THE CANADIAN ENTOMOLOGIST 8!) 



NOTES ON THE NORTH AMERICAN SPECIES OF CORIZUS. 



(COREID/I^., HETEROPTERA). 



BY EDMUND H. GIBSON, U. S. BUREAU OF ENTOMOLOGY, WASHINGTON, D.C. 



After several months of studying long series of specimens representing each 

 species that occurs in North America and many exotic species the author comes 

 to the conclusion that no satisfactory results, as to the limits of each species, 

 the systematic arrangement and relation of species, can be obtained from the 

 mere examination of dried adult specimens, especially without an increased 

 biological knowledge of the group. The writer, therefore, is forced to call 

 tentative any remarks or deductions herein set forth until they are verified by 

 results obtained from life-history and habit studies of each species. At the 

 outset of the study it was the plan to revise the genus, but being forced to abandon 

 this because of the above stated reasons, this paper resolves itself into more 

 or less of a review of Hambleton's* treatise of the North American species, 

 which has been the most notable contribution to our knowledge of the group. 



In the first place attention must be called to the "great similarity of this 

 genus to the Lygaeid genus Nysitis Dall., which has often been a stumbling 

 block for young students and general collectors. In the mind of the author 

 Corizus represents a much degraded -group of Lygseidae and should be considered 

 in that family rather than the nucleus of a subfamily of Coreidse, or else it is the 

 group that links Coreidae with Lygaeidse and is sufficiently different from both 

 to be considered the basis of a separate family (Corizidae L. & S.) The chief 

 point of difference between Corizus and Nysiiis lies in the character and form 

 of the genitalia of both sexes. Also Corizus may be distinguished from Nysius 

 by the lack of a prominent osteolar canal and simplified odoriferous orifice and 

 in the much more produced scutellum. 



From all evidence at hand I agree with several other hemipterologists that 

 subgenera should not be recognized and hence the names Liorhyrsus Stal., 

 Stictopleurus Stal., and Niesthrea Spin, go into synonymy with Corizus. 



The following artificial key is offered as an aid to the identification of the 

 species with the hope that numerous dubious points in Hambleton's key will be 

 cleared up. 



Key TO THE Species. 



1. Antenniferous tubercles very long, approximating the length of the first 



antennal segment tuberculatus Hambl. 



Antenniferous tubercles more or less prominent, but not long or approxi- 

 mating the length of the first antennal segment 2 



2. Posterior border of metapleura not prominently expanded laterally, lateral 



posterior angles broadlv rounding and receding from margin of abdo- 



3 



men 



Posterior border of metapleura more or less expanded laterally, lateral 

 posterior angles usually acute, sometimes rounding but never receding 

 from margin of abdomen * 



3. Species large, connexivum spotted crassicornis Linn. 



Species small, connexivum unspotted viridicatus Uhl. 



*The Genus Corizus with a review of the North and Middle American Species. J. C. 

 Hambleton, Annals Ent. Soc. Am., VoL 1, No. 1, pp. 133-L52, 19U» 

 April, 1919 



