The Pentatomidae of Nebraska 27 



Thyreocoris nitiduloides (Wolflf). 



1802. Cimex nitiduloides Wolff, Ic. Cim., Ill, p. 98, fig. 92. 

 1831. Thyreocoris histeroides Say, Het. Hem., N. Harm., Ind. 



This species is quite generally distributed over Nebraska and I 

 have specimens at hand which were taken at Lincoln, Roca, 

 Nebraska City, Cedar Bluffs, West Point, Neligh, Cherry county, 

 Halsey and " Sand Hills." 



This form and the preceding one approach rather closely to 

 each other but the specimens I have can be separated on the char- 

 acters given in the above key. Unicolor averages larger and more 

 highly polished than nitiduloides, but in nitididoides there is a 

 deeply impressed line arising between the subcostal and cubital 

 nervures at their base and running parallel to the former, leaving 

 a distinct ridge parallel to it which extends the greater part of 

 the length of the corium. This shows more plainly when the 

 insect is viewed directly from above. In unicolor there may be a 

 somewhat raised portion just within the subcostal nervure but it 

 is not bounded inwardly by a distinct, impressed line. Niger 

 more nearly approaches nitiduloides in this regard but in nitidu- 

 loides again there is a finely impressed line just exterior and 

 parallel to the cubital nervure and reaching nearly or quite to- 

 the tip of the corium, making the nervure appear double, while 

 in niger this line is absent, although a broken row of rather coarse 

 punctures may occupy nearly the same position and the suture 

 itself be lost in a punctate groove. These characters may seem 

 trivial, but I have found them less subject to variation than the 

 more commonly used ones of size, form, etc. 



Thyreocoris niger (Dallas). 



1851. Corimelaena nigra Dallas, List, I, p. 57. 



Found only to the north and west. There are six specimens in 

 the collection from Halsey, Crawford, Glen and Monroe canyon. 



This species averages shorter oval than the preceding and shows 

 a rather distinct transverse wrinkling on the pronotum and the 

 base of the scutellum, while in color it is a more opaque black. 

 Other characters are given under nitididoides. 



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