46 BULLETIN 146, U. S. DEPARTMENT OF AGRICULTURE. 



been broken. The traps were operated during July, August, and Sep- 

 tember, with the following results: 



Clear glass 5S males, 2 females. 



Mottled 2G males. 



Green IS males. 



Blue 15 males. 



Red 



Total males , 117 



Total females 2 



Xeither of the females which were attracted to the clear light con- 

 tained eggs. 



The lights were arranged so that they were about 6 feet from a field 

 of sugar cane. Observations were made to determine whether the 

 number of canes infested by the moth borer had been lowered by the 

 proximity of the lights, but this was not found to be the case, the 

 infestation being as high as usual. 



In 1916 more experiments were conducted, larger traps made on 

 the same principle as those previously employed being fitted with 

 glasses of standardized colors prepared for railroad semaphore lights. 

 The colors used were purple, blue, red, green, brown, and clear. The 

 electric globes were of the same type as those used in 1915. The lights 

 were operated on 54 days from May 9 to September 4, the results 

 being as follows : 



Purple 5 males, 4 females. 



Blue 5 males. 



Red 



Green 6 males. 



Brown . 1 male. 



Clear . 44 males, 2 females. 



Total males 61 



Total females 1 6 



Experiments were conducted also on three nights in September 

 with a 750-watt light taken into a cane field and operated by means 

 of a long extension wire. This was suggested by Mr. E. R. Barber. 

 It was observed that the moths would rise and then settle on the 

 plants again, not continuing to fly around the light. Two males and 

 five females were caught. There was some doubt as to whether two 

 of the females had deposited their eggs, but the remaining three were 

 certainly gravid. 



The operation of lights was also observed on a certain Louisiana 

 plantation on a much larger scale, gasoline torches being pulled 

 about over the plantation. One was equipped with a gasoline engine 

 and other apparatus which caused a powerful suction of air back 

 of the light, the insects being sucked into an inner chamber. The 

 other arrangement was a train drawn on the plantation railway, 



