14(3 Insect Fauna of Permanent Pasture 



predominated. An analysis of a typical area gave the following results 

 in percentages by weight: 



Gramineae 



Agrostis alba and A. vulgaris 44-1 



Cynosurus cristatus ... ... 30-3 



Lolium perenne ... ... 9*4 



Poa spp 3-5 -87-3 



Leguminosae 



Trifolium spp. ... ... 5*6 



Other orders (regarded as weeds) 7-0 



Under the latter category the following may be mentioned: 



Abundant : Ranunculus acris, R. repens, Bellis perennis, Brachythecum 

 rutabulum. t 



Common: Holcus lanatus, Plantago lanceolata, Urtica dioica, Carduus 

 arvensis, Cerastium triviale. 



Occasional: Polygonum persecaria, Plantago major, Ajuga reptans, 

 Hieracium spp., Luzula campestris, Rumex acelosa. 



Urtica dioica occurred in two or three patches in the field and also 

 in the hedges in a few places. Luzula campestris occurred in the lower 

 and damper part of the field. 



The hedge-bottoms were fairly clean owing to those of the College 

 farm being occasionally dug over. In addition to most of the above 

 species, the hedges also contained species of Rumex. A moss, probably 

 Brachythecum rutabulum, formed an almost continuous covering to the 

 soil, although obscured by the taller plants from casual observation. 



6. Methods of Investigation. 



The investigation was carried out in the following manner. The turf 

 and soil of an area ten inches square was removed entire to a depth of 

 two inches. The soil below was then removed in layers, each layer being 

 examined separately so that the depth at which the insects occurred 

 could be determined. This examination was carried out in the field, and 

 on several occasions the soil was examined to a depth of two feet,but 

 as very few insects were found at a greater depth than two inches, one 

 foot was usually considered a sufficient depth to examine. 



The upper layer, consisting of the turf and surface soil, was placed in 

 a box and taken to the laboratory, as, owing to the presence of roots and 

 of almost all the soil insects, this sample required more careful ex- 

 amination. 



