MAINE AGRICULTURAL EXPERIMENT STATION. 1 3 



thorough sprayings with kerosene emulsion, diluted with 4 or 5 

 parts of water applied when the trees are dormant is recom- 

 mended in certain localities for this scale. 



Woolly Aphid of the Apple. 

 (Schizoneura lanigera Hausmann.) 



White masses looking like patches of thick mold often occur 

 on apple trees, especially about pruning wounds or other scars 

 on the trunk and branches and upon water sprouts. Beneath 

 this substance are colonies of rusty colored or purplish brown 

 plantlice known as "wholly aphids" on account of the appearance 

 of white covering which is, however, really composed of waxen 

 filaments. 



The species is common in Maine on hawthoi-n, mountain ash, 

 and Baldwin and some other varieties of apple. 



It is one of the migratory aphids and passes part of its life 

 cycle upon the elm, as is explained in the following treatment. 

 It should not however, be confounded with those woolly aphids 

 found upon alder and maple, as the woolly aphid of the apple 

 cannot live upon those trees. 



The woolly aphid occurs upon the apple as a bark feeder 

 and is found upon branches, roots, and tender places on the 

 trunk. These insects are covered by a white flocculent waxy 

 secretion given off as fine filaments through pores in the skin 

 and their colonies are thus readily detected by the masses of 

 white "wool" which renders them conspicuous. Figs. 34 and 56. 



On the roots its attacks induce enlargements and in the 

 creases of these malformations the root form occurs in clus- 

 tered masses. The injury to the trees is due both to the suck- 

 ing up and exhaustion of the vital plant juices and to the 

 poisoning of the parts attacked, as indicated by the consequent 

 abnormal growths. Fig. 35. 



The damage is particularly serious in the case of nursery 

 stock and young trees and is less often important after the tree 

 has once become well established and of some size, though it 

 may be troublesome then, too. Where this insect is abundant 

 all the roots of a young tree to the depth of a foot or so become 

 clubbed and knotted by the growth of hard fibrous enlargements 

 with the results in a year or two of the death of the rootlets 



