Insect Galls. 49 



CAMPANULALES. 



CICHORIACEAE. 

 Lactuca canadensis. 

 Aulax tumidus Bassett. Lettuce tumor-gall. 



Aulax tumidus Bassett, Trans. Arner. ent. soc, 1890, v. 17. p. -i-i. 



Beutenmiiller, Bull. Amer, mus. nat. hist., 1892, \ . I. p. itv.i. 

 Jarvis, 37th ann. rept. Ent. soc. Ontario, 1906, p. 72. 



This gall consists of an irregular, rough, knotty enlargement of the main 



stem. Sometimes 5-7 cm. long, 2-."> cm. thick, sometimes smaller. Poly- 



thalamous. Common on wild lettuce, Lactuca canadensis. 



AMBROSIACEAE. 



Ambrosia artemisiaefolia. 



Undetermined lepidopterous gall. 



A spindle-shaped woody gall on the main stem or side shoots, below 

 the raceme. Same color as the stem. 15-20 mm. long, 5-7 mm. wide. 

 Monothalamous, cell-walls about 2 mm. thick, rough within. v\n opening 

 near the top provided for emergence. Lepidopterous larva, full-grown in 

 late September. Not rare on rag-weed, Ambrosia artemisiaefolia. 



COMPOSITAE. 

 Eupatorium perfoliatum. 

 Neolasioptera perfoliata Felt. Boneset stem-gall. Fig. 99. 



Choristoneura perfoliata Felt, 22d rept. ins. N. Y. f. 1906, 1907, p. 156-157. 



•Jiii-vis, 38th ann. rept. Ent. soc. Ontario, 1907, p. 88, pi. A, tiK- 5. 

 Veolasioptera perfoliata Felt, 23d rept. ins. X. Y. f. 1907, 1908, p. 319, 332. 



A monothalamous, elliptical swelling of the stem, varying much in size, 

 usually twice the diameter of the stem. Walls about natural thickness. 

 Cavity contains a brown cellular mass. Late summer, common. On 

 thoroughwort, Eupatorium perfoliatum. 



Eupatorium ageratoides. 

 Ceridomyia? eupatoriflorae Beutenmiiller! Fig. 100. 



Cecidomyiat eupatoriflorae Beutenmiiller, Bull. Amer. mns. nat. hist.. 1907, v. 23, p. 391, pi. 16, 

 fig. 4-5. 



An irregularly spherical gall, sometimes indented at the top. A de- 

 formation of a flower-head, some portions of which are to be seen. Fleshy, 

 downy, green. Diameter 1-2 cm. Singly or in groups on white snake- 

 root, Eupatorium ageratoides. September. Springfield, ."Mass. and 

 Suffield, Conn. 



Solidago. 

 Cecidomyia? bifolia, n. s. 



A small, monothalamous gall, binding together two leaves. Hounded, 

 showing a little more above. The leaves grow together. The insect 

 emerges in early summer. Not common. On goldenrod Solidago. 



