Biology of the Blowfly

The Australian sheep blowfly, Lucilia cuprina, initiates over 90% of all flystrike in the Australian flock. Other fly species will strike sheep but only in small numbers and do not escalate into fly waves.

When conditions are right and susceptible sheep are present, relatively low densities of blowflies can cause extensive flystrike.

Ideal conditions for the blowfly involve warm, humid weather. They do not like;

• cool weather (less than 17°C)
• excessive heat (greater than 38°C)
• dry climates
• wind (greater than 30 km per hour)

Life cycle

Emergence of the blowfly after winter is controlled by temperature. The maggots over-winter in the ground as larvae or pre-pupae. As the soil temperature increases (>15°C) the larvae pupate and emerge.

The male is sexually mature at emergence. Females require a protein meal, from manure, carcasses, skin exudates (weeping skin) or existing flystrike before mating and seeking out, by smell, a place to lay their eggs. Lucilia can mature up to 300 eggs in each ovarian cycle and lay a new batch of eggs every 4–8 days.

The eggs hatch after 8–24 hours and the maggots immediately start feeding on the sheep, moulting twice during the 3–5 days before they drop off and burrow into the ground to pupate.

The normal blowfly life cycle in warm weather takes 2.5–3 weeks.

For further information on blowfly biology download the article below.

Sheep Blowfly Biology (25 KB)