GRUBS. 



393 



tained the fact. In the spring of 1813, about two hundred 

 and thirty acres of 3'onng wheat are said to have been de- 

 stroyed by it ; and it is farther supposed to be the same 

 insect which caused great destruction in Italy in 1776. 

 This grub is said to take probably three years in coming to 

 a beetle, in which state it is alleged to clamber up the 

 stems at night to get at the corn. It is important to 

 remark, that along with these grubs were found those of a 

 chafer (Melolontha ruficornis^ Fabe.), in the proportion of 

 about a fourth.* 



T^ 



a, Zabrus gibbus ; b, Melolontha ruflcornis. 



To this account Mr. Stephens appends the shrewd ques- 

 tions — "May not these herbivorous larvas [of the chafer] 

 have been the principal cause of mischief to the wheat, 

 while those of the Zahrus rather contributed to lessen their 

 numbers than to destroy the corn ? And is it not probable 

 that the perfect insects ascend the corn for the purpose of 

 devouring the insect parasites thereon ? This is a subject," 

 he justly adds, "that requires investigation, as it is highly 

 important, for the interests of the agriculturists in those 

 districts where the insect abounds, that the question should 

 be thoroughly set at rest ; because, should the Zabri depart 

 from the habits of the group to which they belong, and 

 become herbivorous instead of carnivorous, their destruction 

 would be desirable ; while, on the contrary, if they destroy 

 the devourers of our produce their preservation should be 

 attempted, "t 



* Germar, Mag. der Entomol., i. 1-10 ; and Kirby and Spence, i. 169. 

 t Stephens, lUiistiations, i. Mandib. pp. 4 and 140. 



