312 



NEW YORK STATE MUSEUM 



Key to genera 



a Antennal segments globose with a smooth stem distally and ornamented 

 only with whorls of long hairs. The 3d vein is well separated from 



costa and unites with the n^argin at or beyond the apex 



Joanissia Kieff. 



aa Antennae variable, frequently with crenulate wliorls and subapically with 



variously formed chitinous structures ; the 3d vein uniting with the 



margin before or near the apex Campylomyza Meig. 



JOANISSIA KiefF. 

 This genus presents a very characteristic invm and is easily sepa- 

 rated from all other Cecidomyiids. The antennae in both sexes are 

 composed of a number of segments, each consisting of a subglobu- 



FiR. 30 Joanissia photophila Felt, sth and loth antennal segments of male ■ 

 much enlarged. (Original) 



lar basal enlargement ornamented only with irregular whorls of 

 simple setae .and a smooth, cylindric stem distally [fig. 30]. The 

 male has 14 and the female 11 antennal segments. The palpi are 

 tri or quadriarticulate. The venation of the wing is very charac- 

 teristic, as the third vein is well separated from costa, runs nearly 

 parallel thereto and unites with the margin at or well beyond the 

 apex ; the fourth vein is simple. 



Nothing is known concerning the life history of our native forms, 

 though Kieff er has recorded the rearing of several European 

 species from decaying wood, from tufts of moss and also from a 

 mold covering a fungus. It is very probable that our American 

 forms live under similar conditions, particularly as they seem most 

 abundant in the vicinity of forests or other conditions where decay- 

 ing vegeta'ble matter is present in some abundance. 



