258 NKW VOKK .STATK Ml'-SEUM 



Forming galls on or killing willow shoots 

 European willows are attacked by a small, black midge wiiich produces irregular, some- 

 what fusiform galls inhabited by yellowish jumping larvae 



Kuropean willow gall midge, R h a b d o p h a g a s a I i c i s, p. 299 



Sudden wilting of terminal shoots may be caused by a sawfly girdling the twigs after 



depositing her eggs Willow shoot sawfly, Janus integer, p. 302 



Leaf feeders 

 Reddish, white striped or black, white haired caterpillars from J^ to 1I2 inches in length, 

 feed in large clusters in midsummer on black walnut and other trees 



Black walnut caterpillar L) a t a n a i n t e g e r r i m a, p. 303 



A large, bluish green caterpillar with four conspicuous hornlike projections on the thoracic 



segments and a number of smaller ones, o< curs in September on hickory and other 



trees Hickory horned devil, C i t h e r o n i a r e g a I i s, j). 305 



Blai k spiny caterpillars with 4 orange yellow stripes on the back and 2 along each side, 

 fretiuenlly strip the foliage from scrub and other oaks in August 



Yellow striped oak caterpillar, A n i s o t a s e n a t o r i a, p. 306 

 Small, black, spiny caterpillars occur in early summer, feeding in comjiany on the leaves 

 of various oaks, particularly in swampy ])laces 



Buck or mala motli, H e m i I e 11 c a m a i a, ]). 310 

 Snow white, black dotted, black tufted caterpillars occur in (lusters during July, August 

 and September, on the tender leaves of hi( kory anil other trees 



lli< kory tussock moth, H a I i s i d o t a c a r y a e, p. 314 

 Leaves of white birch are sometimes skeletonized by a small, pale green caterpillar, 'the 

 foliage turns brown the latter part of tlie summer, and the small, brownish yellow, 

 ribbed cocoons serve to identify the depredator 



liirih leaf skeleloiii/er, B u < c u 1 a t r i x c a n a d e n s i s e 1 I a, ]). 315 

 Yellowish beetles or blackish grubs about -■« inch in lengtli, freijuently defoliate willows 

 and poplars, speciallv in the Western States 



Cottonwood leaf beetle, M e I a s o m a s c r i j) t a, p. 317 

 Greenish black sawtly larvae about V',„ inch long and with heart-shaped, yellowish spots 

 on each side, detoliate willow and ])oplar 



Yellow-spotted willow slug, P t e r o n u s v e n I r a I i s, ]). 322 

 Blisterlike s|)ots or eroded, skeletonized areas on honey locust leaves 



Locust leaf miner, O d o n t o t a d o r s a I i », p. 325 



Sucking insects 



A circular, convex, briglit yellow or golden scale insect about '/,6 inch in diameter, some- 

 times occurs on oak twigs in verv large numbers 



Ocilden oak scale, A s t e r o 1 e c a n i u m va r io 1 osu m, p. 329 



