416 p. W. WHITING 



mens may have been a little lighter than the average of my own, 

 for it was the transverse light bands {"strigis 2 obsoLetis dilutiori- 

 6ws" and '^Der erste Querstreifen,. . .heller als die Grundfarbe. . . . 

 Der zweite helle Querstreifen,") rather than the dark, that ap- 

 peared especially to strike his attention. In general later de- 

 scriptions emphasize the transverse dark bands. For example, 

 Miss Ormerod ('89) describes the fore-wings as "pale gray with 

 darker transverse markings." 



The typical ground color of the fore-wings is gray or ashy 

 {"ant. cinereis" and "Grundfarbe hellgrau ohne andere beigemischte 

 Farbe") in my specimens and according to all descriptions 

 available, although Riley ('89) mistakenly says "in the typical 

 specimens raised by Zeller the ground color is pure yellow or 

 nearly brownish." 



I have not been able to correlate with sex any color character 

 such as mentioned by Zeller. The markings of both sexes appear 

 to me to be equally distinct. 



Numerous articles concerned chiefly with the economic im- 

 portance of the moth are referred to in the bibliographies of 

 American economic entomology by Nathan Banks. 



The experiments described in this paper have been carried on 

 by aid of a Harrison Research Fellowship of the University of 

 Pennsylvania. My thanks are due to the members of the Zoo- 

 logical Department for their interest and suggestions. 



B. Source of the material 



The moths used in the experiments belonged to the following 

 stocks : 



Bussey stock. On January 28, 1915, five adult moths were 

 placed in a glass jar 4 inches in diameter and 5 inches high with 

 tin cover screwed down tight. The cover must have admitted 

 but slight circulation of air. The jar was half filled with white 

 flour. It was set in a dark closet at the Bussey Institution, 

 Boston, Massachusetts, and was not disturbed until June 2, 1916. 

 At that time there were many insects in all stages of develop- 

 ment. It is probable that the culture might have lasted much 

 longer as the flour was by no means exhausted. 



