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LETTER XIL 

 ON THE FOOD OF INSECTS. 



Insects, like other animals, draw their food from the vegetable 

 and animal kingdoms ; but a very slight survey will suffice 

 to show that they enjoy a range over far more extensive ter- 

 ritories. 



To begin with the vegetable kingdom. — Of this vast field 

 the larger animals are confined to a comparatively small por- 

 tion. Of the thousands of plants which clothe the face of the 

 earth, when w^e have separated the grasses and a trifling 

 number of herbs and shrubs, the rest are disgusting to them, 

 if not absolute poisons. But how infinitely more j^lenteous 

 is the feast to which Flora invites the insect tribes ! From 

 the gigantic hanyan which covers acres Avith its shade, to the 

 tiny fungus scarcely visible to the naked eye, the vegetable 

 creation is one vast banquet at which her insect guests sit 

 down. Perhaps not a single plant exists which does not 

 afford a delicious food to some insect, not excluding even 

 those most nauseous and poisonous to other animals — the 

 acrid euphorbias, and the lurid henbane and nightshade. Nor 

 is it a presumptuous supposition that a considerable pro- 

 portion of these vegetables were created expressly for their 

 entertainment and support. The common nettle is of little 

 use either to mankind or the larger animals ; but you will not 

 doubt its importance to the class of insects, when told that 

 at least thirty distinct species feed upon it ; and however 

 important the oak may be to us, it is still more so to the 

 insect world, of which Rosel calculated that two hundred 

 species either feed upon it, or upon other insects which do. 

 But this is not all. The larger herbivorous animals are con- 

 fined to a foliaceous or farinaceous diet. They can subsist 

 on no other part of a plant than its leaves and seeds, either 

 in a recent or dried state, with the addition sometimes of the 



