-tOG RAVAGES OF INSECTS. 



bringing herself into a horizontal position. The maggot, 

 when hatched from the egg, immediately attacks the roots 

 of the grass and other herbage which it finds nearest to it ; 

 and of course the portion of the plant above ground withers 

 for lack of nourishment. 



The maggots of this family which seem to do most injury 

 are those of Tipula oleracea and T. cornicina. In the summer 

 of 1828, we observed more than an acre of ground, adjoin- 

 ing the Bishop of Oxford's garden at Blackheath, as entirely 

 stripped, both of grass and everything green, as if the turf 

 had been pared off from the surface, the only plant un- 

 touched being the tiny bird-tare (Or)iithojms perpusillns^. 

 On digging here to learn the cause, we found these larvae 

 already full-fed, and about to pass into pupa^, after having 

 left nothing upon which they could subsist. It was not a 

 little remarkable that they seemed to be altogether confined 

 to this spot ; for we did not meet with a single foot of turf 

 destroyed by them in any other part of the heath, or in the 

 adjacent fields. So very complete, however, M^as their 

 destruction of the roots on the spot in question, that even 

 now, at the distance of two years, it is still visibly thinner 

 of herbage than the parts around it. (J. R.) 



Eeaumur gives a similar account of their ravages in 

 Poitou, where, in certain seasons, the grass of the low moist 

 meadows has been so parched up in consequence, as nojt to 

 afford sufficient provender for the cattle. He describes the 

 soil in Poitou as a black peat mould ; and it was the same 

 in which we found them at Blackheath, with this difference 

 that the sj)ot was elevated and dry. According to M. 

 Eeaumur, also, their only food is this sort of black mould, 

 and not the roots of grass and herbage, which he thinks are 

 only loosened by their burro Aving.* This view of the 

 matter appears strongly corroborated by the fact that 

 several species of the family feed upon the mould in the 

 holes of deca^dng trees, particularly the larva of a very 

 beautiful one (^Ctenophora Jiaveolata, Meigen), which is very 

 rare in Britain. It is proper to mention, however, that 



* Reaunim-, v. 12, &c. 



