66 BULLETIN" 536, U. S. DEPARTMENT OF AGRICULTURE. 



Of the adults kept at 58-62° F. the majority died after the sixth 

 month of life, being caught by the wings in moisture gathering 

 on the sides of the containing jars. , Under more favorable conditions 

 the writers believe that adult life may be extended to cover a full 

 year. 



MATING. 



Martelli first described the mating process. He says that when the 

 male desires to copulate he "seeks to attract the female by curving 

 up and raising the last abdominal segment, then bending the extrem- 

 ity, swelling it to the form of a pinhead, while the venter is drawn 

 back half its length and the abdomen is puffed out laterally, etc." 

 These evidences of sexual stimulation have been verified by the 

 writers. In addition to the dorso-ventral contraction and lateral 

 expansion of the abdomen, the male may vibrate his wings rapidly 

 for periods of 10 to 15 seconds, at the same time that he extrudes the 

 rectum ( ?) to form the white bulbous structure which is held almost 

 perpendicularly over the tip of the abdomen. 



Often the female will move toward the head of the male from the opposite direction 

 to be greeted when within an inch of the male by a violent fanning of the wings of ttie 

 latter. When the female is within half an inch of the male, the male moves forward 

 in a halting fashion until the heads of each almost touch, when the male springs for- 

 ward and endeavors to clasp the female, but is often repulsed. One pair were ob- 

 served to go through this process five times in 30 minutes before copulation occurred. 

 Having once placed himself, the male makes vigorous efforts to bring the tip of his 

 abdomen in contact with the tip of the ovipositor, trying at the same time to grasp 

 the very tip of the ovipositor with the strong chitinized claspers situated on the 

 seventh sternite. The female need only extend the tip of the ovipositor to but a very 

 slight degree from within the last abdominal segment and the male will quickly clasp 

 it and draw it out to a considerable length. The operation of clasping the ovipositor 

 and drawing it out usually takes from 10 to 20 seconds. At the end of 15 to 20 seconds, 

 or even sooner, the long narrow ribbonlike chitinized copulatory organ begins slowly 

 to uncoil from its position. It extends up over either the left or right side of the sixth 

 and seventh abdominal segments and makes one, or sometimes two, loops about the 

 distal fourth with the tip resting under the posterior edge of the fifth tergite. From 

 this position the penis uncoils until the tip comes to a position almost between the 

 claspers, where it enters the vaginal opening. 



Both males and females mate frequently throughout life. One male 

 was observed mating between 3 and 4 p. m., February 3, 1915, and 

 between 11 a. m. and 12 m. and 1 and 3 p. m., February 4. Males 

 observed mating on February 4, 1914, mated again on February 5, 6, 

 7, and 8. Individual females kept for oviposition records have been 

 observed to mate frequently with the males accompanying them. 

 Such data indicate that mating is frequent. Such frequent mating is, 

 however, unnecessary for egg fertility, inasmuch as one female emerg- 

 ing August 12 and observed mating September 8 (probably not for the 

 first time) was isolated on that date and placed with fruit. She 

 deposited 139 eggs between September 16 and November 25, and all 



