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



ment is rapid, the total period from egg to adult ranging from 10 to 

 25 days. Cool weather favors development ; in the South they become 

 scarce during the hot months, and adults may be found out of doors 

 during the entire winter at least as far north as Iowa. Hibernation 

 apparently takes place in the adult stage. 



Although this is one of the species that has been used in maggot 

 treatment of wounds, it not uncommonly invades healthy tissue. It 

 is a common sheep maggot in the Southwest and in certain localities 

 may be more important as such than CalUtroga americana during the 

 spring and fall months. Cases of traumatic dermal myiasis in man 

 have been recorded; it has also been reported in enteric myiasis, al- 

 though the record needs substantiation. 



The Genus PROTOPHORMIA Townsend 



This is a genus of metallic blackish-green flies of moderate size. 

 The antennae are rather short; the third segment is about twice as 

 long as the second ; the arista is plumose on the basal two-thirds, the 

 plumosity being longer above than below. The mesonotum is flat- 

 tened on the disc behind the suture ; the anterior acrosticals are ves- 

 tigial or absent ; there are four to six, usually five, pairs of postsutural 

 dorsocentrals. The mesothoracic spiracle is dark-haired. The lower 

 squama is bare. The posterior coxae are bare behind. 



PROTOPHORMIA TERRAE-NOVAE (Robineau-Desvoidy) 



Synonyms. — Phormia terrae-novae Robineau-Desvoidy ; Phormia groenlandica 

 (Zetterstedt). 



Recognition Chaeacters. — Adult : This is a dark-blue species with a greenish- 

 blue abdomen and black legs. The front in the male is less than one-fifth the 

 head width ; the bucca is about one-fourth the eye height in the male and one- 

 third the eye height in the female. Length, usually 8-12 mm. Larva: The 

 third-stage larva is similar to .that of Phormia regina, from which it may be 

 distinguished by the characters given in the key. 



Geographical Distribution. — Nearctic Region : Greenland, Ellesmere Island 

 (Lake Hazen), Alaska, Yukon, Labrador, Newfoundland, New Brunswick, 

 Quebec (north to Ungava Bay), Manitoba, Alberta, British Columbia, Maine, 

 New Hampshire, Massachusetts, Rhode Island, Connecticut, New York, New 

 Jersey, Maryland, District of Columbia, Virginia, West Virginia, North Carolina, 

 Georgia (northern), Ohio, Michigan, Indiana, Illinois, Wisconsin, Iowa, North 

 Dakota, South Dakota, Kansas, Texas, Montana, Idaho, Colorado, Utah, New 

 Mexico, Arizona, Washington, Oregon, California. Palaearctic Region : Spitz- 

 bergen. Iceland, Scotland, England. France, Netherlands, Norway, Sweden, 

 Lapland (Swedish), Denmark, Germany, Czechoslovakia, Austria, Hungary, 

 Rumania, European Russia, Siberia (Tolstoinos). 



Biology and Pathogenesis. — This is an early-spring species 

 throughout much of the United States; in more northern localities 

 and at higher elevations it may be common during the summer. It 

 is abundant in Arctic regions and has been taken within 550 miles 

 of the North Pole. 



There seem to be no records of myiasis in man, but this species may 

 be a serious parasite in animals. In Arctic regions it often attacks 

 wounds in reindeer and may cause the death of that animal. It may. 

 produce wound myiasis in sheep and cattle, and it has been considered 

 a primary sheep blowfly in the early part of the season in Scotland. 



