112 MISC. PUBLICATION 631, U. S. DEPT. OF AGRICULTURE 



Region: Ireland, Scotland, Wales, England, Portugal, France, Netherlands, 

 Switzerland, Italy, Sicily, Norway, Denmark, Germany, Austria, Poland, Ruma- 

 nia, Bulgaria, European Turkey, Caucasus. European Russia (widespread, central 

 and southern), Morocco, Algeria, Tunisia, Cyprus, Syria, Iraq, Iran, Inner 

 Mongolia, China, Manchuria. Oriental Region: India (Punjab, Northwest Fron- 

 tier Provinces, Sind), Baluchistan. Ethopian Region: South Africa (on im- 

 ported cattle). Australian Region: Hawaiian Islands. 



Life History and Pathogenesis. — The normal hosts are cattle. 

 Eggs are deposited in rows of 5 to 20 or more on a hair ; they hatch in 

 3 to 7 days, and the larva eventually makes its way to the submucosa 

 of the esophagus, where it remains for a while before resuming its 

 journey to the back. 



In man parasitism by this species is not significantly different in its 

 clinical aspect from that of other members of the genus. Numerous 

 cases are recorded from temperate North America and Europe. 



Literature. — Bishopp and coworkers (18) ; Patton (107). 



The Family OESTRIDAE 



The family is considered here in a restricted sense, equal approxi- 

 mately to the Oestrinae of Pleske (113) and of Rodhain and Bequaert 

 (123) , and to the Oestrini of Townsend's "Manual of Myiology." Most 

 authors use the family name in a much broader sense, to include the 

 Hypodermatidae, Cuterebridae, and Gasterophilidae, or at least the 

 first or the first and second of these. On the other hand, Townsend 

 separates those families from the Oestridae, but includes, perhaps 

 correctly, a number of species of no medical importance which are 

 usually considered larvaevorid. 



As restricted here, the family may be characterized as follows: 

 The head is large, the front being broadly separated in both sexes 

 and the lower parts being rather swollen. Ocelli are present and, in 

 the species treated here, large; the proboscis is greatly reduced, but 

 the palpi are distinctly present. The antennae are short, the third 

 segment being more or less swollen; the arista is thickened basally, 

 thin for the remainder of its length, and bare. The transverse suture 

 of the mesonotum is complete; a distinct postscutellum is present; 

 thoracic bristles are completely undeveloped, the metapleura, sterno- 

 pleura, and hypopleura being clothed only with long hairs. The 

 squamae are large ; the apical cell is closed and petiolate. The abdo- 

 men is rather short and conical, the ventral membrane being distinctly 

 visible. 



The larva is rather robust and not much tapered anteriorly. The 

 third-stage larva has a single pair of mouth hooks; the anterior 

 spiracles are inconspicuous or absent; the posterior spiracles are in 

 the form of two sclerotized plates perforated by numerous pores; the 

 button is present and more or less surrounded by the spiracles ; below 

 the spiracles is a swelling of ambulatory function. 



The larvae live parasitically in the nasal region and frontal or 

 maxillary sinuses of sheep, goats, horses, antelopes, and other hoofed 

 mammals. Abnormally, the species attack man, the larva usually 

 entering the eye capsule or the eye itself, but sometimes the nose or 

 mouth. In man larvae are unable to develop beyond the first stage, 

 probably because they cannot find the proper conditions under which 

 to transform. 



