286 ORTHOPTERA OF NOVA SCOTIA. — PIERS. 



the hind margin broadly rounded but never acute-angled, 



median carina low and subequal, the lateral carinse usually 



rounded or obsolete; wing-covers usually well developed. 



This large subfamily may be readily distinguished by the 



presence of the distinct prosternal spine. — In this subfamily 



are found our most injurious orthopterans, and it is therefore 



of the greatest interest to agriculturalists. Oviposition takes 



place in autumn, and winter is passed in the egg stage from 



which the nymphs emerge in early summer, and July finds 



the voracious adults abroad until the end of October sees 



the last of the pests. The amount of damage caused by 



them is very considerable, and some species deserve to be 



closely watched, for in favourable seasons they are liable 



to occur in unexpected swarms. The damage done to Sable 



Island by Melanoplus atlanis a few years ago, is an example 



which we should keep well in mind, of what devastation 



these' insects can do when they appear in prodigious numbers. 



The members of this subfamily rarely stridulate, and then 



only when at rest, by rubbing the serrated lower inner surface 



of the hind femora against veins on the outer surface of the 



wing-covers. There is considerable local variation of colour 



in the species. 



Group Melanopli.* 



Key to Nova Scotian Genera of Locustin^. 



a. Wing-covers wanting; interval between mesosternal lobes (those between 



second or middle pair of legs) distinctly broader than long, as broad or 



nearly as broad as the lobes themselves ; prosternal spine short and conical. 



(Only of hypothetical occurrence in Nova Scotia) . . .[Podisma, p. 286.] 



aa. Wing-covers present, usually well developed but sometimes short, but 

 never wholly wanting; interval between mesosternal lobes longer than 

 broad (not distinctly transverse) Melanoplus, p. 288. 



14. [Podisma glacialis (Scudder). Hypothetical occurrence.] 



Description. — Form of head and body about as in Melanoplus. Face 

 slightly oblique; prosternal spine short and truncate; pronotum faintly 

 constricted in middle in male, and with feebly impressed transverse sulci, 

 its hind margin sub-truncate with a broad but very feeble emargination; 



•For an exhaustive account of this group, see S. H. Soudder's Revision of the Orthopteran 

 Group Melanopli (Acridiida) with special reference to North America, Proc. U.S. Nar. Mus., 

 vol. 20, Wash., 1898, pp. 1-421, pis. 1-25. The species in the present paper are arranged 

 »co rding to this reviaion. 



