BEHAVIOR. 7 



around toward her. He sometimes goes to the other side, but usually 

 circles rapidly to the rear. No wing-motion by the male has been 

 seen when he was in any position but the above. When he circles to 

 the rear, the female may spread her wings as in D. funebris. The male 

 then rushes in and copulates. One pair in copula 2 minutes. 



Drosophila obscura: Vibration (both wings at once), scissors move- 

 ment, circling, male genitalia go up underneath. The female does 

 not spread her wings. In copula 4, 5, 5, 6, 6, 6, 6, 7, 7, 8, 8, 11 

 minutes. 



Drosophila repleta: Scissors movement, licking; no vibration or 

 circling. The female spreads her wings as in D. funebris, but not so 

 widely. After the genitalia become separated the male remains in 

 position for about 30 seconds. One pair copulated twice within 10 

 minutes. In copula 2, 3 minutes. 



Drosophila robusta: Scissors movement, waving, licking; no vibra- 

 tion or circling. The female does not spread her wings before the male 

 mounts. In copula 2 minutes. 



Drosophila simulans: Vibration, scissors movement, circling, licking, 

 male genitalia go up underneath, female does not spread her wings — 

 all as in D. melanogaster. In copula 19, 20, 23, 25, 25, 32, 32, 36, 

 48 minutes. 



Drosophila transversa: Scissors movement, rapid waving, circling, 

 licking. No vibration seen. Copulation itself not observed. (These 

 notes possibly refer to D. putrida.) 



Drosophila virilis: Scissors movement, waving, licking; no vibration 

 or circling. The female spreads her wings before the male mounts. 

 If he fails to mount she keeps them apart a few seconds. The male 

 genitalia go up underneath. Mounting is done slowly. In copula 

 2, 3, 4, 4, 4, 5 minutes. 



Drosophila willistoni: Scissors movement, licking; no circling or 

 vibration seen. In copula 27 minutes. 



Drosophila hypocausta Osten Sacken: De Meijere (1914. Tijds. v. 

 Entom., 54) has given notes from Jacobson showing that courtship in 

 this oriental species is accompanied by circling and licking. 



Scaptomyza adusta: Very little courtship, all done from behind the 

 female. Occasional scissors movement, slight vibration, not much 

 licking, no circling. Male rushes at female and doubles his abdomen 

 up underneath; usually fails to mate. The female does not spread 

 her wings. Mounting does not occur until the genitalia are connected. 

 The final position is the same as in most species of Drosophila. In 

 copula 8 minutes. 



Scaptomyza graminum: Same as S. adusta. In copula 3 minutes. 



Chymomyza amcena: None of the characteristic acts of courtship in 

 Drosophila seem to occur in this genus, except that a modified waving 

 is constantly being done by both sexes even when not sexually excited. 



