368 



FAMILY VI. ACRIDID^E. THE LOCUSTS. 



than prouotum, their inner margins not overlapping, the dorsal 

 and anal fields not defined, tips broadly rounded ; hind femora 

 slender, equalling or feebly surpassing tip of abdomen, male, 

 reaching base of ovipositor, female, their color nearly uniform, 

 without dark cross-bars ; extremity of male abdomen but little en- 

 larged, feebly upcurved; furcula and cerci variable according to 



a. 



aa. 



Fig. 127. Outlines of cerci of males of Melanoplus. ><^ 16. a, decants; b, australis', 

 c, attenuatus; d, hebardi; e, nubiltts; f, deccptus; g, similis. The last two synonyms of 

 viridipcs. (After R. & H. and Morse.) 



species; subgeuital plate distinctly tapering from base to apex, 

 the latter narrow, rarely tuberculate, but usually with a subapical 

 tubercle. Five closely related forms comprise the group, all rep- 

 resented in the southern coastwise states and hygrophilous in 

 habitat. 



KEY TO EASTERN SPECIES OF DECORUS GROUP. 



Postocular dark-stripe present but narrowed on metazona; middle of 

 apical margin of subgenital plate of male projected upward as a 

 distinct and slender tubercle; furcula one-third or more the length 

 of supra-anal plate (Fig. 128, a.) 161. DECORUS. 



Postocular dark stripe ending abruptly at front margin of metazona; 

 apical margin of subgenital plate without a tubercle, the plate usu- 

 ally with a blunt one below the margin. 



b. Sides of abdomen without black markings; apical third of male 

 cerci spatulate, the tips broadly rounded (Fig. 127, b.) 



1G2. AI T STRALIS. 



bb. Sides of abdomen with a black stripe or blotches; apical third of 

 cerci but slightly widened, the tips subtruncate, feebly bifid 

 (Fig. 127, c, d, e.) 



c. Larger, length of body, male, 18.5 22 ; dorsal surface of ab- 

 domen pale. 



(/. Prozona one-half longer than metazona; basal third of lateral 

 margins of supra-anal plate incised to form a prominent 

 broadly rounded overlapping fold; furcula slender, evenly 

 tapering, about one-fourth as long as supra-anal plate 



(Fig. 128, C.) 163. ATTENUATUS. 



dd. Prozona nearly twice as long as metazona; basal marginal 

 plications of supra-anal plate evident but feeble; furcula 

 small knob-like plates with divergent angulate tips, 

 scarcely one-fifth the length of supra-anal plate. (Fig. 

 128, d.) 163a. HEBARDI. 



