FOOD OF INSECTS. 



337 



alternative such a state of torpid insensibility as that with 

 which our larva purchased the prolongation of its existence. 



After this general view of the food of insects, and of cir- 

 cumstances connected with it, I proceed to give you an 

 account of some peculiarities in their modes of procuring it. 



The vegetable feeders have, for the most part, but little 

 difficulty in supplying their wants. In the larva state they 

 generally find themselves placed by the parent insect upon 

 the very plant or substance which is to nourish them ; and in 

 their perfect state their wings or feet afford a ready con- 

 veyance to the banquet to which, by an unerring sense, they 

 are directed. All nature lies before them, and it is only 

 when their numbers are extraordinarily increased, or in con- 

 sequence of some unusual destruction of their appropriate 

 aliment, that they perish for want. The description of their 

 food renders unnecessary those artifices to which many of 

 the carnivorous insects are obliged to have recourse ; and 

 none of them, if we except the white ants, whose cunning 

 mode of insinuating themselves into houses in tropical 

 climates has been detailed in a former letter, can be said to 

 use stratagem in obtaining their food. 



Of the carnivorous species, the greater proportion attack 

 their prey by open violence ; such as the predaceous beetles, 

 the Ichneumons, burrowing wasps, and true wasps ; the 

 praying insects (^Mantis)', the bugs (^GeocoriscE Latr.); 

 dragon flies {Libellulina), &c., which have been before ad- 

 verted to. But a very considerable number, chiefly, how- 

 ever, of one tribe, that of spiders, provide their sustenance 

 solely by artifice and stratagem, the singularity of which, and 

 the admirable adaptation of the instruments by which they 

 take their prey to the end in view, aflbrd a most wonderful 

 instance of the power and wisdom of the Creator, and have 

 attracted admiration in all ages. A description of these, 

 however, which will require a detailed survey, I must defer 

 to another letter. 



I am, &c. 



VOL. I. 



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