March 1S94.; 



PSYCHE. 



53 



WING-LENGTH IN SOME NEW ENGLAND ACRIDIDAE.— II. 



BY ALBERT P. MORSE, \VELLESLE\-, MASS. 



Turning to another subfamily, the 

 Acridinae, we tind a genus — JMelatio- 

 plus — in wliicli the wing-length is 

 perhaps as good a character as exists 

 for separating the females of certain New 

 England species; c. g:, j\/. colUniis 

 from jSI. ycmur-rubriim, M. rectus'* 

 from j\l. tninor. 



Yet here, on the other hand, we 

 meet a species, iM. jioiius Dodge, 

 presenting great variation in this partic- 

 ular. Some of the females possess 

 wings and tegmina extending but two- 

 thirds down the femora : others show 

 them passing the end of the femur by 

 nearly a fourth of its length. In the 

 males thev are somewhat less variable, 

 and longer proportionally. It is to be 

 noted, in connection with the brevity of 

 wings in many specimens, that this 

 species is of a sluggish disposition and 

 progresses largely by leaping. 



It is also interesting to observe, in the 

 cases of two abortive-winged species 

 of this subfamily — Melanoplus rectus 



* From an examination of the limited material (con. 

 sisting mainly of the types) in the collections of Mr. 

 Scudder and the Museum of Comparative Zoology and 

 the comparison with these of a relatively large series of 

 specimens taken in Mass., together with a few from 

 Speckled Mt., Me., I see no reason to think that 

 Jilelanoplits rectus Scudd. is other than Pezoteilix 

 horealis Scudd. I use the latter name here for 

 convenience. Mr. Scudder has himself stated the prob- 

 ability that P. borealis is P. septetitrionalis Sauss. I 

 would suggest in this connection that Melanoplus curtus 

 Scudd., from 5000 ft. elevation, Colorado, is likely to 

 prove the same species as M. rectus. 



(= Pez. borealis) and Pezotetti.\ mauca 

 — how the lack of available flight-organs 

 is compensated by tlie alertness of the 

 insects, an extremely swift movement of 

 the hand being necessary to etlect their 

 capture. 



Sharply marked olf from the other 

 members of the family by characters of 

 much interest here are the little "grouse 

 locusts" — Tettiginae In these the 

 wing-covers are reduced to minute 

 proportions, while the dorsal part of 

 the pronotum has been correspondingly 

 developed to supply their place as a 

 covering and protection for the delicate 

 wings. The efficienc)- of the wings as 

 flight organs in those forms in which 

 they are fully developed is unimpaired 

 by the brevity of the tegmina for the 

 reason that the costal border of the 

 wings has become considerably chitin- 

 ized ; when closed this portion also 

 aflbrds some protection on the sides 

 below the pionotal process. 



Here, then, is an opportunity to 

 observe if in the case of variation in 

 length of wings there be a corresponding 

 variation not in length of wing-covers, 

 which are here functionless as such, but 

 in the length of that structure which 

 serves the purpose of tegmina — the dor- 

 sal part of the pronotum. 



Among the eight forms occurring in 

 New England there are three cases in 

 which two are separated merely on this 



