8 BULLETIN" 42*7, U. S. DEPARTMENT OF AGEICULTUBE. 



but where potatoes are not habitually stored, the tuber moth is more 

 in the nature of an annoying pest, causing minor losses practically 

 every year, but becoming of primary importance only where condi- 

 tions favor its increase. Careless planting, late and slow harvesting, 

 and poor markets with the consequent holding back of the crop, would 

 bring about such conditions. 



The tuber moth is reported to have done much injury to potatoes 

 in Tasmania in 1855, and it was then stated that it ''has of late years 

 been making ravages amongst tubers in New Zealand" (1). 



In 1875 it was reported to have been injurious for the preceding 

 years in Algeria. Specific instances give the losses at El-Bear as 

 three-fourths of the entire crop (6). Meyrick (9) mentions large 

 losses caused by it in Australia in 1878-79, and gives an authenticated 

 case where four-fifths of the crop in one field was destroyed. The 

 tuber moth was reported as destructive to potatoes in California in 

 1881 and 1882 (13), and in 1901 (37). 



In 1897 the tuber moth was noted mining in tobacco in North 

 Carolina (31) and in 1899 was mentioned as being destructive to 

 tobacco and eggplant in Florida (33). In 1898 it was reported from 

 South Africa as being common in potatoes, but, due to the fact that 

 the potatoes were marketed very quickly, seldom causing much damage. 

 Literature further records damage by the tuber moth in India in 

 1906 (62). 



In Australia, India, Tasmania and New Zealand the damaging 

 outbreaks have been of periodic occurrence from the time the tuber 

 moth has been reported. Usually some explanation is given for 

 this condition, and it is noticeable that the outbreaks generally occur 

 during dry years. Authorities seem to agree that the tuber moth is 

 a dangerous pest only to stored potatoes. 



This probably explains why the tuber moth attracts so little at- 

 tention in the United States, where it has long been present. In the 

 warm, dry sections potatoes are never habitually stored, and as 

 these districts supply early potatoes for the neighboring States, 

 under normal conditions the entire crop is harvested as early as pos- 

 sible. 



Records of the Los Angeles County Horticultural Commission show 

 that the importation of potatoes is twice as great in the fall as is the 

 exportation in the early summer. This alone shows that normally 

 potatoes once harvested are not held sufficiently long to permit in- 

 festation by the moth, or once infested they are used up before their 

 food value is materially impaired thereby. The tuber moth can 

 become of importance only during times of poor market conditions, 

 when the potatoes are held for a rise in price. 



