Family Oestridae..Genus Hypoderma (Warble Flies)

These are hairy flies.

Adult flies having primitive and non-functional mouth parts.

Adult life span is short.

Larva having functional mouth parts and long life span

There are 3 important generas;

• Hypoderma
• Oestrus
• Gaterophilus

Genus Hypoderma

• Also called warble flies
• Cause great economic losses
• Affect cattle, buffalo, sheep, goat, equines and sometimes human beings.
• These flies are present mainly in lower Punjab areas.
• Species include;
• H. Bovis
• H. Liniatum

Morphology

• These flies resemble honey bees.
• Have one pair of wings, Yellow orange abdomen having yellow orange hair with a broad band of black hair in middle.
• Larva size is 2.5-3cm and color is dirty white when emerges but becomes dark brown later on.
• Larva is barrel shaped and segmented body. Each segment bears spines.
• Larva is tapering interiorly and color of pupa is black.

Life cycle

• Adult flies are active during warm month of the year and lay eggs.
• Egg attaches to the lower region of the leg having hairs. H.Bovis has single eggs but H.Liniatum eggs are in a row of 6. Eggs of H.Bovis are above hock region and that of H.Liniatum are below hock region.
• Egg hatch and larva develop (L1). Size of L1 larva is 1mm. L1 crawl down the Hair, Penetrate Hair follicles and reaches the Diaphragm region. This migration is aided by paired mouth hooks and secretion of proteolytic enzymes.
• From the diaphragm, L1 move toward resting site during autumn. Resting site of H.Bovis is epidural fat of spinal canal and that of H.Liniatum is sub mucosa of esophagus.
• They spend winter over there.
• With the onset of spring season, L1 mould to L2 and become active and move toward skin of back.
• With the onset of summer season, L2 mould to L3. L3 can be seen under the skin. These come out of the skin and fall on the ground. They move in the soil for some time.
• From the larva, pupa and from the pupa, adult emerges.
• Adult copulate, female lay eggs and then die within 1-2 weeks.

Pathogenic Effects

• Creates disturbance and cause restlessness for the animals and human beings due to buzzing noise
• Greenish yellow gelatinous mass is formed on the damaged skin of back and it is called as Butcher Jelly.
• Due to buzzing noise, meat production is reduced and also milk production.

Treatment & Control

• Ivermectin…. Ivotec, Ivomec (1ml/50kg B.W subcutaneously)
• Use insecticides;
• Organo Chlorine…… DDT, hexachlorocyclohexane/ benzene hexachloride
• Organic phosphate…. Trichlorofen, neguvan, cumafex, neocidal, diazinon and asuntal
• Synthetic pyrethroid...Cypermethrine and Ecoflee
• Carbamates…
• To treat toxicity, Atropine sulphate is used.