THE POTATO TTJBEE MOTH. 3 



POSSIBLE ORIGIN. 



A study of the literature shows that the tuber moth was known to 

 be present ahnost simultaneously in Australasia, the United States, 

 and Algeria. It is indeed strange that, considering this fact and, in 

 addition, the fact that this country is the home of a wild potato 

 and tobacco, of all the entomologists who have studied the tuber 

 moth, only one, Gerald McCarthy (31), who found the tuber moth 

 mining tobacco in North CaroHna in 1897, should claim that this coun- 

 try is its native home. McCarthy also found the moth in Solanum 

 carolinense, a native weed common in the southeastern part of the 

 United States. Speaking of the tuber moth, he says, "This insect 

 probably inhabited its present range prior to the coming of the white 

 man." 



Dr. Picard (83, 84), a prominent authority on this insect, says that 

 a Mediterranean origin for this species must be excluded. Consid- 

 ering the fact that he has not found a specific natural enemy, in the 

 shape of a parasite, on the insect, his opinion must be given consider- 

 able weight. He mentions either Australia or the United States as a 

 possible origin for the tuber moth. 



Analyzing the facts as presented by these two countries, it is seen 

 that it was reported from both places at practically the same time. 

 Edw. Meyrick, one of the earher authorities on the Microlepidoptera, 

 states that it is not an Australian form. In addition, there is no 

 mention of any natural enemies of the species, which is quite signifi- 

 cant, considering that many competent entomologists have worked 

 on it in Australia. 



On the other hand, in the United States there are several parasites 

 on the tuber moth, and, as previously stated, this country is the home 

 of a wild potato and tobacco, its two favorite food plants. When it 

 is considered that it was not until the sixteenth century that the 

 potato was introduced into Europe, and that it was not until many 

 years later that the use of the potato became at aU general, it seems 

 only reasonable to suppose that the rapid dissemination of the tuber 

 moth came about by following the potato "around the world." 



Furlh<'rmore, the tuber moth is an insect which could be introduced 

 easily from one locality to another, as once it infests potatoes it is 

 assured of food enough to carry it through several generations; and 

 as the insect fan stand lower temperatures than the tubers, it would 

 never be in danger of being killed by freezing. 



The ontiro economic history of the tuber moth is another indication 

 that it r)riginal('d in America. Losses reported to })()tato cr<)])s in Al- 

 geria, India, Tasmania, South Africa, Australia, and New Z(^aland 

 are far .heavier than any ever reported from California or Texas. 

 Clirnalie, eDiiditiotis being efjnal, it is generally tnie tlint a ])est is nion^ 

 injurious in an adopUid home, for a tim<; at least, than iji its natural 



