386 FOOD OF INSECTS. 



of these minute inhabitants of pools and ponds at a gulp, 

 causino- 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 in- 

 digestible as hair, wool, and leather, are the sole food of 

 many moths in the larva state ( Tinea tapetzella, pellio- 

 nella, &c). Even feathers are not rejected by others ; 

 and the grub of a beetle (Byrrhus Mus&orum, L.), with 

 powers of stomach which the dyspeptic sufferer may 

 envy, will live luxuriously upon horn a . 



For the most part, insects feeding upon animal sub- 

 stances will not touch vegetables, and vice versa. You must 

 not however take the rule without exceptions. Many 

 caterpillars (as those of Noctua derasa, Delpkinii, &c), 

 though plants are their proper food, will occasionally 

 devour other caterpillars, and sometimes even their own 

 species. The large green grass-hopper (Locusta viridis- 

 sima, F.), and probably others of the order, will eat 

 smaller insects as well as its usual vegetable food b ; so 

 also will the larvae of many Phryganece. Tenthredo mar- 

 ginella, F., as I was last summer amused by witnessing, 

 like many Scatophagy sips the nectar of umbelliferous 

 plants only till a fly comes within its reach, pouncing 

 upon which it gladly quits its vegetable for an animal 

 repast. Ptinus rubellus, Ent. Brit., which ordinarily feeds 

 upon wood, was, as I before mentioned, once found by 

 * De Geer, iv. 210. b Brahm, Insekten Kalender y i. 190. 



