REPORT OF THE STATE ENTOMOLOGIST I9I4 



257 



Rhopalomyia thompsoni Felt 



1907 Felt, E. P. N. Y. State Mus. Bui. no, p. 159 



1908 • N. Y. State Mus. Bui. 124, p. 365, 366 



1909 Ottawa Nat., 22: 249 



This species was collected and reared by the late Dr M. T. Thomp- 

 son of Clark University, Worcester, Mass., from a globular or ovoid, 

 fleshy gall on the root stock of Solidago, probably S. j u n c e a. 



Gall. The galls (plate ii, figure 2) have been described by 

 Doctor Thompson as solitary or clustered, ovoid, fleshy, the flesh 

 very spongy and easily torn with the fingers. The larval cells are 

 thin with a scarcely perceptible wall vertically and one to eight occur 

 in a gall. The growth of the plant Ufts the gall above the surface 

 of the ground, at which time its skin bursts and it becomes foliated. 



Male. Length 2.5 mm. Antennae nearly as long as the body, 

 sparsely haired, pale yellowish, the basal ones reddish, the distal 

 segments tinged with reddish; 19 segments, the fifth with a stem 



Fig. 70 Rhopalomyia thompsoni; fifth antennal segment of male 

 and palpus, enlarged (original) 



three-fourths the length of the basal enlargement, which latter has 

 a length one-fourth greater than its diameter; terminal segment 

 variable, usually narrowly oval. Palpi; the first segment rather 

 indistinct, subquadrate, the second long, tapering, slightly curved. 

 Mesonottim dark reddish, submedian Hnes sparsely clothed with 

 fine setae. Scutellum pale salmon, postscutellum dark brown. 

 Abdomen a deep brick red with heavy bands of black scales, genitaha 

 fuscous. Wings hyaUne, costa reddish brown. Halteres yellowish 

 transparent. Legs mostly black, the coxae and base of femora a 

 variable yellowish; claws long, strongly curved, the pulvilli longer 

 than the claws. Genitalia; basal clasp segment long, stout, with a 



