UTILITY OF INSECTS. 19 



in the instrumentality of a large proportion of iu.sects in their character 

 of scav^engers, whereby the decomposition of de(;ayed and offensive 

 matters, both animal and vegetable, is effected and accelerated ; and 

 thirdly, in the agerjcy of insects ia causing the fertilization of plants, 

 especiially those with very deep corrollas, and those which have the bar- 

 ren and productive flowers upon different plants, by carrying upon their 

 legs, in their search for honey, the fertilizing pollen from one tlower to 

 another. A long chapter might be written upon each of these topics, 

 but we have space here barely to enumerate them. 



DIVISION OF INSECTS ACCORDING TO THE NATURE OF THEIR FOOD. 



From this point of view all insects may be divided into two classes — 

 the carnivorous insects, or those which eat animal food, {Sarcophaga) ; 

 and the herbivorous insects, or those which subsist upon vogetal^lesub- 

 stance.s, ( Phytophaija ) . Each of these cl asses i s agai n d i \' i si bl e accord i n g- 

 ly as the insects which compose it take their food in a fresh and living 

 state, or in a state of de<;ay. The former are called preda<;eous insects 

 {Adephofja), when they live upon animal prey; and the latter are desig- 

 nated by the name of scavengers (Kypophaga). Those insects which eat 

 living animal food, are still further divivsible into predaceous insects 

 proi)er, which seize ami devour their prey, and parasite insects, which 

 live within the bodies of their victims and feed upon their substance. 



Those insects which feed upon decaying animal matter present three 

 divisions : first, general scavengers, which devour particles of putrescent 

 matter wherever they may be found ; second, those which live exclu- 

 sively in or upon the bodies of dead animals, (Wecrophaga) ; and thirdly, 

 those which are found exclusively in animal excrement, {Coprophaga). 



The herbivorous insects may be divided in a similar manner into those 

 which eat fresh vegetable food, {Thalerophaga), and those which subsist 

 u])on vegetable matters in a state of decsty, {Saprophaga). They can 

 also be usefully classified according to the particular parts of the plant 

 which they devour, into lignivorous or wood-eating insects, {Xylophaga); 

 the folivoro us, or leaf-eating insects, [Phyllophaga); and the fructivor- 

 ous, or fruit-eating insects, {Carpophaga). 



The above Greek terms in parenthesis have been used chiefly in con- 

 nection with the insects of the Coleopterous order, in which these diver- 

 sities of food-habits exist to a much greater extent than in any of the 

 other orders, but the terms themselves are of general signification, and 

 being ver^ concise and comprehensive, they might, not improperly, be 

 used in speaking of insects in all the orders, so far as they are apj^Ul 

 cable. 



