142 Insect Fauna of Permanent Pasture 



The investigation was carried out from the Department of Agricultural 

 Entomology, Manchester University, and the work finally completed at 

 Rothamsted. 



2. Description of the District. 



This region is mainly devoted to the production of milk, and a large 

 proportion of the area is occupied by permanent pastures for the grazing 

 of the dairy cattle. The fields in this district are usually small compared 

 with those in other parts of England, about ten acres being a common area. 



They are almost universally separated by hedges of hawthorn, often 

 very much overgrown, and overrun with bramble and dog-rose, together 

 with holly and occasionally furze-bushes. These hedges often stand on a 

 low bank and, in addition to the above mentioned shrubs, usually contain 

 a few trees, the commonest being the oak. Similar trees are also often 

 found away from the hedges, scattered about the fields. These hedges 

 and trees give the district, when seen from a distance or from a slight 

 elevation, a very well-wooded appearance, which, however, is not so 

 noticeable on a closer examination. These trees are almost always rather 

 small and stunted owing, probably, to their being scattered about singly 

 and not usually gathered together in woods or coppices. 



Another very noticeable feature of the district is the number of 

 ponds which are present, several often being found in a single field. 

 Many of these ponds have formed where pits were dug in order to obtain 

 the marl which underlies this district, and which was formerly spread over 

 the fields, owing to the general shortage of lime in the soil of the district. 



The small wood indicated on the map consists of beech, oak, alder, 

 ash, and sycamore, with some holly, hawthorn, mountain ash, and elm, 

 with an undergrowth of elder and hazel. 



The crops grown on the arable fields in the immediate neighbourhood 



during the period of the investigation were: 



Field 1916 1917 



A Potatoes; oats Oats; wheat 



B Wheat; oats Oats; clover and grass mixture 



C Potatoes; mangolds; swedes Wheat; oats 



D Wheat; oats; rye grass Oats; clover and grass mixture 



E Clover and grass mixture Clover and grass mixture 



G Clover and grass mixture; oats Mangolds; swedes; oats; potatoes 



H Oats Clover and grass mixture 



I Clover and grass mixture Oats 



M Temporary pasture laid down 1914 



N Nursery of seedling conifers sown 1916, previously pasture 



P Potatoes Oats 



Q Oats Oats 



R Wheat; oats kSwedes; mangolds; clover and grass mixture 



