510 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
in this instance the heavily 
infested trees had lost a 
considerable portion of 
their foliage by December, 
the galls all dropping to 
the @ eround. The species is 
widespread and also in- 
fests Frazer fir. The adult 
is not known. 
ACER RUBRUM (RED MAPLE) 
The ocellate maple leaf 
gall (fig. 180) is believed 
to be caused by Ztonida 
ocellaris (O.S. ye although 
there 1s no positive record 
of its rearing. The gall or 
spot, which measures about 
3 to 4 mm. in diameter, is 
yellow and has a red center 
and margin. The larva of 
I. ocellaris is nearly trans- 
parent and lives in an ex- 
posed position on the leaf. 
Figure 129.—Balsam leaf gall caused by Jtonida When full grown, about 
balsamicola, the latter part of Septem- 
ber, the larva drops to the 
ground, where it spins a crude cocoon in which it pupates. The species 
1s widely distributed but rarely, if ever, injurious. Dasyneura com- 
munis Felt, the gouty vein midge, produces greenish or reddish 
pouch vein galls about 6 mm. long. 
ACER NEGUNDO (BOXELDER) 
Ttonida negundines 
(Felt), the boxelder 
gall midge, produces ter- 
minal bud galls with a 
diameter of 1 to 2 cm. or 
long fleshy galls along 
the midrib of the lee if. 
The species is reported to 
have caused serious in- 
jury at Ames, Iowa. 
BETULA (BIRCH) 
Oligotrophus betulae 
(Winn.), the birch seed 
midge, lives in the seed 
of birch, and while it 
dloes not cause any con- 
; s : : KIGURE 130.—Galls on a maple leaf caused by 
spicuous deformity, it Itonida ocellaris. 
1 
