January iSq;.] 



PSl'CHE. 



red, vellovv tints predominating. It is in 

 no sense protective and bears no rela- 

 tion to the environment, but is probalily 

 of value in the mating of the sexes. It 

 may vary much in the same species, 

 but the sexes are similar. This varia- 

 tion is partly due, no doubt, to age ; for 

 newly matured individuals of a yellow 

 winged species have the disk verv pale, 

 even dull white in color. In some 

 species (e. g., Psinidia fenestral/s) 

 individuals show all shades of color 

 from dull white through yellow and 

 orange to vermilion red. This varia- 

 tion may be found in the same locality 

 or the orange and red examples may be 

 lacking. In Hipfisciis tuberculatus^ 

 whose wings are normally red, yellow- 

 winged examples are very rare. 



Prof. Bruner has sought to connect 

 this diflerence of wing-color with the 

 relative humidity of different localities, 

 stating that the red coloration seemed 

 to be most prevalent in moist regions 

 (Science, 1893, p. 133). This, how- 

 ever, has been questioned (ibid., p. 

 245). In New England I have found 

 red-winged examples oi Ps. fenestralis 

 most common in the warmest parts of 

 the district and suspect that the greatei- 

 intensity of coloration is due in part to 

 higher temperature. This is appar- 

 ently true also oi Arfhia xanthoplera 

 which is entirely yellow-winged here 

 but in the Central States is frequently 

 orange-winged. The yellow-winged 

 examples of H. tuberculatus above re- 

 ferred to are probably to be regarded as 

 cases of reversion, most species of the 

 genus being yellow-winged. 



The Oedipodinae are noticeable not 



onlv from their size and gaih' colored 

 wings but quite as much from the rat- 

 tling noise which the males of many 

 species produce in flight. The female 

 also, in some cases, makes it in less 

 degree. .Stridulation is produced not 

 onlv at this time, however, but also 

 when at rest, as in the Tiyxalinae, by 

 rubbing the hind thighs against the 

 wing-covers, the intercalary vein of 

 which is in most cases toothed or 

 roughenetl. This subject I have treated 

 more fullv in a recent paper (Journ. 

 X. Y. ent. soc, iv, 16-20, Mar. 1896). 



Owing, doubtless, to the conspicuous 

 character of the locusts of this group 

 the majority of our species were first 

 described at an early date from material 

 received from this country by European 

 entomologists. Consequently I have 

 been unable to examine the types, and 

 have used the current names (based 

 upon Scudder's determinations) except 

 in the genus Spharagemon, in which I 

 have followed my recent Revision 

 (Psyche, 1895, Oct.). 



The work& cited under bibliogiaphv, 

 unless otherwise noted, are the same as 

 in Parts I and II* with the addition of 

 Saiissure's Prodromus. 



Owing to their alertness most of the 

 locusts of this group can be secured 

 onl}- by marking down (/. e., taking 

 note of the exact spot where thev 

 alight), approaching carefully, and 

 capturing them by a rapid sweep of the 

 net while thev are on the ground or 



» These are in brief • Beutenmiiller.— Orth. N. V. ; Coin- 

 stock,— Introd. ; Fernald,— Orth. N. E. ; Morse,— List ; 

 Scudder, — Materials ; Smith, — Orth. Me., Orth. Conn. ; 

 Thomas, — Synop. Acrid. N. A. 



