Lesser house fly

Adults, 6 mm long with 12 mm wingspan. They have a grey thorax with 3 longitudinal stripes, less pronounced than those of the Common Housefly. The base of abdomen has an extensive yellow patch. At rest, wings are folded along back; venation shows 4th vein extending straight to wing margin. They have an erratic flight pattern and are often seen flying in large numbers around indoor light fittings. The Lesser housefly is more tolerant of cool conditions than the Common housefly.

When the eggs are laid they are about 1mm long and they hatch in 24 to 48 hours. Larval development is 8 days and they have 3 skin moults. Larvae are 6 mm when fully grown. Lifecycle from egg to adult takes about 3 weeks and they breed mainly in poultry manure.

Good hygiene is necessary to limit potential breeding sites and food sources. Entry of adult flies into buildings can be prevented by proofing doors and windows. Spraying alighting surfaces with a residual insecticide will also have some effect. Application of larvacides to animal manure is also a good method of control within agriculture, helping to control infestations at source.

Lesser House Fly