KEY TO AMERICAN INSECT GALLS 



79 



6 Gall a swelling of the midvein or sometimes of the petiole (See also (13) P- 106, and (15) a, b, 



p. no) 



(i) Swellings abrupt 



Globose or spindle-shaped, woody, green petiole or midrib gall on Q. alba, 

 Q. prinus, Q. macrocarpa, Q. bicolor, Q. prinoides, 

 Q. obtixsiloba. Fig. 7^- Bass. '63, p. 324 



Cynipid. Oak leaf stalk gall, Andricus petiolicola Bass. 

 Polythalamous, midvein gall projecting on both surfaces, rounded beneath, 

 conical above, length 19 to 22 mm, diameter 12 mm, on Q. a 1 b a . PI. I, 

 fig. I. Bass. '90, p. 80 



Cynipid. Andricus cicatrical us Bass. 



Irregular, polythalamous, reddish brown, woody thickening of the midvein or 



leaf and containing radiating larval cells, length 8 to 15, mm, diameter 5 to 6 



mm, differs from both Andricus petiolicola and C a 1 1 i r h y t i s 



t u m i f i c a . Mex. Trotter '11, p. 131 



Cynipid. ? C y n i p s sp. 



Fig. 75. Midrib tumor gall, Callirhytistumifica O. S. 

 (Original) 



Fig. 76. Midrib tumor gall, C a 1 1 i - 

 rhytis tumifica O. S. Sec- 

 tion showing arrangement of larval 

 cells. (Original) 



Soft, thin-shelled, red or brown vein galls frequently closely pressed together 

 and somewhat resembling figs, onQ. alba,Q. prinoides and Q. 

 p r u n u s . Fig. 66, 84, 1,2. Beutm. 'ogd, p. 244 



Cynipid. Oak fig gall, Biorhiza forticornis Walsh 



Small, rounded, polythalamous, midvein gall projecting equally on both surfaces, 

 diameter 2 to 3 mm, on Q. p a r v i f o 1 i a . Ashm. '87, p. 138 



Cynipid. Callirhytis parvifoliae Ashm. 



Globose, polythalamous, midvein gall near the base of the leaf, prominent on 

 both surfaces, diameter 6 mm, cells radiating from a common center and not 

 separable from woody fiber about them, on Quercus species. Bassett '90, 



P- 74 



Cynipid. Callirhytis reticulata Bass. 

 Irregular, polythalamous, globose, fleshy gall occurring near the base of the leaf 

 and projecting about equally above and below, diameter 4 to 7 mm. Ashm. 

 '97, p. 116 



Cynipid. Andricus morrisoni Ashm. 



