UI.M LEAF CURL AND WOOLLY APPLE APHID. 245 



Kans., in an article in the National Nurseryman for January, 

 1910, p. 437, on "American-grown Apple Seedlings," states that 

 from twenty to forty million of American-grown apple seedlings 

 are used in this country every year, the production of about a 

 dozen nursery firms. The bulk of the seed used comes from 

 France, and therefore is of the same stock as the imported 

 French seedlings." 



Mr. Lohrenz (1911) in recording observations on two-year- 

 old nursery stock made at three nurseries containing respectively 

 about 30,000; 45,000; and 300,000 trees, states that he found 

 frrm 20 per. cent to 25 per cent of the trees infested by the 

 woolly aphid. 



Fig. 445. Fore wing of migrant from elm leaf curl to apple. Third 



Generation. 



In circular No. 20, Bureau of Entomology, U. S. Department 

 of Agriculture (revised edition 1908) the woolly aphid of the 

 apple is characterized as "one of the worst enemies of the apple." 



Mr. Alwood (.1904) of the Virginia State Crop Pest Commis- 

 sion in his excellent account of this insect states "On nursery 

 stock the woolly aphis is a most serious pest, and under some 

 circumstances it ruins a large percentage of the apple trees in 

 the nursery." 



On page 5 of Bulletin 133 of the Colorado Experiment Sta- 

 tion the following statement is made : 



"If Colorado orchardists should vote their opinion as to what 

 ought to be called the worst orchard pest in the state, it is very 



