220 DISEASES OF INSECTS. 



was to feed upon; though some appear to pierce it with 

 their ovipositor, and consequently introduce their egg 

 within : for he says afterwards ; " I have seen with my 

 own eyes a certain kind of wild flies deposit their eggs 

 upon other eggs, and bore and pierce others with an 

 aculeus by which they have introduced the egg a ." 

 Count Zinanni, a correspondent of Reaumur's, saw an 

 Ichneumon pierce the eggs with her ovipositor repeat- 

 edly ; which in about fifteen days were filled with the 

 pupa, and in six more produced the imago b . /. Ovu- 

 lorum L. is the only known species of egg-devourers ; 

 but most likely there are many, varying in size, accord- 

 ing to the size of the egg they inhabit. Probably 

 /. Atomus L., and /. Punctum Shaw, are of this descrip- 

 tion . It is wonderful what a number these little flies 

 destroy : out of a mass of more than sixty eggs which 

 was brought to De Geer, not one had escaped the Ich- 

 neumon d . But the most extraordinary thing is, that 

 even these little creatures we are told are destroyed by 

 another still more minute 6 . 



Though the animals we are speaking of usually destroy 

 only a single egg, yet some appear not so to confine 

 themselves. Geoffrey informs us that the larva of one 

 of the Ichneumons whose females are without wings 

 (Cryptus) devours the eggs of the nests of spiders, and 

 from its size it is nearly a quarter of an inch long 

 it must require several of them to bring it to matu- 

 rity f . One of those also which destroys the gnat infest- 

 ing the wheat (7. inserens] appears to devour them in 



a Vallisnieri Let fere, &c. 80. b Reaum. vi. 296. 



c Linne evidently has described another species under /. Ovidorum, 

 in Fn. Suec. 1644. d De Geer i. 593. 



N. Diet. d'Hist. Nat. vi. 10. f Geoff r. Hist. Ins. Par. ii. 361. 



