Calliphoridae 413 



amerkana [see p. 416], except that the meat is changed daily. During 

 copulation many of the pairs fall to the floor of the cage, and if the 

 meat is slightly decomposed the flies that fall on it become stuck and 

 die. 



Larvae are deposited on the meat, but since each female deposits only 

 a few larvae per day it has been found advisable, especially when a large 

 culture is desired, to catch the females individually and squeeze the larvae 

 out. By the squeezing method 50 or more larvae are obtained from 

 each female, whereas if allowed to deposit normally from 9 to 15 larvae 

 are obtained per female per day. The objections to squeezing the females 

 are that the larvae vary slightly in size and that the females are killed. 



Once the larvae are obtained, the method of handling is the same as 

 that for larvae of Cochliomyia macellaria. 



Family calliphoridae 



COCHLIOMYIA AMERICANA AND C. MACELLARIA 



Roy Melvin, U. S. Bureau of Entomology and Plant Quarantine 



THE fly, Cochliomyia amerkana, has been reared in captivity for 12 

 consecutive generations by the following method. 



Feeding and care of adidts. The cage for the adults is constructed 

 as follows: The bottom consists of a 1" x 12" board 17% inches long 

 and is nailed to a 1" x 12" board 11 inches long, which forms one end. 

 The upper corners of this end are rounded to prevent the wire from 

 breaking. A small angle-iron is used to add rigidity. The end and bot- 

 tom are then painted to prevent warping. A piece of 16-mesh galvanized 

 screen wire 18 inches wide is tacked along one edge of the bottom and 

 stretched completely around and tacked to the wooden end, to form the 

 2 sides and top. A cloth sleeve is sewed into the other end. 



Water is supplied by means of a fountain consisting of a jar, with a 

 small groove filed in the lip, filled with water and inverted in a saucer 

 containing a small cloth disk. Bananas are halved and placed in the 

 cage. A small piece of lean beef, to which a few cc. of water are added, 

 is placed in a saucer in the cage during the pre-oviposition period. Once 

 daily honey is strung along the cage by means of a straw. Since the 

 adults of this species are very clumsy, care should be taken to prevent 

 the honey from dropping to the floor of the cage where the flies are likely 

 to become stuck in it. 



Feeding and care of immature stages. The eggs are obtained by plac- 

 ing gravid females in vials containing small strips of lean beef and 

 plugged with dry cotton. The optimum temperature for oviposition is 



