1 76 [AlIRUst. 



1 



EXCESSIVE ABUNDANCE OF THE LARVAE OP 



CHARAEAS GFAMINIS IN JUNE 1917. 



BY G. T. PORETTT, F.L.S, 



The occurrence of tlie larvae of Charaeas fframinis in excessively 

 abnormal numbers, both in Britain and on the Continent in occasional 

 years, usually at long intervals, has been known to entomologists appa- 

 rently since the year 17-11 ; but in point of numbers and area affected, 

 the present jea,r has probably exceeded all previous records, at any 

 rate so far as the United Kingdom is concerned. The area affected ex- 

 tended to some sixty miles, in Cumberland, Westmorland, Lancashire, 

 Derbyshire, Cheshire, and Yorkshire. The larvae were in millions. 

 The localities included the Peak District ; extremely abundant at 

 Kinver End, Whaley Bridge, and near Castleton ; on all the high moors 

 between and aromid Hay field and Glossop ; moors north of Hey wood ; 

 and in certain of the Lake District Fells ; Chinley, Buxton, Chapel-en- 

 le-Frlth, Edale, Comb Moss, Kinder, Hope Woodhead, Clitheroe, Low- 

 gill, Gaping Cell; Hawes Jvmction to Sedbergh, especially in the Dent, 

 Garsdale, and Cautley Valley ; Deepdale, Uldale, Fellgate ; and near 

 Penistone at Dunford Bridge, Boadhill, Saltersbrook, Woodhead, etc. 

 In nearly all cases the trouble originated on the grassy parts of the 

 moorlands and hillsides, and when every vestige of grass was eaten oif in 

 such situations, the larvae migrated to the lower slopes, crossing roads 

 etc. in prodigious numbers to find more food. In the Penistone 

 district the roads were so infested that it is reported the parish steam- 

 roller was actually brought out to crush them ; and in some localities 

 the sheep-feeding districts were so bared of grass by tlie larvae, the 

 sheep had to be removed, nothing having been left for them to eat ! 



Dr. A. D. Imms, of the Dept. of Agricultural Entomology at the 

 Manchester University, made a careful investigation of the matter, and 

 reported thereon to the ' Journal of the Board of Agriculture.' I have 

 not as yet seen that report, but Dr. Imms has kindly given me some of 

 the inferences he arrived at, and very courteously allows me to make vise 

 of them in these notes. He says the " attacks were almost exclusively 

 confined to the grass known locally in Derbyshire as ' Bent grass.' 

 No good meadow grass or corn crops were found to be attacked. Upland 

 pastures and sheep-iTins at an altitude of 750 feet and over were attacked, 

 hut not below that elevation. This is, 1 think, mainly because the poor 

 kind of grass (Bent grass) has l>cen eradicated, and re])laccd by good 



