l80 MAINE AGRICULTURAI, EXPERIMENT STATION. I913. 



1912 met a similar fate the preceding year by virtue of Syrphus 

 maggots. Lady bird beetles are also very active some seasons. 

 While in the elm leaf this aphid is preyed upon by vSyrphus 

 maggots, Capsid bugs and lady birds. 



As if the hibernating nymphs were not enough to bcAvilder 

 one, the case of the woolly aphid of the apple is still further 

 complicated by the root colonies which although hidden in their 

 operations really are often much more pernicious than the colo- 

 nies on trunk and branches. These root colonies ordinarily re- 

 main underground all the year round, apparently until the roots 

 become too badly demolished for feeding purposes. 



Economic vStatus. 



The danger from the woolly aphid is greatest to nursery 

 stock and young orchards. Mr. Marlatt (Journal of Economic 

 Entomology, Vol. 4, pp. 116-117) in recording the use of Ameri- 

 can-grown apple seedlings says : — "Mr. E. W. Watson, of To- 

 peka, Kans., in an article in the National Nurseryman for Janu- 

 ary, 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 

 from 20 per cent to 25 per cent of the trees infested by the 

 woolly aphid. 



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 Com- 

 mission 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." 



