INSECTS. 





climb the trunk of the tree. If now we put a girdle of printer's ink. c 

 tar, or oil around the tree, she cannot pass it, and the \ea,\ nseque 



will not be eaten by the larvae. 



Other geometrids affect other plants, and at times do a great amounl 



of damage. To enumerate the species and the plants th, | n is 



beyond our scope; such accounts should be sought in the works on eco- 

 nomic entomology. There is, however, another side of the life of the 

 geometrids to which we may refer. All throueh 

 the line of insects we meet with cases of 'protective I ) 



resemblance,' instances where one form so mimics ^ ^-w 

 other objects as not to be readily distinguished : at 



Fig. 2t>±. — Gooseberry span-worm and moth (Abraxas). 



times one insect will curiously copy another in its 

 shape and color ; again, as we saw in the case of the 

 walking-stick and the walking-leaf, it takes a part 

 of a plant as its copy. Some of the geometrid larvae 

 give us excellent examples of this ; for instance, there fig. 265.— Juuiper-moth 



,.,«.. . . n panodes) and larvae apt 



is a measuring-worm which feeds on the lumper, and juniper-twig, in Life 



,., •ill- c larvae, when "i«>n their 1 



Which, as it hold itself Stiff and rigid for hours at a plant, are even in..re difficult 



. o . to detect than in the cul 



time, would hardly be noticed, so closely does it re- 

 semble one of the twigs which has been divested of its leaves, leaving 

 nothing but the scales behind. There can be no doubt but that in all 

 these cases the resemblance is for the benefit of the animal ; for they are 

 less readily seen, and hence are far more likely to escape the notia 

 insect-eating birds and other predaceous forms. 



The largest family of moths is that known as the Noctuidae, a na 

 given in allusion to their nocturnal habits — habits which, h< 

 shared by the great majority of other moths. When the lamps are ligh 

 on a summer evening, these forms come in large numbers, seemingly in 



