78 



FAMILY II. BLATTID.E. THE COCKROACHES. 



the sexes of Parcoblatta pennsylvanica , and also concluded as the 

 result of extended field work and comparisons, "that the species 

 of PTiyllodromia and Temnopteryx listed 18 by Scudder in his Cata- 

 logue (1900, 8) are but the females of certain species of Isclmop- 

 tera" and they were first so placed, though not always correctly 

 as to species, in my "Orthoptera of Indiana.' 1 



Rehii & Hebard (1010), in studj'ing all their known species 

 of North American IscJinoptcra (Parcoblatta) , followed up this 

 problem of sex correlation, and when through stated that "every 

 species of the genus knoAvn from within our limits has the sexes 

 correlated, with the result that Tcnnio/tfcri/.r and Loboptera (with 

 the exception of one species) are eliminated from our fauna." 

 They failed, however, to properly place the sexes of several spe- 

 cies, and thus left the group still very much confused. 



Hebard has shown that the males of each species of Parco~bl<itt<i 

 have one or more of the dorsal abdominal segments modified or 

 "specialized" in a different way, and has used this as the prin- 

 cipal character in separating that sex. Since the removal or 

 spreading of both tegmma and wings is necessary to see this 

 character, and since the specialization is more or less microscopic 

 in nature, an attempt has been made in this work to separate the 

 males by more obvious characters, but the modification of the seg- 

 ments for each species is mentioned either in the key or in the 

 descriptions. 



Fig. 37. Showing specialization of median and first dorsal abdominal segments of the 

 males of Parcoblatta. A, of P. iililcriana Sauss.; B, P. zebra Heb. ; C, P. virginica (Brunn.) ; 

 D, P. lata (Brunn.); E, P. diz'isa (Sauss.); F, P. pennsylvanica (DeG.). (After Hebard.) 



KEY TO EASTERN SPECIES OP PARCOBLATTA. 



a. Female with inner wings absent and tegmina represented by very 

 small oblong pads, separated by more than twice their width (Fig. 

 39, A.); male with dorsal segments of abdomen unmodified; head 



18 He did not, for some reason, list Temnopteryx deropeltiformis. 



