FIELD BOOK OF INSECTS. 



The orange-colored larva of Cecidomyia 

 pini-rigida lives in a basal enlargement of 

 shortened, deformed needles of pitch pine; and C. balsami- 

 cola, of balsam. Thecodiplosis ananassi makes a brown, 

 pineapple-like gall on cypress. Itonida anthici makes a 

 whitish, flower-shaped, fungus-like growth on cypress. 

 Retinodiplosis resinicola larvae are orange "grubs" living 

 in clear or whitish masses of pitch on the under side of 

 pitch-pine branches; R. inopis, in resinous masses on 

 scrub-pine leaves. 



Pemphigus populicaulis makes globular 

 Poplar and Ug at the bage of Jeaveg (p late XC y 



Cottonwood 



Fig. i); P. popuh-transversus, oval, some- 

 what elongated galls on the petioles; P. populi-veruz, yel- 

 low galls on midrib of leaf; P. vagabundus folds and 

 crinkles the foliage. Agromyza aeniventris causes irregu- 

 lar, somewhat globular enlargements of young twigs. 



More than fifty different galls have been 

 WiUow described. See Plate XCV. 



Twigs 



Phytophaga (also put in Rhabdophaga} rigidtz (Fig. 4); 

 Rhabdophaga batatas (Fig. 3) and strobiloides (Fig. 5). R. 

 strobiliscus is like strobiloides but all the leaves are pointed at 

 the tip. R. rhodoides and others make more open growths, 

 resembling small, double flowers. R. brassicoides: bunches 

 of oval, single-celled, sessile galls, each three-fourths to 

 two and a fourth inches, "like the sprouts of a cabbage 

 stump," usually not near tips of branches. R. triticoides: 

 many-celled and resemble a wheat-head. R. nodulus: 

 like batatas but smaller, more solitary, and only single- 

 celled. For Euura ovum see Fig. 6; E. nodus, a smooth 

 twig enlargement, one-fourth to twice normal diameter; 

 E. orbitalis, enlarged, bud-gall. 



458 



