TREE INSECTS AND THEIR CONTROL 215 



SAP-SUCKING APHIDS 



Woolly Maple and Alder Aphis 



Habits This insect is more injurious 



and than the cottony maple scale. 



Damage. It shows itself in the early 

 spring as a fluffy mass resemb 

 ling cotton, on the under side of folded 

 leaves, and it looks so formidable as to 

 cause the tree owner much concern. The 

 cottony mass contains aphids hatched 

 from eggs which were laid the previous 

 fall in cracks and under loose bark on the 

 trunk of the tree. At maturity these 

 insects leave the Maple and migrate to an 

 Alder where they produce several genera 

 tions that feed on the bark of twigs and 

 branches throughout the summer. In the 

 fall the final generation returns to the 

 Maple preparatory to the production of a 

 brood which furnishes the eggs for the 

 following season's hatching. Very little 

 injury is caused the Maple. 



Remedies. Because of the relative 

 harmlessness of this insect, 

 treatment is not really necessary. Spray 

 ing with 40 per cent, nicotine sulphate or 

 kerosene emulsion is effectual. 



Norway Maple Aphis 



Habits This insect is found on the 



and under side of Norway Maple 



Damage, leaves during the summer, 

 causing them to show brown 

 blotches. The leaves are also coated with 

 the sticky substance known as honeydew, 

 and so much of this substance is produced 

 that the ground under the tree becomes 

 more or less covered with it. The leaves 

 sometimes fall, disfiguring the tree for the 

 season and impairing growth. The aphis 

 may be recognized by its yellowish green 

 color, with markings of brown, its reddish 

 eyes and long, hairy antennae. 



Remedy. Spraying is usually enough 

 to destroy this insect. The 

 spray should be 40 per cent, nicotine sul 

 phate, mixed with soap and diluted. It 

 should be applied as soon as possible after 

 the insects are discovered on the leaves, 

 and the spraying should be aimed partic 

 ularly at the under side of the leaves. 

 Where an insecticide is not available, a 

 stream of water from a garden hose, 

 applied frequently and with force, will 

 keep this aphid under control. 



GALL INSECTS 

 Gall Insects and Mites 



Habits Several forms of gall-ma k- 



and ing insects and mites infest 



Damage. Maples, causing the growth of 

 galls which disfigure the trees 

 and sometimes cause the premature fall 

 ing of leaves. Serious damage is compara 

 tively rare. 



Remedy. When a tree is badly 

 infested a thorough spraying 

 with kerosene emulsion or miscible-oil 

 solution will prove effectual, if applied 

 during the winter. 



