32 THE ACRIDIIDAE OF MINNESOTA 
and the wings are nearly always, at least in part, brightly colored. 
This group includes all of those species of our fauna in which the basal 
portion of the wings is brightly colored, the colors ranging from 
yellow to red or in some cases even black, while in certain forms found 
outside our area they are even blue. So strongly marked is the colora- 
tion that members of some species are as conspicuous in flight as the 
butterflies. The purpose of this coloration has been of considerable 
interest among students and several theories have been advanced to 
explain its significance. Morse has said that “it is in no sense pro- 
tective” and his suggestion is that the colors are probably “‘of value in 
the mating of the sexes” but this, while possible, is rather vague. 
Without attempting to enter into a full discussion of this subject 
here, we may call attention to the close similarity in the details of the 
common Oedipodine coloration to that of the Catocalae among moths. 
In both cases the body color is of some obscure brown or gray, the 
tegmina similarly obscure, and the wings strongly marked, consisting 
of a brightly colored field broken by one or more dark bars, contrast- 
ing strongly with the field. The coloration is visible, in both cases, 
only when the insect is in flight and the insects are commonly found 
upon a background having more or less close resemblance to the ob- 
scure colors of the body and tegmina. Two ideas present themselves 
as worthy of note, though not necessarily as the only explanations pos- 
sible for the problem. The one is that conspicuous objects, such as 
these insects are when in flight, may become very much less apparent 
when the insect suddenly drops upon a suitable background. The 
strongly contrasting colors being suddenly covered by the obscurely 
colored tegmina causes the insect to “fade away” in bewildering fash- 
ion. We are here considering this coloration, however, solely from 
the view-point of human optics and can not be certain that the effect 
upon the eyes of a pursuing bird would be the same. Another thought 
that has been put forth already by some as a theory explanatory of 
this coloration scheme, is that the brightly colored area of the wing 
being so conspicuous will lead a pursuing bird to strike at this non- 
vital part rather than at the body of the insect. We may here note 
that we have on numerous occasions seen the English sparrow rise and 
strike at specimens of Dissosteira carolina in flight but pass the same 
insect without notice while it fed upon the ground. Further, after 
watching these attempts at capture, we have noted that the bird, in 
this case at least, does attempt to seize the wing. As to the value of 
this coloration in mating, it is noteworthy that the coloration is dimor- 
phic in a number of these species and mating occurs, for instance in 
Hippiscus rugosus, between individuals with the wings red or yellow 
alike. Further, the shades of red or yellow are often identical in dif- 
