NEW YORK STATE MUSEUM 



DKSTKl'CTIVK .SIX'KINO INSECTS 



Tile work of sucking insects is easily distinguished from that of other 

 classes because in no case is tissue removed. Their operations are usually 

 followed by shrinking, discoloration, and decay. 



Key to destructive sucking insects 



Small, many with liinilol locomotive powers 



Leaves, species found on foliage only 



Yellowish green, brown marked aphids or plant lice occurring in clusters on the 



underside of Norway maple C h a i t o p h o r u s a c e r i s, p. 174 



A pretty winged, red eyed, black and white marked jjlant louse, together with pale 

 yellowish, wingless young, may be found on the under surface of soft maple leaves, 

 specially on those near the tips 



Painted maple aphid, I) r e p a n o s i p h u m ac e r i f o 1 i i, p. 175 

 A slight, inconspicuous plant louse on the underside of American elm leaves 



Elm leaf aphid, Ca 1 1 i p t e r u s u 1 m i f o 1 i i, p. 176 

 Curled and gnarled leaves of white elm in June, with whitish pellets of honeydew 

 dro])ping from the tree 



Woolly elm leaf a]ihid, Schizoneura a m e r i c a n a, p. 177 

 Sugar maple leaves bearing numerous cottony masses protruding from under brownish 



scales Maple leaf scale, P u 1 v i n a r i a a c e r i c o I a, p. 179 



Cottony white insects on the under surface of sugar maple leaves and masses on tb.e 



trunk Maple Phenacoccus, Phenacoccus acericola, p. 182 



American elm leaves deformed by a peculiar cockscomblike gall in June. 



Cockscomb elm gall, C o 1 o p h a u 1 m i c o 1 a , p. 186 

 Snow white, woolly plant lice on larch needles in May and June 



AVooIIy larch aphid, C h e r m e s s t r o b i I o b i u s, p. 1 87 

 Somewhat cone-shaped, many-celled galls at the base of young spruce shoots 



Spruce gall aphid, Cher ni e s a b i e t i s, p. 189 

 Small, yellowish white, jumping insects about '/,o inch long occur in swarms during 



midsummer, on rose leaves Rose leaf hopper, Typhlocyba r o s a e, p. 191 



Bark, ajihids or plant lice and scale insects on limbs or trunk 



Species with more or less flocculent matter 

 Clusters of white woolly substance on elms and trunks of white elm 



Woolly elm bark aphid, Schizoneura r i 1 e y i, p. 192 

 Patches of flocculent, downy matter on the smooth bark of white pine 



Pine bark aphid, Cher in e s p i n i c o r I i c i s, p. 192 



