INDIRECT BENEFITS DERIVED FROM INSECTS. 255 



whose singular manoeuvres I shall subsequently have to 

 advert to, Copris lunaris, Scarabceus stercorarius and 

 many others of the Scarabceidce, make large cylindrical 

 holes, often of great depth, under the heap, and there 

 deposit their eggs surrounded by a mass of dung in which 

 they have previously enveloped them ; thus not only di- 

 spersing the dung, but actually burying it at the roots of 

 the adjoining plants, and by these means contributing 

 considerably to the fertility of our pastures, supplying 

 the constant waste by an annual conveyance of fresh 

 dung laid at the very root ; by these canals, also, af- 

 fording a convenient passage for a portion of it when 

 dissolved to be carried thither by the rain. 



The coleopterous insects found in dung inhabit it in 

 their perfect as well as imperfect states : but this is not 

 the case with those of the order Diptera, whose larvse 

 alone find their nutriment in it ; the imago, which would 

 be suffocated did it attempt to burrow into a material 

 so soft, only laying its eggs in the mass. These also are 

 more select in their choice than the Coleoptera — not in- 

 deed as to delicacy, — but they do not indiscriminately 

 oviposit in all kinds, some preferring horse-dung, others 

 swine's-dung, others cow-dung, which seems the most 

 favourite pabulum of all the dung-loving insects, and 

 others that of birds. The most disgusting of all is the 

 rat-tailed larva that inhabits our privies, which changes 

 to a fly {Elophilus tenax^ Latr.) somewhat resembling 

 a bee. 



plays of Aristophanes, the Irene, where a beetle of this kind is introduced, 

 en which one of the characters rides to heaven to petition Jupiter for 

 peace. The play begins with one domestic desiring another to feed the. ' 

 Cantharus with some bread, who afterwards orders his companion to give 

 liim another kind of bread made of assci dung. 



