218 FOOD OF li^ SECTS. 



Another numerous class kill their prey outright, either devouring its solid 

 parts, as the predaceous and rove-beetles, &c., or imbibing its juices only, 

 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 de- 

 licious 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 tapetzella, jjeUionclla, &c.). Even feathers are not 

 rejected by others ; and the grub of a beetle {Anikremts MuscBoriim), with 

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

 ously 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 Thi/atira derasa, Chariclea 

 Delj)lnnii, &c.), though plants are their proper food, will occasionally de- 

 vour 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 larvas of many Phygmiece. Allantus marginellus, as I was last siunmer 

 amused by witnessing, like many Scalophagce, 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 jmniceum, which 

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

 by Mr. Sheppard, in great abundance living upon the dried Cantharides 

 {Cantharis vesicatorid) of the shops. On tlie other hand, Necrojyhorus 

 moriuoj-ian, which subsists on carcasses, and many other carnivorous 

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

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

 the impossibility that one of a million of the innumerable 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 do, or fast during their whole existence in the perfect 

 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 CEslrus Eqid can subsist nowhere 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 



» De Geer, iv. 210. 2 Brahm, Insekten Kalender, i. 190. 



5 lieaum. iv. 280. 



