January 1S94.] 



PSYCHE. 



13 



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



BY ALBERT P. .MORSE, WELLESLEV, MASS. 



The title ill full of this paper may be 

 stated as "Length of wings as an evi- 

 dence of specific distinctness and its value 

 as a diagnostic character in reference to 

 some New England Acrididae." In 

 using the term length of wing the length 

 of the wing-covers or tegmina is in many 

 instances included. 



It was formerly the custom among 

 writers on this family to base specific 

 distinctness more or less largely on a 

 difierence in the length of wing presented 

 bv some closely allied forms, and to give 

 kevs for the determination of species in 

 which this was used as a diagnostic 

 character.* 



My experience with New England 

 forms has led me to conclude that this 

 character of wing-length as found in 

 some of these is extremely unreliable, 

 and that the description of a new species 

 foimded wholly or largely on this charac- 

 ter should be received with great caution. 



As an instance of specific variability 

 <ni this point let me cite the case of 

 Opomala hrachyptera Scudd. This 

 locust, a well-known and widely-dis- 

 tributed species, possesses ordinarily 



*A still more unsatisfactory practice was that of com- 

 paring the wing-length to the abdomen, tlius : "Tip of 

 wings passing- abdomen." The abdomen of the female 

 locust is so variable in length, owing: to size and num- 

 ber of eggs, and extension due to oviposition, that it 

 seems strange tliat .any one should have used this rela- 

 tion when one of equal practical value not subject to 

 variation exists, viz ; comparison with the hind femora. 



\vlng- covers extending on the hind 

 femora in the male to about one-half the 

 distance to the tip, in the female to 

 about one-fourth or one-third the dis- 

 tance to the tip, the wings in both sexes 

 being nearly or quite aborted. In July, 

 1893, I had the good fortune to capture 

 a female similar in all respects to the 

 ordinary form but having the tegmina 

 extending to the end of the femora and 

 the wings fully developed. Could it 

 be another species.^ Further search 

 soon resulted in the capture of a nor- 

 mal male brachyptera and left little 

 doubt in my mind that here was a case 

 of reversion to the earlier long-winged 

 form of female. Search in another 

 localitv several miles distant resulted in 

 the captme of over fifty specimens 

 among which were four long-winged 

 females and two long-winged males. I 

 have since obtained another long- 

 winged male from a neighboring town 

 and Mr. Scudder has one in liis collec- 

 tion from Iowa. 



Turning to the genus C/iloealiis, — 

 or as it is also known, Chiysoc/iraon, — 

 we find three forms described as occur- 

 ring in New England. In one of these, 

 C. conspcrsa, the female possesses 

 abortive wings and the tegmina rarely 

 reach half-way to end of femora. Both 

 wings and tegmina are somewhat 

 more developed in the male but not 

 enough to serve as organs of flight. I 



