66 REPORT OF No. 19 



Red-necked Blackberry-borer (Agrilus ruficoUis). 



Symmetrical swellings of the Blackberry cane. The gall is about one- 

 third greater in diameter than the normal cane. The larva makes a chan- 

 nel in the centre of the gall. Occurs on Blackberry. Not common. 



DiPTERA. f. 



0.". 



Vein Gall of Blue Beech (Ceculoniyin pudihiinda) . 



This gall consists of a fold of the leaf along the veins. It is not very 

 much thickened and is generally' constricted near the leaf, forming a long, 

 hollow tube. The opening to the gall is on the underside and runs the full 

 length of the gall. It is lined with white pubescence in much the same 

 way as the Phylloxera on Hickory. Inside the gall, which is hollow, are 

 found a few very small orange-colored larvae. The gall is quite red in color. 

 Occurs on Blue Beech (Carpinus Caroliniana). Common. 



Ball Gall on Wood Nettle (Cecidomyia urnicola). 



This gall is somewhat similar in structure to the gall on the fruit of 

 the wood nettle, but is much smaller, much lighter in color and uniformly 

 monothalamous, whereas the gall on the fruit is sometimes polythalamous. 

 The larvae are also somewhat smaller than those on the fruit. The galls 

 occur either on the upper or lower surface of the leaf. Numerous small 

 inquiline Hymenoptera were hatched from this gall. There is no opening in 

 the gall. Occurs on Wood Nettle {Laportea Canadensis). Common. 



6.9. 

 Pine Cone Willow Gall (Cecidomyia strobiloides). 



A mass of closely imbricated leaves at the end of a twig, caused by the 



arrest of growth at the end of the stem. Regularly cone-shaped. In the 



centre, surrounded by a thin, transparent covering, is a small orange larva. 



Occurs on Salix discolor and many other species of scrub willows. Common. 



. c-^ ■ - 

 Oak Fold Gall (Cecidomyia niveipila). 



Consists of a dense white pubescence upon the under side of the leaves, 

 causing a distortion and folding of the leaf blade. The pubescence is inside 

 the fold, forming the lining, of the gall. Occurs on Eed Oak (Quercus rubra). 

 Common. ^ 



Wild Cherry Bud Gall (Cecidomyia serotinae). 



A club-shaped, monothalamous gall with one or two leaves growing 

 from its sides. The gall is an enlargement of the terminal buds of young 

 shoots of the Wild Cherry. Occurs on Black Cherry (Prunus serotina) and 

 Clink'-cherry (Prunus vtrqiniana). Common. , . ^ 



Eye Spot Gall of Maple (Cecidomyia ocellata). \ ©^wtA^/ 



This is a dimple gall surrounded by an areola. At first the gall is 

 entirely green, but at maturity the nipple tiirns a rich red, the areola sur- 

 rounding it becomes light yellow in color and a thin line surrounding this 

 turns deep pink in color. The successive rings of color very much resemble 

 a target. In the cavity formed by the underside of the gall rests a .small 

 white larva, covered with a viscid secretion. Later in the season the gall 

 turns black and drops out, leaving a circular hole. 



This gall has been usually placed as Sciara ocellata, but most authori- 

 ties, including Osten Sacken himself, now place it as Cecidomyia, attribut- 

 ing the presence of the Sciara to an error in the rearing. Occurs on Red 

 Maple (Acer ruhrum) and Soft Maple (Acer dasycarpum). Common. 



5a EN. 



