4 



CIRCULAR 269, U. S. DEPT. OF AGRICULTURE 



important insect affecting cacao in London. Gibson and Twinn (5, 

 p. 29), writing of Canadian conditions, reported the presence of E. 

 elutella in Canada. Zacher (12, p. 47) recorded the insect as occurring 

 throughout the warmer parts of Europe and extending as far north as 

 the southern part of Sweden. Reports of occurrence in the United 

 States and Canada indicate that this insect has been widely distributed 

 by commerce in these countries. Additional localities from which this 



insect has been re- 

 ported are Africa, 

 Australia, China, 

 and many tropical 

 countries, including 

 Ceylon, Java, Sa- 

 moa, West Indies, 

 Brazil, Costa Rica, 

 and Panama. How- 

 ever, none of these 

 records of occurrence 

 refer to the insect as 

 a pest of tobacco, ex- 

 cept those already 

 mentioned, from 

 Russia, Poland, Bul- 

 garia , Greec e , Af ric a , 

 England, and the 

 United States. 



It will be inter- 

 esting to determine, 

 if possible, whether 

 the infestation in to- 

 bacco warehouses in 

 this country is the 

 result of a foreign 

 importation of Eph- 

 estia elutella that 

 normally feeds on 

 tobacco, or whether 

 the species in the 

 United States, nor- 

 mally feeding on 

 various stored food 

 products, has begun to acquire a taste or preference for tobacco. 



OBSERVATIONS ON STAGES OF EPHESTIA ELUTELLA ON TOBACCO 



THE EGGS 



The eggs of Ephestia elutella are elliptical and are grayish white when 

 laid. Viewed through a binocular microscope, the shells appear to 

 have a granular texture. They are about one-fortieth to one-fiftieth 

 inch long, and are visible to the unaided eye on tobacco leaves. There 

 they are laid either singly or in small clusters. A small cluster of eggs 

 attached to a leaf of flue-cured tobacco near the midrib is shown in 

 Figure 2. The eggs, when deposited, have soft shells which harden 

 soon after exposure to the air. In clusters they sometimes press upon 



Figure 2.— Eggs of Ephestia elutella laid near th 

 flue-cured tobacco. X 25 



midrib of a leaf of 



