DECEPTIVE COLOURING. 
The Acridiidce more than any other group of insects exhibit that 
combination of colours which is designated under the above term, a 
scheme of colouring designed to deceive birds and other predators which 
pursue these insects. The essential features are a cryptic scheme of 
colouring functional when the insect is at rest, with bright and conspi¬ 
cuous colouring revealed only when the insect is in flight and concealed 
by the forewings or by the attitude when the insect alights. If one goes 
into a grass field, intent on observing large grasshoppers, one will sud¬ 
denly see a brightly coloured insect jump up, fly a little distance and 
disappear. One sees it by the bright colours and one can, as a rule, 
easily follow its flight by them. These bright colours are in the lower 
wing and perhaps part of the abdomen ; they are visible only when the 
forewings are expanded in flight revealing the large expanse of lower 
wing and the abdomen. The insect in flight is easily visible owing to 
these bright colours and the Acridiids fly with a swift jerky motion, at 
the end of the flight suddenly wheeling down and settling motionless 
with closed wings. The eye has followed the bright colours and loses the 
insect as these disappear with the closing of the wings at the completion 
of the flight. One’s eye is not seeking the cryptically coloured grass¬ 
hopper, which thus escapes attention, even if one could easily see the 
motionless insect coloured in shades approximating to its surroundings 
and marked with darker colours to suggest the light and shade in the 
vegetation. With the exception of the warningly coloured grasshoppers 
and the vividly coloured locusts, deceptive colouration of this kind, de¬ 
pending upon bands of yellow, red or other vivid tints, is very common 
among Acridiids. Exceptionally beautiful examples are found in Gas- 
tromargus (Oedaleus) and in the extremely striking Teratodus monticollis , 
the colouring in the latter being on the body under the wings rather 
than on the wings. An instance is also found in the Leaf butterflies 
(Kallima inachis, and K. Horsfieldi) in which the upper surface of the 
wing has a bright orange blotch, visible in flight, whilst the form of the 
wings, the colouration and the resting attitude are extraordinarily like 
a leaf; at rest the insect is invisible, in flight it is conspicuous and the 
transition from the latter to the former at the close of a brief zigzag flight 
is extraordinarily deceptive. 
Another group with conspicuous examples is the Sphingidcc, the 
body and forewing of the large species being commonly coloured in dull 
cryptic tints which harmonize with bark, while the lower wings are 
