106 NEW YORK STATE MUSEUM 



This somewhat characteristic gall is rather common upon willow, 

 Salix, twigs in the vicinity of Albany, N. Y. and in the neighborhood 

 of New York City. Illinois specimens in the Museum of Com- 

 parative Zoology at Cambridge, Mass., are smaller than those 

 commonly occurring in this State. Apparently the same gall has 

 been received from Prof. T. D. A. Cockerell, Colorado. The 

 adults winter in the gall, appearing in early spring. The wing and 

 genitalia are illustrated on plate 5, figure 4 and plate 7, figure 3 

 respectively. 



The gall is a very irregular, polythalamous enlargement occurring 

 on the shoots of the low swamp willow, Salix h u m i 1 i s . It 

 varies greatly in size and somewhat in form. See plate 9, figure 1. 

 Polygnotus species was reared from this gall. 



Rhabdophaga salicifolia Felt 



1907 Felt, E. P. New Species of Cecidomyiidae II, p. 12-13 

 1008 N. Y. State Mus. Bui. 124, p. 293-94, 355 



This characteristic gall is somewhat common on meadowsweet, 

 Spiraea salicifolia, in the vicinity of Albany, N. Y., and 

 is quite abundant in some sections of eastern Massachusetts. It was 

 taken by Miss Cora H. Clarke in the vicinity of Magnolia, Mass. 

 The midges were reared in July 1907 from galls taken near Albany, 

 N. Y. Tory mus ostensackenii D. T. was also reared 

 from this gall. 



Gall. This is a thickened, greenish fold of the midrib 1 to 1.5 

 cm long and about 6 mm in diameter, plate 4, figure 12. It is in- 

 habited by several pale yellowish larvae. 



Male. Length 1.5 mm. Antennae probably a little longer than 

 the body, dark brown; at least 12 and probably 20 segments, the 

 fifth with a stem about as long as the basal enlargement, which 

 latter has a length nearly twice its diameter. Palpi; first segment 

 short, stout, irregularly subquadrate, the second stout, rounded at 

 the extremity, subrectangular, with a length fully twice the diameter, 

 the third one-half longer and more slender than the second, the 

 fourth a little longer and more slender than the third ; face fuscous. 

 Mesonotum dark brown, the submedian lines sparsely haired. 

 Scutellum a deep reddish brown, postscutellum dark fuscous. Ab- 

 domen dark brown, sparsely clothed with fine hairs. Wings hya- 

 line, costa light brown. Halteres fuscous basally, fuscous yellowish 

 apically. Legs a somewhat variable fuscous yellowish, the femora 

 basally light yellowish ; claws long, slender, strongly curved, the 

 pulvilli a little longer than the claws. Genitalia; basal clasp seg- 

 ment long, stout; terminal clasp segment short, stout; dorsal plate 

 short, broadly and triangularly incised ; ventral plate long, broad, 



