FOOD PLANTS. 293 



Before 1873, however, Mr. Grote had discovered that Heliothis armi- 

 gera was a very variable species, and that what he had described as H. 

 unibrosus in 18G3 was simply one of its varieties. He therefore noted 

 the fact in the bulletin of the Buffalo Society of Natural Sciences, Vol. I, 

 p. 120. He there says : 



While a comparison of American specimens (unibrosus) with European individuals 

 (armigcra) affords me no apparently valid distinguishing characters, yet I remark that 

 the larvae have not yet been compared. I am not yet prepared to believe that the 

 species has been introduced from Europe, feeding, as it does here, on some peculiarly 

 American genera of plants. 



Some time previous to this, Mr. Glover had acknowledged the identity 

 of the European and American insects in the Department of Agricul- 

 ture Reports, as also had Walsh and Riley in the American Entomolo- 

 gist, and Riley in the Missouri Entomological Reports. 



GEOGRAPHICAL DISTRIBUTION. 



We shall not enter into the discussion as to the original habitat of 

 the boll-worm, as such would necessarily prove fruitless on account of 

 the insufficiency of the data. Mr. Grote goes on to say : 



Yet, according to Guene"e, its habitat is very extended, since it has been taken in 

 Australia, where, however, it has been introduced since the colonization, and from 

 America. It occurs apparently rarely in Europe, whereas it is here common. Has it 

 reached Europe by a westward route from California ? We shall probably soon write 

 after its habitat the world! 



It is a suggestive fact, reflecting upon Mr. Grote's conclusion, that the 

 earliest mention of the boll-worm in this country which we have found 

 is 1841, whereas Huebner described the European form prior to 1825. 



As above stated, the geographical range of the species is very great. 

 Mr. Bond, at the March 1, 18G9, meeting of the London Entomological 

 Society, exhibited specimens from the Isle of Wight, Java, and Austra- 

 lia, and these localities, taken in connection with other parts of Europe 

 and the United States, seem to justify Mr. Grote's prediction. 



FOOD PLANTS. 



For many years it was not known that the destructive corn-worm and 

 the cotton boll- worm were the same insect. It was suspected by many 

 before actually demonstrated, but is even now unknown to the majority 

 of agriculturists. The first record of the identity of the two insects 

 which we have been able to find is in the Department of Agriculture 



Under surface of the wings pale, showing the black discal spot on the anterior wings 

 plainly, outside of which is a blackish transverse band and a small blackish streak 

 near the upper margin. Under surface of post wings immaculate, except a faint 

 blackish shade near the outer margin. Head, thorax, and tegulae yellowish-gray, 

 darker than the anterior wings. Body grayish, clothed at the sides with whitish hairs 

 and darkening towards the tip. Exp. 1^ inches." [Proc. Ent. Soc. Phila., vol. 1 

 (1861-1803), p. 219. 



