212 Maine Agricultural Experiment Station. 1917. 



If one compares the total number of male and female currant 

 fruit flies captured in shady localities during the morning and 

 afternoon on the dates when no rain fell, it is evident that more 

 males were caught during the forenoon {27^(^ A. M., 1S7(^ 

 P. M.), but more females were collected during the afternoon 

 (99$ A. M., 214$ P. M.). A similar comparison of the number 

 of specimens taken in copula on these dates shows that 20 pairs 

 were captured in the forenoon and 37 pairs during the afternoon. 



Effect of Sunshine. 



On several occasions currant fruit flies which had been cap- 

 tured in phials in the field were left accidentially in the sunshine 

 and the exposure usually resulted in the death of the specimens. 

 In order to obtain accurate data on the effect of temperature 

 on the trypetids, five male and five female flies were exposed to 

 sunshine in corked phials at 100° F. and within 10 minutes all 

 of them were dead. 



Death Feint. 



The recently emerged trypetids with wings not yet expanded 

 can be induced to feign death. To bring about this inert condi- 

 tion, the fly was suddenly turned upon its back with a camel's 

 hair brush or when disturbed the insect may hop, drop to the 

 ground and feign death. Some specimens could be placed in 

 6 successive feints. The duration of the successive feints varied 

 from a few seconds to three minutes. The termination of this 

 immovable state was preceded by a twitching of the legs. A 

 gust of wind or a breath of air caused an immediate awakening. 



Marking Flies. 



A number of different methods were used in marking cur- 

 rant fruit flies so that they might be recognized in the field. As 

 already mentioned one method employed was to amputate part 

 of a leg. A phial containing one adult was turned with the open 

 end down and the bottle was then tapped with the finger over a 

 small tablet of white paper coated with diluted corn syrup upon 

 which the insect usually began to feed. The tablet was then 

 turned in the desired position and a leg was snipped in two 



