MORSE: ORTHOPTERA OF NEW ENTILAXD. 245 
Arphia, Dissosteira, Scirieticn, Spharogeynon, Pardalophora, iind 
Circotettix. What is the function, tho sifrnificanco of tlioso colors, 
in these hidden phices, seen only in flight or Avhen especially 
displayed? Let us consider the color of the wings first. 
Some authors have explained the presence of striking colors 
and patterns on the wings of Orthoptera, which are concealed 
when at rest, as due to what they term 'contrast-mimicry' and 
primarily of value as a means of dazzling or confusing a pursuer 
by their suililen appearance and disappearance during flight and 
at its termination. In North American species at least these 
colors are usually exposed continuously during flight, though 
disappearing abruptly at its clo.se. However, such an explana- 
tion is a needless tax upon the imagination. There is a much 
simpler one which is almost forced upon the mind of the stroller 
in the fields, and which may be readily observed by taking a 
favorable position in a station thickly populated with adult 
Trimerotropis, Arphia, Spharagemon, and other similarly orna- 
mented Oedipodinae. 
The flight of one of these Locusts attracts attention not alone 
by its display of color but by its crackling character; the con- 
spicuous wing colors, red, yellow, or black, often in strong con- 
trast, render its flight easy to follow, as it is very frequently 
followed, by others, which drop to the ground in close proximity 
to it. There can be no doubt in the mind of one who has watched 
these actions repeated over and over again, of the value of these 
colors as a means of signaling, of attracting attention, and thereby 
effecting or maintaining communication between the sexes or the 
individuals of a community. These wing colors are also fre- 
quently displayed during courtship, while the insect is at rest 
upon the ground or a suitable perch, and even when attacked by 
enemies, as I have observed in some instances. 
The colors of the hind tibiae and inner sides of the hind femora, 
though often bright, are too limited in extent of surface to be of 
use as a signal during flight. They are entirely hidden when the 
insect is at rest, but come into view while it is walking and during 
the stridulator}^ movements of the hind legs which most Acrididae 
practice in mating-time. These conspicuous non-sympathetic 
colors and markings, displayed only at such times, seem to possess, 
therefore, a special significance in relation to this period in the 
