38 PROCEEDINGS OF THE NATIONAL MUSEUM vol. no 



Melanoplus bilituratus defectus Scudder, new combination 



Figures 2,i,l; S,d,h; 6; 7,c,e; 8,i; 10,h,j,u; 16,&; Plates 2,a,b,c; 4,a. 



Melanoplus defectus Scudder, Proc. Amer. Philos. Soc, vol. 36 (154), pp. 20, 32, 

 1897; Proc. U. S. Nat. Museum, vol. 20, pp. 132, 177-178, pi. 12, fig. 6, 

 1897. (One male, one female. Grand Junction, Mesa Co., Colo.) Lectotype, 

 designated by Rehn and Hebard (1912, p. 80): Male from Grand Junction, 

 Colo. (ANSP). 



Hebard (1929, p. 390) placed defectus as a synonym of bruneri, 

 but the aedeagus of the lectotype shows that it belongs to the Grand 

 Junction population of bilituratus, here considered to be encompassed 

 within the limits of the southwestern subspecies. The lectotype is 

 small, with a body length of 19.5 mm. The tegmina fail by about 

 2 mm. to reach the tips of the hind femora. The dorsal valve of 

 the aedeagus is poorly sclerotized and pale, but is comparable in 

 shape to other specimens of this subspecies from southwestern Colo- 

 rado. The optimum development of bilituratus defectus occurs in 

 the central and southern portions of Arizona and New Mexico, and 

 it is imfortunate that the type locality is not within that area. The 

 lectotype shows closer relationship to the optimum development of 

 bilituratus defectus than it does to bilituratus bilituratus. The term 

 "intermediate" as used for this subspecies (including the explanation 

 of fig. 6), connotes specimens showing intergradation between the 

 optimum population of bilituratus defectus and bilituratus bilituratus. 

 From a nomenclatural point of view those specimens are not inter- 

 mediates comparable to those discussed elsewhere in this paper 

 because the type locality of bilituratus defectus is outside the area of 

 optimum development. 



The most distinctive character of bilituratus defectus is the dorsal 

 valve of the aedeagus, which in specimens of optimum development 

 has the anterior margin (x of fig. 2>,d) concave and the lateral flap- 

 like area (y) wide and with a sinuate margin (z). In some speci- 

 mens, mainly those intermediate with bilituratus bilituratus (fig. 3,/), 

 the lateral portion is not typically developed. (Also see second 

 paragraph below.) The male cercus usually is about as in figure 

 7,e-2), though occasionally it is much broader (fig. 7,e-3). Especially 

 in intermediate specimens from Baker, Nev., the cercus is narrower. 



Variation : The size of 13 representative males, measured in milli- 

 meters, varies in pronotal length from 3.5 to 5.7 (av. 4.3), in length 

 of hind femur from 9.8 to 14.5 (av. 12.4), and for length of tegmen 

 from 11.5 to 22.5 (av. 17.8). Eight measured females vary in pro- 

 notal length from 4.5 to 6.0 (av. 5.4), for length of hmd femur from 

 13.0 to 16.0 (av. 14.5), and for length of tegmen from 17.5 to 23.4 

 (av. 21.0). Specimens from Ft. Wingate, N. Mex., and Kaibab, 



