Sept., I9I3-] Felt: Descriptions of Gall Midges. 213 



DESCRIPTIONS OF GALL MIDGES (DIPTERA). 



By E. p. Felt, 



Albany, N. Y. 



Below we give descriptions of several species of gall midges, all 

 reared, one striking form representing a new genus and species, while 

 the obtaining of adults enables us to make a positive generic reference 

 for a gall which had been known for several years. 



Winnertzia aceris new species. 



The white larvae of this midge occurred singly or in small groups 

 under thin decaying bark of a sugar maple at Nassau, N. Y., March 

 12, 1913, and presented a somewhat' superficial resemblance to a sparse 

 Miastor colony, except that no mother larvae were to be seen. The 

 adults, closely allied to both W. calcieqiiina Felt and ]V. pcctinata 

 Felt, appeared in April. The male of the former has heavy circumfili 

 extending to the basal fourth of the enlargement, while in this new 

 species the basal portion of the circumfili reaches only to the distal 

 third of the enlargement as in IV. pcctinata. The chitinization of 

 these structures is much weaker than in the last-named species, the 

 basal enlargement is more globose than cylindric, and there are also 

 differences in the genitalia. The stem of the penultimate antennal 

 segment in IV. calcieqnina is greatly reduced, making the 14th segment 

 nearly sessile, a condition not obtaining in this species. 



Larva. — Length 3 to 5 mm., white, the head slender, tapering, light brown.. 

 Antennae large, biarticulate, the distal segment somewhat expanded ; breastbone 

 slender, dark brown, the anterior extremity paler, broadly rounded and some- 

 what expanded. This structure appears to be obsolescent in some specimens. 

 Body segments moderately distinct, the skin finely lined longitudinally and 

 with transverse bands of spines similar to those of Miastor at the incisures ; 

 terminal segment with submedian lobes, each with a slender, curved, chitinous 

 process apically. 



Male. — Length 2 mm. Antennae nearly as long as the body, sparsely 

 haired, dark brown; 14 segments, the fifth with a stem |4 the length of the 

 subglobose basal enlargement, which latter has a length yi greater than its 

 diameter; circumfili extending only to the distal third of the enlargement; 

 penultimate segment with a well developed stem ; terminal segment produced, 

 with a length nearly three times the diameter, tapering to a narrowly rounded 



