ADAPTATIONS TO HAUNTS AND SEASONS 273 



insects " (Plate I, A) of the tropics, while the Oriental " leaf- 

 insects " have the wings as well as the flattened legs and 

 abdomen shaped, marked, and coloured so as to resemble 

 closely green or withered leaves. The wing patterns of 

 many moths and butterflies are apparently of a nature to 

 afford them protection by concealment when at rest on such 

 objects as tree-bark, reeds, flower-heads, or lichens. The 

 wonderful harmony of the upper forewing surface of the 

 common moth Agriopis aprilina with the greenish-grey 

 lichens on the tree-trunks where it habitually rests has often 

 been given as a perfect example of this particular type of 

 adaptation to haunts shown by many insects. It is well 

 known that most moths rest with the upper surface of the 

 fore wings in full view concealing the hindwings beneath, 

 and that in many groups while the forewings are mottled 

 brown or grey, these hindwings are brilliantly coloured — 

 red or blue in Catocala, yellow in Triphaena. A similar 

 adaptation in resting posture for concealment is shown by 

 many of the grasshoppers and locusts of southern Europe 

 and the tropics, the bright red or blue hindwings being 

 folded and hidden beneath the inconspicuous brown or 

 grey forewings. 



When considering the manner in which insects are fitted 

 to the places where they live it is of especial interest to turn 

 to those that spend all or most of their time in water, because 

 insects are essentially aerial creatures, with their air- tube 

 systems for breathing strikingly adapted to the open 

 atmosphere, as we saw in an early physiological discussion in 

 this book (pp. 40-42), and yet we find among them, whether 

 in the adult or larval stages of many families and orders, the 

 most varied and beautiful modifications for aquatic life. 

 In the course of the racial history of insects, water seems to 

 have attracted them again and again from the early days of 

 their presence on the earth. 



The well-known book by L. C. Miall (1895) on Aquatic 

 Insects serves as an excellent guide to a fascinating line of 

 study for British workers at natural history. Many aquatic 

 insects spend nearly all their lives in ponds and streams 



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