THE FLIES THAT CAUSE MYIASIS IX MAN 65 



may explain the case of furuncular myiasis described by Mazza and 

 coworkers (87, pp. 70-75), in which four larvae were recovered from 

 a boillike swelling. Larger wounds may become badly infested, and 

 infestation of the navel and vaginal regions may be serious. Infesta- 

 tion of the nasal and frontal regions, and of the eyes, ears, and mouth 

 often result in death, if untreated. Myiasis of the nasal and frontal 

 sinuses is accompanied by excruciating pains and headaches and by a 

 general swelling of that region. 



Literature. — For the taxonomy, see Hall (4-9) ; for biology and im- 

 mature stages. Hall (-£9), Laake. Cushing. and Parish ( 77), and Mazza 

 and coworkers (87) : for case histories. Mazza and coworkers ( 87), and 

 Dove (3b). A large amount of literature on this species has been pub- 

 lished under the specific names C. amerieana, C. honunrcorax, and C. 

 macellaria. 



CALLITROGA MACELLARIA (Fabricius) 



The Secondary Screwworm Fly ; the Common Screwworm Fly 



Synonyms. — Chrysomyia macellaria (Fabricius); Cochliomyia macellaria 



(Fabricius). Many records of this fly in myiasis prior to 1933 refer to C. arm ri- 

 ca nn . 



Recognition Characters. — Adult : This is a green-bodied species with a pre- 

 dominantly orange head. The hair of the lower half of the parafrontals is yellow 

 and of fine texture: distinct outer verticals and one or two distinct, though sin-all. 

 proclinate fronto-orbitals are present in the female, but both outer verticals and 

 fronto-orbitals are absent in the male. The middorsal longitudinal stripe of the 

 thorax does not extend over the scutellum : the fourth abdominal segment is 

 strongly pollinose laterally. Length, 6-9 mm. Larva : The larva is similar in 

 size and general form to that of G. americana; the spines of the integument are 

 smaller, the largest ones averaging about 6 ft in the first instar. 20 /x in the second, 

 and 80 fi in the third : the spines are also paler; the tracheal trunks leading from 

 the posterior spiracles are not pigmented in the second and third instars. Length 

 of mature maggot, up to 17 mm. 



Geographical Distribution. — Nearctic Region : Quebec. Maine. New Hampshire, 

 Vermont. Massachusetts. Connecticut, New York. New Jersey. Maryland. District 

 of Columbia, Virginia. North Carolina. South Carolina, Georgia. Florida. Alabama. 

 Mississippi, Tennessee. Ohio, Indiana. Illinois. Kentucky, Minnesota, Wisconsin. 

 Iowa, Missouri. South Dakota, Nebraska, Kansas. Arkansas, Louisiana. Texas. 

 Montana, Idaho, Colorado, Utah, Nevada, New Mexico, Arizona. Washington, 

 Oregon, California. Neotropical Region: Mexico, Yucatan, Baja California. 

 Guatemala. Honduras, Costa Rica, Panama, Canal Zone, Bahama Islands. Cuba, 

 Jamaica, Haiti, Mona Island. Puerto Rico. Virgin Islands, Guadeloupe, Mar- 

 tinique, Barbados. St. Lucia, Trinidad, Colombia. Galapagos Islands. Ecuador, 

 Venezuela, British, French, and Dutch Guianas, Brazil. Ascension Island, Peru, 

 Bolivia, Paraguay, Uruguay, Chile, Argentina. Patagonia. 



Biology and Pathogenesis. — The eggs are deposited in a yellowish, 

 loosely cemented mass, the number to the mass ranging from 40 to 

 250 up to 1,000 or more. As in certain other Calliphoridae. several 

 females may form composite masses aggregating thousands of eggs. 

 These eggs may hatch in 4 hours under very favorable conditions. 

 The larvae attain maturity in 6 to 20 days, and then leave the breeding 

 medium and crawl into the soil to pupate. The total developmental 

 period ranges from 9 to 39 days, depending on temperature and 

 humidity. The adult lives from '2 to 6 weeks: it feeds on a variety of 

 foods, from garbage refuse to the nectar of flowers. Adults' are 

 usually found in the vicinity of carrion and are most abundant in warm 

 humid areas. 



Numerous records of this species producing myiasis of wounds and 



75 2 113°— 48 5 



