FOOD OF INSECTS. 253 



as the infinite hordes of the field-bug tribe. And the larvae of the gnat, 

 chameleon (^Stratyomis), and other flies aquatic in that state, the leviathans 

 of the world of animalcules, swallow whole hosts of these minute inhabi- 

 tants of pools and ponds at a gulp, causing, with their oral apparatus, a 

 vortex in the water, down which myriads of victims are incessantly hurried 

 into their destructive maw. 



But not only animals themselves, almost every animal substance that 

 can be named is the appropriate food of some insect. Multitudes find 

 a delicious nutriment in excrements of various kinds. Matters apparently 

 so indigestible as hair, wool, and leather, are the sole food of many moths 

 in the larva state (Tinea iapetzella, pellionella, &c.). Even feathers are 

 not rejected by others ; and the grub of a beetle (Anthrenus Musaorum), 

 with powers of stomach which the dyspeptic sufferer may envy, will live 

 luxuriously upon horn.^ 



For the most part, insects feeding upon animal substances, will not touch 

 vegetables, and vice versa. You must not, however, take the rule without 

 exceptions. Many caterpillars (as those of Thyatira derasa, Chariclea 

 Delphinii, &c.), though plants are their proper food, will occasionally 

 devour other caterpillars, and sometimes even their own species. The 

 large green grasshopper (Acrida viridissima), and probably others of the 

 Order, will eat smaller insects as well as its usual vegetable food^ ; so also will 

 the larvae of many Phnjganea. Allantus marginellus, as I was last summer 

 amused by witnessing, like many Scotophaga, sips the nectar of umbel- 

 liferous plants only till a fly comes within its reach, pouncing upon which 

 it gladly quits its vegetable for an animal repast. Anobium paniceum, 

 which ordinarily feeds upon biscuit, was, as I have before mentioned, once 

 found by Mr. Sheppard in great abundance living upon the dried Cantha- 

 rides (Cantharis vesicatoria) of the shops. On the other hand, Necropho- 

 rus mortiiorum, which subsists on carcasses, and many other carnivorous 

 species, will make a hearty meal of a putrid fungus. Ptinus Fiir devours 

 indifferently dried birds or plants, not refusing even tobacco; and from the 

 impossibility that one of a million of the innum.erable swarms of gnats 

 which abound in swampy places, particularly in regions which but for 

 them would be lost to sensitive existence, should ever taste blood, it seems 

 clear that they are usually contented with vegetable aliment. Indeed the 

 males, as well as those of the horse-fly, of which even the females readily 

 imbibed the sugared fluid offered to them by Reaumur"^, never suck blood 

 at all ; so that they must either feed on vegetable matter, which in fact I 

 have observed them to do, or fast during their whole existence in the per- 

 fect state. 



Though insects, generally considered, have thus a much more extensive 

 bill of fare than the larger animals, each individual species is commonly 

 limited to a more restricted diet. Many both of animal and vegetable 

 feeders are absolutely confined to one kind of food, and cannot exist upon 

 any other. The larva of (Estrus Equi can subsist no where but in the 

 stomach of the horse or ass ; which animals, therefore, this insect might 

 boast with some show of reason to have been created for its use rather 

 than for ours, being to us useful only, but to it indispensable. The larva; 

 of Scceva Pyrastri, according to De Geer, eat no other Aphis but that of 



' De Geer, iv. 210. « Brahm, Insekten Kalender, i. 190. ^ Reaum. iv. 280. 



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