40 



afford food for the larvae of Cleora lichenaria, and the perfect insect 

 would find a safe resting-place thereon because the colours of insect 

 and lichen would blend harmoniously together. 



The great bulk of Lepidoptera conceal themselves during the day 

 among the foliage of trees or bushes, or hide at the roots of grasses 

 and other herbage. In whatever way they may rest, enemies of 

 various kinds are ever on the alert, and wherever the moths may 

 secrete themselves, they would be in danger of detection and seizure 

 unless their structure, ornamentation, and colour either harmonized 

 with their immediate surroundings, or counterfeited some natural 

 object occurring near their resting-places. Possibly you may have 

 met with that ubiquitous insect Triphcena pronuba hiding away under 

 various plants in fields and hedgerows. It is not often seen among 

 the foliage of plants, but generally on the ground and near the root- 

 stock of the plant. In this position it is not unlike a stone, and 

 for such an inanimate object I have frequently mistaken it, until I 

 attempted to touch it, when it darted away and at the same time 

 revealed its identity by exposing its yellow hind wings. Agrotis 

 strigula (porphyrea) and Anarta 7nyrtilli offer excellent examples of 

 protective ornamentation. The colours of the fore wings of each 

 of these insects blend admirably with the colours of the dead twigs 

 and flowers of the heather, upon and among which these species 

 rest. Species of the genus Xanthia agree in a striking manner with 

 the dead and dying leaves of their food plants. Thus we see 

 typical Xanthia fulvago {ccrago) is in coloration exactly like a dying 

 leaf of the sallows Salix aurita and Salix caprcce, even to the spots. 

 The lemon-coloured variety of Xanthia fulvago, known as flavescens, 

 is said to be chiefly bred from larvae found feeding on the leaves 

 or catkins of Salix viminalis, a narrow-leafed species of sallow 

 commonly called "osier." The insect in this case is smaller than 

 the type, and is of the same tint of colour as the dying or defunct 

 leaves of the osier. Oporina croceago is often found during the 

 winter hibernating among the dead leaves of oak as they hang on 

 the young or scrubby oaks growing in hedgerows, etc., on the 

 borders of woods. 



So far, except in the case of Xanthia fulvago, I have confined 

 my remarks to what may be termed typical coloration; I shall 

 now refer more particularly to variations from the type, and shall 

 endeavour to show that such variation is not of the accidental 

 character it is often supposed to be, but is closely connected with, 

 or I should say influenced, by, the nature of the insect's surroundings 

 in different localities. 



