238 ROMANCE OF THE INSECT WORLD CHAP. 



has dimorphic pupae, found that the latter are equally 

 non-susceptible to the influence of adjacent colours. 

 The caterpillars of some of the Mocha Moths 

 (Ephyrida) are also of two varieties, and the pupae 

 developing therefrom appear in two colours, answering 

 to those of the larvae from which they sprang. These 

 pupae, which differ from the pupae of many moths in 

 being freely exposed, are likewise insensitive to the 

 tints of their environment. 



Proceeding now to Variable Protective Resemblance 

 in larvae, the larva of Ciiciillia tanaceti is white when 

 it is feeding on the leaves of the mugwort or tansy, 

 but changes to yellow when it is confined to the 

 flowers of the latter. Long ago Fabricius observed 

 that the larva of Bryophila alg<z varied in colour 

 according to the nature of its food -plant, being yellow 

 when found on Lichen juniperinus, and gray when on 

 Lichen saxatilis. The larva of Cleora lichenaria is 

 wonderfully adapted to the lichen on which it feeds, 

 and differs in shade of colour as it occurs on a light- 

 er dark-coloured plant. Another example of similar 

 variation is afforded by the caterpillar of the Eyed 

 Hawk Moth (Smerinthus ocellatus], which is whitish 

 gray when feeding upon certain kinds of willow, and 

 of a bright yellow green when on other species of 

 willow. The fact that the colour of the caterpillars 

 of certain species may differ according to the colour 

 of the plant on which they occur, is especially notice- 

 able in caterpillars living upon the petals of flowers, 

 or other parts of brilliant hue. This variability has 

 long been known, and it was most natural to suppose 

 it due to the direct action of the chlorophyll or 



