2 BULLETIN 59, U. S. DEPAETMENT OF AGKICULTUKE. 



Larvae of the potato-tuber moth were reared on potato tubers 

 and on the foliage of Solarium carolinense, eggplant, PJiy ' sails sp., 

 Datura stramonium ("jimsonweed"), and tobacco; they also mined 

 the leaves of Solarium nigrum until the plant died. Larvae of the 

 tobacco splitworm moth were reared on potato tubers and on the 

 foliage of Solarium carolinense, eggplant, PJiysalis sp., PJiysalodes 

 pJiysalodes, Datura stramonium, and tobacco. There was no per- 

 ceptible difference in the period of development, in habits, or in 

 behavior of the two forms on a given food plant that could be ascribed 

 to the different origins of the individuals. A male potato-tuber 

 moth of the habitual potato-feeding type and a female splitworm 

 moth of the habitual tobacco-feeding type, reared from isolated 

 pupae and caged together, produced larvae that reached maturity 

 upon tobacco. 



The earliest stages of the two types show no appreciable differences 

 except in the case of the larva, and here the differences, excepting 

 size, are entirely colorational. The larva on potato is larger, grayish, 

 and has the mesothorax and metathorax pinkish, while the habitual 

 tobacco feeder is green and has the mesothorax and metathorax deep 

 maroon. By reversing the two food plants the larvae can be made to 

 approach each other in coloration, but even after two generations on 

 tobacco the habitual potato feeder is less green and has the thorax 

 distinctly paler than the habitual tobacco feeder; also, the coloration 

 of the latter type persists when reared upon potato tubers. The 

 larvae of the crossed moths were intermediate in coloration between 

 the two types just discussed. 



The rather persistent color variation noted in the two larval types 

 under discussion, while probably of sufficient constancy to warrant 

 a varietal separation, is not, the writers believe, of sufficient impor- 

 tance to justify a specific separation. 



Potato-tuber moths reared from potato are usually somewhat 

 larger than splitworm moths reared from tobacco. This difference 

 disappears when the potato-tuber moth is reared on other plants. 

 Potato-tuber moths reared from potato tubers, PJiysalis sp., Solanum 

 carolinense, tobacco, and Datura stramonium, and splitworm moths 

 reared from tobacco, potato tubers, and PJiysalis sp., were submitted 

 to Mr. August Busck, who reported that he could find no specific 

 differences. 



DISTRIBUTION. 



In the United States the species occurs in California and southward 

 from a fine connecting the District of Columbia and Colorado. The 

 definite localities include Tennessee, Virginia, North Carolina, South 

 Carolina, Florida, and Texas. Reports of more northern occurrence 

 are probably due to the shipment of infested potatoes into these 



