CHAP. XIII - Diptera (contd.)

Summary

Family Muscidae. (Calypterae.)

Certain species of the ‘ Green-bottle’ flies have acquired the habit of ovipositing on sheep in the region of open wounds or sores. The resulting maggots make their way into the animal where they feed on the flesh with disastrous results. In the British Isles Lucilia sericata Meig. is the chief culprit with possibly L. caesar Linn. A description of two ‘Blue-bottle’ flies Calliphora erythrocephala Meig. and C. vomitoria Linn, is also appended, though it is doubtful if these flies affect sheep in this country to a great extent.

Lucilia sericata Meig. Sheep Maggot Fly; Green-bottle Fly

DESCRIPTION. Adult. Male. Head, frons broad, orbits blackish above, rest of face silvery; antennae black, third joint about three times as long as the second; palpi yellowish. Thorax whitish, hoary, in front are three post-sutural acrostichal bristles. Abdomen, third segment without marginal bristles, forceps rather short. Wings yellowish, squamular piece at base of costa yellowish. Halteres yellowish. Legs black.

Female. Similar, frons broader than eye; thorax distinctly white and hoary in front with the beginnings of two faint median lines; abdomen bluish white, hoary, less shining. Length 6-10 mm. (Lundbeck.)

Egg. Yellowish white, elongate-oval, reticulate with cross ridges.

Larva. Usual muscid type, the posterior face of the caudal segment bears eight large and four small tubercles. Colour white to yellowish. Length 12-15 mm.

Lucilia caesar Linn. Green-bottle Fly

DESCRIPTION. Adult. Male. Head, antennae black; frons narrower than in L. sericata, third joint three times as long as second; palpi yellow. Thoraxwith two post-sutural acrostichal bristles. Abdomen, third segment without marginal bristles. Genitalia somewhat large, forceps rather long. Wings yellowish tinged, squamular piece at base of costa black. Halteres yellow. Legs black; femora bluish.

Female. Similar, frons nearly as broad as eye. Length 6-11 mm. (Lundbeck.)

Calliphora erythrocephala Meig. Blue-bottle Fly

DESCRIPTION. Adult. Male. Head, frons narrow above orbits, grey above becoming silvery; frontal stripe dark; lower part of face reddish, jowls with black bristles; antennae black, third joint long and black hairs below. Thorax dull bluish with a white tinge; there are four indeterminate dark stripes. Abdomen blue, rather shining, third and fourth segments with marginal rows of bristles. Wings hyaline darker at base; veins black or dark brown. Halteres dark. Legs black.