226 



A Revision of the Genus Johannsenielea for 

 North America 



This genus belongs to the subfamily Ccratopogonincc and is dis- 

 tinguished from the other genera in this subfamily by the following 

 characters : Wings bare ; a cross vein connecting the first and third 

 veins as in Palpoinyia; legs of moderate strength, neither the fore 

 nor hind femora much thickened ; all femora without spines on the 

 ventral surfaces. 



During the progress of my work in determining the CliironomidcE 

 in the collection of the Illinois State Laboratory of Natural History 

 I have had to go to considerable trouble in getting together the 

 scattered descriptions of species belonging to this genus, and to 

 facilitate my work have drawn up a synoptic key which has in large 

 measure proven useful in the work of identification. I make no claim 

 that the key here presented is perfect, or that by means of it all the 

 species of this genus occurring in North America may be identified, 

 since in large part it is drawn from descriptions, and, more particu- 

 larly, because there must be far more species belonging to this genus 

 in North America than are here listed. 



The Illinois species represented in the collection here are described 

 so as to facilitate their identification where they may occur. 



The habits of the species in this genus are very similar to those 

 of Palponiyia, to which J oJiannseniclla is very closely allied, dififer- 

 ing from it only in the absence of the femoral thorns. The tw^o 

 species which have been reared from the pupal stage by members 

 of the staff of this Laboratory are herewith figured in that stage. 



Synopsis of Species (Females) 



1. Wings with distinct spots or bands 2 



— Wings unspotted, at most the cross vein infiiscatcd 4 



2. Wing with 3 spots nehulosa Coquillet. 



— Wing with 2 spots 3 



3. Tibiae entirely black dimidiata Adams. 



— Tibiae black at apices only himacidofa Loew. 



4. Abdomen covered with silvery pollinosity ; mesonotnm glossy 



black argentata Loew. 



— Pollinositv on abdomen indistinct, or if distinct then never silvery 



'. 5 



5. Ci'oss vein of wing very heavily infuscated, the veins on other parts 



of the wing almost colorless alharia Coquillett. 



— Cross vein not noticeably infuscated, and not more distinct than the 



other thick veins 6 



6. Species with the mesonotnm yellow or green 7 



— Species with the mesonotum black or black-brown 9 



