336 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 15 



Observations on the behavior of the moths while ovipositing also 

 indicate that they manifest at least a slight preference for the silks. 

 More time is usually spent on the silks and it is not uncommon for the 

 moth to deposit several eggs before leaving. The time spent on the 

 other parts of the plant is usually very brief, and seldom more than one 

 egg is deposited in a place. It might also be mentioned that the adults 

 do not make use of the silks as a source of food, except possibly when the 

 latter are saturated with moisture. 



A study of these data suggested the possibility of a chemotropic 

 response of the adult through the olfactory senses since the silk does 

 possess a distinct odor. During the past three years certain preliminary 

 experiments have been undertaken on the odor of corn silk as an attrac- 

 tion for the earworm moths. Imitation silks were made by taking 30 

 or 50 strands of cotton twine or yam about 9-10 cm. in length and tying 

 them together at one end. These were then impregnated with the odor 

 of corn silk by soaking in juices obtained by crushing fresh silks every 

 evening. In the following discussion these are spoken of as treated 

 silks. Other sets were prepared identical with the above, except that 

 they were not soaked in the juices and these are designated as checks. 

 During 1919 and 1920 these imitation silks were placed in pairs on 

 opposite sides of com plants which bore no ears and were attached to the 

 plants about 90 cm. above the ground. In 1921 they were placed on 

 stakes set about in the com field in order to eliminate any attractive 

 effect which the corn plants might have on the results. Seventeen pairs 

 of imitation silks were used during the three years and the results are 

 presented in Table III. 



Table III. — Showing the Number of Eggs Deposited ox the Imitation Silks, 1919-1921. 



E.xperiment Period 



No. 



1 Aug. 11— Sept. 9 , 1919 



2 " " 



3 " ■' 



4 " " 



5* " " 



6 Aug. 27— Sept. 29, 1920 



7 " " 



8 Sept. 1 " 



9* " " 



10 " " 



11 " " 



12 Sept. 4 " 



13 " " 



14* Aug. 8— Sept. 19. 1921 



15* " " 



16* " 15 " 



17* " " 



367 97 79.1 



*Placed on stakes removed from corn plants. 



