the Radial (R4 +5) wing vein or curving towards it; there is no definite elbow bend in the radial vein
• Musca domestica - "COMMON HOUSE FLY"


  • 5.8-6.5mm; ? 6.5-7.5mm in length
  • Tertiary strike-causing flies
  • Distributions: indoors and cosmopolitan
  • Thorax: yellowish-grey to dark grey with 4 longitudinal dark stripes which are equally wide and extends to the posterior border of the scutum
  • Abdomen: yellowish ground color with median black longitudinal stripe which becomes diffuse on the 4th segment
  • Eyes: reddish, HOLOPIC in males, DICOPTIC in females
  • Antennae: 3 segments; 3rd is biggest bearing an aristae which are bilaterally plumose to the tip
• Mouthparts of Musca domestica

  • Adapted for imbibing liquid food
  • Labium is expanded distally into 2 labella covered by pseudotracheae
  • "vomit drops" - saliva & crop fluid ejected to liquefy solid food before imbibing
  • "fly specks" - feces of flies deposited on food materials
• Life Cycle of Musca domestica

  1. Eggs (100-150/batch) -> larva, 12-24 hours

  2. L1-> L2, within 24 hours

  3. L2 -> L3, 3-6 days

  4. L3-> Pupa, 4-8 days

  5. Pupa -> Adult, 3-26 days
• COMPLETE LIFE CYCLE at about 8 days at 33-35 degrees Celsius
• ADULT FLIES may live for 15 to 25 days
• Suborder Cyclorrhapha


  Family Muscidae
• Squama


  Lobes or scale-like appendage at the junction of thorax and wings, well-developed, concealing the halteres
• Wings have veins which provide support and served as the path for air and blood circulation during the development of the wing before the fly emerge from the puparium
• The 4th longitudinal vein (M1+2) curves forward distally to nearly meet the vein R4+5 at the wing margin. R5 cell is nearly closed.
• Life cycle


  1. Eggs (100-150/batch) -> larva, 12-24 hours

  2. L1-> L2, within 24 hours

  3. L2 -> L3, 3-6 days

  4. L3-> Pupa, 4-8 days

  5. Pupa -> Adult, 3-26 days
• Housefly


  • Mechanical transmitters of: Viral infections (ex. Poliomyelitis), Bacterial infections (ex. Diarrhea and enteric fevers, typhoid, cholera, anthrax, tuberculosis and leprosy), Protozoa (ex. Entamoeba, Eimeria, Isospora), Helmiths eggs (Ex. Enterobius, Ascaris, Trichuris)
  • Intermediate host of equine stomach worm (Habronema spp.) and of chicken tapeworm (Raillietina spp.)
• Musca automnalis


  • COMMON NAME: Facefly of cattle
  • slightly larger than M. domestica
  • feeds on ocular and nasal discharges, eggs laid on fresh cattle feces and pupate in soil or in dry dung
• Musca crassirostris


  Able to fold back the labella and use the prestomal teeth to rasp the skin, draw blood which is the sucked up
• Species which follow the primary blood suckers (non-blood suckers but feed on sores and wounds)


  • Musca sorbens
  • Musca bezii
  • Musca lusoria
  • Musca vetustissima
  • Musca vetripennis
  • Musca pattoni
  • Musca fasciata
• Muscina stabulans


  • COMMON NAME: False stable fly
  • accidental cause of intestinal myiasis, common around stables, larvae found in rotting fruits and carrion
• Morellia spp.


  • COMMON NAME: SWEAT FLY SPECIES
  • Non-metallic
  • adults on flowers and vegetation but are attracted to sweat and mucus of man, cattle and horses
• Fannia canicularis


  • COMMON NAME: Lesser housefly
  • 4-6 mm length
  • greyish to almost black
  • aristae are bare and has 3 longitudinal stripes on dorsal thorax
• Fannia scalaris


  -COMMON NAME:Latrine fly or little housefly

  - resembles F. cannicularis but fleshy processes in larvae are more feathered
• Stomoxys calcitrans


  Stable fly, about as large as Musca domestica (7-8 mm), cosmopolitan distribution, outdoor fly, thorax grey with 4 longitudinal dark stripes, abdomen shorter and broader than housefly with 3 dark spots on each end of the 2nd and 3rd abdominal segments
• Stomoxys calcitrans


  • Piercing sucking mouthparts, proboscis prominent, directed horizontally forwards with small labella with teeth