24 INSECT-GALLS OF THE VICINITY OF NEW YORK CITY 



DIPTERA (Flies). 



Family Cecidomyiid.^ (Gall-gnats). 



The members of this family are minute flies with the wings 

 and body clothed with long hairs. The larvae are small brightly- 

 colored maggots, being red, pink, yellow or orange. 



48. Willow Egg Gall {Eiiura ovum Walsh). — Oval or elongated. Placed 

 lengthwise on one side of a twig, often in a row of two or more. Hard and 

 woody. On the stems of bush willow growing in swampy places. Rather 

 common. 



49. Alder Bud Gall {Cccidomyia serrulated Osten Sacken). — Rounded, 

 bud-like, with the apex pointed, and often covered with a whitish bloom. 

 Greenish in autumn and brown in winter. This gall is a deformation of the 

 terminal bud of the common alder (Alnus rugosa). Rather common locally. 



50. Basswood Weirt Gall {jUectdomyia vcrructcoia Osten Sacken). — Rounded, 



