The larvæ are frequently found in the nostrils of man and burrow into the sinus, but normally they live on decaying animal matter.
Pycnosoma forms the so-called Indian screw-worm. Patterson (Ind. Med. Gaz., October, 1909, xliv, No. 10) records the case of a woman at Tezpin, Assam, from whom as many as 100 larvæ were removed at one time, and later the left orbital cavity was found packed with hundreds of maggots; eventually the patient died. It is possible that this, however, was due to a species of Sarcophaga. Austen undoubtedly records this genus causing nasal myiasis in India (Trans. Soc. Trop. Med. and Hyg., iii, p. 235). At Dehra Doon, U.P., a woman discharged 100 larvæ from her nose, with great pain in the nasal region and frontal sinuses.
The so-called “peenash,” a common malady in Rajputana, is a true nasal myiasis.
Genus. Sarcophaga, Mg.
Sarcophaga carnosa, L., 1758.
Larvæ of flesh-flies provided with two claws at the anterior end, which settle on raw or cooked meat, and in the open on carcases of animals; they are often observed in man, both in the intestine (introduced with food) and in the nasal cavities, frontal sinus, conjunctiva, aural meatus, anus, vulva, vagina, prepuce, and open ulcers, often migrating further from the regions first attacked. (Gayot in Compt. rend. Acad. Sci., Paris, 1838, vii, p. 125. Grube in Arch. f. Naturg., 1853, xix, 1, p. 282. Legrand du Saulle in Compt. rend. Acad. Sci., Paris, 1857, xlv, p. 600, and other authors.)
[This fly is viviparous. The fly varies from 10 to 30 mm. in length, and is of a general ash-grey colour; the thorax with three dark stripes, the abdomen light grey with three black spots on each segment; legs black; base of wings yellow. It also attacks animals and birds, especially geese. The genus Sarcophaga is universally distributed. The maggots are whitish or yellowish footless larvæ of twelve segments, tapering to a point in front, broadened posteriorly. There are two mouth hooks, by means of which they rasp their food. The breathing pores are at the end and consist of two groups of three slits, each surrounded by a hardened area. They pupate in their old skin, which turns brown.—F. V. T.]
Sarcophaga magnifica, Schiner, 1862.[412]
Syn.: Sarcophaga wohlfahrti, Portschinsky, 1875.