1917.]' 177 



meadow grass. Couch grass ( Triticiim repens) and the more succulent 

 and liner grasses were not touched. Vast numhers of the" larvae Avere 

 seen personally, and wherever the attacks were had, the grass was eaten 

 away, leaving dry hare hillsides. Farmers whose lands were confined to 

 upland areas lost severely from the destruction of the grassy fields. 

 Causes of the outbreak are seemingly due to — (1) scarcity of birds, more 

 especially the Lapwing; (2) the effects of the severe winter, which 

 sealed up the ground from the attentions of birds for an exceptionally 

 long period ; (8) the absence of interiuittent mild spells when birds make 

 considerable inroads into insect life ; (4) Defence of the Realm llules, 

 which have restricted the burning of moorlands and mountain grass 

 areas." 



That Dr. Imms found only the " Bent grass" * to be attacked is 

 noteworthy, as in my one experience in rearing a considerable number of 

 the larvae, sent to me from Clitheroe during the similar occurrence in 

 the Pendle Hill district in 18S1, I found they would eat greedily any 

 grass offered to them. And this has been the experience of others who 

 have reared the larvae since then ; as it w^as also of the late William 

 Buckler (' Larvae of British Butterflies and Moths,' vol. iv, p. 67). 



An anonymous correspondent of the 'Yorkshire Post' of June 19th, 

 but who evidently knew what he was writing about, gave a list of the 

 records of the serious devastations of these larvae as follows :^ 



17-41 and 1748. — Sweden, ravages so vast as to be a national 



calamity. 

 1810 and 1817. — Hartz Mountains. 

 1827. — Skiddaw, Cumberland, level part of 60 acres of grass 



devoured. 

 1881. — Clitheroe, Lancashire, Pendle Hill area. 

 1884. — Glamorganshire, a 50 miles area west of llhondda Valley 

 1885. — Sellvirkshire, a 35 miles area of hill-pastui-es. 

 1897. — Carnarvonshire, about 19 acres. 

 1902. — Cumberland, mountain area. 

 1917. — Peak District, Derbyshire etc. 

 It is as well to place these instances on a more permanent record. 



Elm Lea, Daltoii, Iluddersfield. 

 July llth, 1917. 



* Dr. Imms tells me that the " Bent grass " has been iilcntiCud at Kew as Nardm stricla. 

 —G. C, C. 



