1082 



WALTER H. WELLHOUSE 



White larvae, 3.5 millimeters 

 long and with a distinct 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 -v^MM^UA 

 of the leaves of Crataegus FlG 117 CROSS SECTION THR OUGH A THORN COCKS- 

 punctata. The gall opens by COMB GALL 



FlG. 116. THORN COCKSCOMB GALL 



