158 



NEW YORK STATE MUSEUM 



arise. The larvae winter in the enlarged central cavity. This gall 

 is somewhat common on Staten Island and 

 occurs sparingly at West Nyack, N. Y. Appar- 

 ently the same gall was also observed at Nas- 

 sau, N. Y., it occurring in this latter instance 

 on Solidago graminifolia. Pre- 

 sumably the same species was taken by Mr 

 J. R. Gillett on Mt Tom, Mass., July 22, 1906. 

 A species of Polygnotus was reared from this 

 midge. 



Gall. A uniform enlargement of the upper 

 portion of Solidago stems. Length 10 cm, 

 diameter .7 cm, the central cavity slightly 

 enlarged and inhabited by a number of pale 

 yellowish larvae. 



Larva. . Length 3.5 mm, rather stout, pale 

 orange. Head small, antennae slender; breast- 

 bone slender, distinctly expanded apically, tri- 

 dentate, the median tooth rather small; skin 

 coarsely shagreened ; ' posterior extremity 

 broadly rounded. 



Male. Length 2 mm. Antennae dark 

 brown, basally silvery white, 15 or 16 segments, 

 the fifth with a length slightly greater than its 

 diameter; terminal segment slightly produced, 

 tapering to an obtusely rounded apex. Palpi 

 fuscous yellowish, the first segment subquad- 

 rate, slightly swollen distally, the second about 

 as long, irregular, the third one-half longer 

 than the second, more slender, the fourth one- 

 half longer than the third, more slender; face 

 with a patch of silvery white. Mesonotum 

 dark brown, variably margined laterally and 

 anteriorly with silvery white and yellowish 

 scales, the submedian lines rather sparsely 

 clothed with golden yellow hairs, the median 

 and sublateral areas rather uniformly clothed 

 with short, golden yellow hairs. Scutellum dark 

 brown with numerous yellowish setae apically, 

 postscutellum dark brown. Abdomen dark 

 brown with large, submedian rows of lunate, 

 silvery white spots, the latter on the posterior 

 margins of the segments and extending to the 

 lateral line; genitalia dull yellowish, slightly 

 fuscous apically; venter suffused with silvery 

 white scales. Wings hyaline, costa dark brown, 

 discal spot yellowish, the third vein yellow- 

 ish, uniting with costa near^the distal third. Halteres a nearly 



f 



Fig. 27 Lasiop- 

 tera cylindri- 

 g a 1 1 a e , swollen 

 stem, A, portion 

 in section, enlarged 

 (original) 



