1082 WALTER H. WELLHOUSE 
Fic. 116. THORN COCKSCOMB GALL 
White larvae, 3.5 millimeters 
long and with a distinet brown 
breast-bone, were found, one in 
each gall, in June. 
crataegifolia Felt, Hormomyia 
(Thorn cockscomb gall) 
Green or red cockscomb-like 
galls (figs. 116 and 117) produced 
by Hormomyia crataegifolia are 
found on the upper or the lower 
side of leaves of Crataegus pru- 
inosa, C. macrosperma, and C. 
coccinea. They are often in groups 
on a leaf or a cluster of leaves, and 
each gall includes a vein. The 
gall is from 8 to 12 millimeters 
long and 5 millimeters high, and 
is open to the outside by a long, 
narrow slit on the opposite side 
of the leaf. These galls are found 
in August. 
venae Felt, Lobopteromyia (Thorn 
vein gall) 
Round or oval, thick-walled, 
green galls (figs. 118 and 119) from 5 to 8 millimeters long, produced by 
Lobopteromyia venae, are found on either the upper or the lower surface of 
leaves of Crataegus punctata. The gall opens on the opposite side of the 
leaf by a narrow slit which extends the entire length of the gall in the 
direction of the vein. It always includes one of the larger veins. The 
galls are fairly abundant in June, when several may be found on one leaf 
and all the leaves in a cluster are deformed. 
Cecidomyia sp. (a. 1840 Felt) 
(Thorn spindle gall) 
Red or green, elongate 
spindle-shaped galls (figs. 120 
and 121) 2 millimeters wide 
and from 5 to 10 millimeters 
long, produced by Cecidomyia 
sp., are found on either side 
of the leaves of Crataegus ree alle 
punctata. The gall opens by 
CROSS SECTION THROUGH A THORN COCKS- 
COMB GALL 
