216 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 15 



1. They require attention twice daily. 



2. They are somewhat expensive to operate. 



3. They are practically ineffective diiring periods of full moon. 



4. They are not well adapted to a windy country. 



5. For the species under consideration they catch too small a 

 percentage of fem.ales. 



Molasses Troughs 



This method was suggested by the experiments conducted by Do- 

 brovljansky^ for the control of E. segetimi in Russia. Early in Septem- 

 ber 1920, three galvanized iron troughs, 2 feet long and 6 inches wide 

 and deep, were set out in a badly infested area. Each was half filled 

 with a 66% solution of molasses in water. On the first night they 

 captured a total of 382 moths of which 135 were females of P. orthogonia. 

 A slight crust had formed on the surface of the molasses by the following 

 night when 16 moths only were retained. Of these 8 were females. 

 It was obvious that we mig.ht be attracting to the field moths that we 

 were unable to captiu^e and that possibly our troughs were doing more 

 harm than good to the owner. 



Attempts to im.prove the consistency of the molasses solution failed 

 to give satisfactory results. In a 50% solution many m.oths swam 

 to the sides and escaped while any stronger solution crusted over in 

 a very short time. Some twenty troughs were used in 1921, and 

 attempts were made to retain the moths in weak solutions by the ad- 

 dition of vegetable and other oils, with tanglefoot and with poisons, 

 but without success. 



This method was early abandoned for the following reasons: 



1. The troughs require very frequent attention. 



2. A great many of the moths escape. 



Poisoned Molasses 



P. orthogonia comes very readily to "sugar" applied to fence posts. 

 A fence post can be kept permanently "sugared" every evening for from 

 ten to fourteen days by means of a simple apparatus. The only material 

 required is a quart bottle with a cork to fit, 6 inches of lamp wick and 

 a small piece of absorbent cloth. The bottle is filled with the sugaring 

 mixtiire and the end of the wick, which has first been well saturated 

 in the mixture, is inserted. A well fitting cork, that has been slightly 

 flattened on one side by cutting away a small portion with a knife is 

 pressed fairly tightly into the bottle with the flattened side next to the 

 wick. The bottle is then inverted and wired or tied to the west side 



lExtract in Rev. Applied Ent., Series A. Vol. 1, p. 490, 1913. 



