Biting Flies 1

Biting Flies 1

1. Stomoxys

   • Stable Fly
   • Life Cycle
     • Spends most of ti's time off the host! Just settles on it's host to feed but spends most of it's time on buildings, foliage & fences.  Attacks humans & animals WORLDWIDE
     • Eggs laid on rotting straw!
     • Completed in a month & then the adult only lives a month.
   • How's it recognised?
     • Looks like a house fly
       • KEY DIFFERENCE: Forward pointing proboscis shows that it's a biting fly
     • Thorax = grey with darker grey stripes
     • Abdomen = grey with black spots
   • Pathogenic significance?
     • Production losses
       • Painful bite
       • Can account for a 20% decrease in milk yield & weight gain!
     • Disease transmission
       •  - Pathogenic bacteria + viruses (mechanical transmission)  - Protozoa e.g. trypanosomes (mechanical transmission)  - Helminths (intermediate host for Habronema)
   • Control as you would a musca

2. Haematobia

   • Resident fly that spends most of it's time ON the host. 
   • Horn Fly
     • Mostly in South England! Also Europe, USA & Australia
   • Feed on places where the skin's thin!
     • This can include the belly, dewlap & udder.  It just rests along the back, shoulders & sides. 
   • Looks like a stable fly but smaller!
   • The flies tend to face downwards when resting!
   • Life Cycle
     • Eggs laid in fresh cow poo!
       • Larvae pupate in soil beneath dungpat
         • Adult emerges within a week
   • Pathogenic significance
     • Production Losses
       • Cluster around head annoying the sheep
       • Bites - skin wounds - attract other muscid flies & blowflies
     • Disease Transmission
       • Pathogenic bacteria + viruses (mechanical transmission). Helminths (intermediate host for Stephanofilaria). 
   • Why are horn flies easier to control than other musca species?
     • They are in contact with the host more!
       • Why is this also a disadvantage in terms of control?
         • They develop insecticidal resistance more rapidly! As the concentration decreases over time the flies aren't killed immediately! 

3. Read the notes on the boxes!

4. Haematobia irritans = resident fly & stomoxys = just a visiting fly

5. Hippoboscidae

   • Hippobosca spp.
     • Loves horses & cows Old world (
     • Forest Fly
       • Most important species in UK = H. equina
     • How is it recognised?
       • It's bigger than the house fly!
       • Medium sized fly
         • 1cm 
       • Reddish-brown with yellow spots on thorax & abdomen
       • Reduced wings & the veins are crowded towards the anterior margin (the front of the wing)
         • They can't fly very well.
           • Just jump from animal to animal.
         • Biting mouthparts! The proboscis is retracted in the head except during feeding.
     • Life Cycle
       • Adult flies are about from May - October
       • Mate on the host & the female deposits a SINGLE LARVAE in the soil / damp humus
         • There's still an egg except it ruptures in the uterus & releases a larvae. 
       • The larvae pupate & adult flies emerge the following spring
       • 1 YEAR
     • Pathogenic significance
       • Biting irritation & annoyance
         • Large numbers are found on the perineum & inner thigh where there's thin skin. 
       • Mechanical vectors of non pathogenic Trypanosoma theileri in cattle
         • Another type in sheep Don't panic it's normal!
     • Control
       • Topical insecticide application (including repellant & residual action)
   • Melophagus ovinus
     • Sheep ked
       • Sheep & goats Deer have a different species
     • How is it recognised?
       • Medium sized hairy fly
         • 6mm long
       • Biting mouthparts
         • Forward pointing proboscis mounted on a short head.
       • Wingless
       • Strong legs & claws
     • Life Cycle
       • All ON THE HOST
         • Although adult hosts may survive for one week off the hosts
       • Female keds lay single larvae on the fleece which pupate.
         • Adult ked lay single larvae on the fleece which pupate.
           • The adult merges after a few weeks - months
             • Temperature dependant
     • Pathogenic Significance
       • Most numerous when the fleece is long in autumn / winter
       • Transmission = good because they're found on surface layers of the fleece
         • Long wooled breeds = most susceptible. 
       • Anaemia if there'slots (suck blood)
       • Wool damage
         • Irritation
           • Scratchy & results in self inflicted damage
         • Staining by ked fleeces
       • Intermediate host
         • For non pathogenic Trypanosoma melophagium in sheep.
     • Control
       • Sheep dipping & spraying controls keds.  Shearing reduces ked numbers. 

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