PLATE 4 



Midge galls 



i Variable twig swellings on wild cherry produced by midge 



larvae working in the subcortical layers, adult not reared 

 i a Section of such a deformity 



2 An older type of gall than that represented in i 

 2a An old scar in process of healing 



3 Leaf gall of Lasioptera farinosa Beutm. on black- 



berry 

 3a Early stage of same gall showing reddish discoloration 



4 Irregular twig galls ofCecidomyia c i t r i n a O. S., adult 



not reared 



5 Early stage of leaf stem gall on Linden, probably produced 



by Cecidomyia v e r r u c i c o 1 a O. S., adult unknown. 

 Compare with figures 8 and 8a on plate 2 



6 Globular green gall on Linden leaf. See under 5 



7 Bud gall on Spiraea salicifolia produced by Hor- 



momyia clarkeae Felt 



8 Tubular gall on the under surface of the leaf of Cornus 



paniculata produced by Cecidomyia tuba 

 Stebb., adult unknown 



9 Galls along the under side of the midrib of the bitternut 



hickory produced by Caryomyia caryaecola O. S. 



10 Enlarged bud gall on Rudbeckia produced byAsphondylia 



conspicua O. S. 



1 1 Apical bud gall on solidago produced by Rhopalomyia 



h i r t i p e s O. S. 



12 Midrib swelling on Spiraea tomentosa produced by 



Rhabdophaga salicifolia Felt 



13 Side view of a gall on willow leaf produced byHormomyia 



verruca Walsh 



14 Cluster of older galls on willow leaf produced by Hor- 



momyia verruca Walsh 



15 Flower bud galls on Eupatorium purpureum pro- 



duced by Dasyneura purpurea Felt 



16 Fringed terminal bud gall on Spiraea salicifolia, 



adult unknown 



17 Leaf of shadbush, Amelanchier canadensis de- 



formed by Hormomyia canadensis Felt 



