A HISTORY OF DURHAM 



of dredgings from various rivers and other materials brought as ballast by sailing ships. These, 

 as laid down, are overgrown with a vast variety of plants, many of which are not indigenous 

 to Durham ; and it would almost appear as though pupae had been brought in the ballast, as 

 well as seeds of strange plants, for many insects have occurred at these places that are not 

 otherwise known, some of which appear to have established themselves. 



Westward from the coast the land gradually rises, and after a wide expanse of arable and 

 pasture land, well wooded in places, we reach boggy moors, and high basaltic cliffs, almost 

 mountainous in altitude. Thus we have in Durham a littoral fauna, that pertaining to 

 cultivated land and to woods, and the fauna more closely allied with moor and mountain. A 

 deposit of coal underlies much of the county, which has been extensively mined, and in all 

 places where the pits open, large piles of waste accumulate. These take fire and burn for 

 many years, sending forth volumes of sulphurous smoke, which exercises a very deleterious 

 influence on all vegetable life for a considerable distance around. These have unquestionably 

 caused the disappearance of Lepidoptera in their districts. The growth of towns, and increase 

 of large works, sending forth volumes of smoke and vapour, have also had a very injurious 

 effect. In the suburbs, white butterflies and similar species occur freely enough, but others 

 need more secluded haunts. In many other ways the district is being altered. Even the 

 swamp at the mouth of the Tees is being pumped for brine, and roads and railways are 

 reaching even the most out-of-the-way places. 



RHOPALOCERA 



Butterflies 



The most noteworthy fact with regard to the butterflies of Durham to-day is the large 

 number that have disappeared during the Victorian era. Of the thirty-five butterflies 

 enumerated below, it would now be quite impossible to capture half of that number, even in 

 a most favourable season ; in fact, I doubt if many more than a dozen could be got with 

 certainty, even by visiting certain restricted haunts. 



The Common Whites, Pieris brassiere and rapa, are found everywhere except on the 

 higher moorland. They are most abundant in the outskirts of towns and villages, and about 

 market gardens, where cabbage and nasturtium are grown. The Green-veined White, 

 P. napi, is also common, but it is more frequently found in woods and country lanes than near 

 towns. The Orange-tip, Anthocaris cardamines, is generally common, but never so plentiful as 

 the preceding. It disappeared from the coast district about 1860, but has gradually returned to 

 its old haunts and is again plentiful there. The Clouded Yellow, Colias edusa t is but a casual, 

 occasional visitor, generally appearing when extra large swarms are visiting the south. In 

 1870, the great Edusa year, it was quite common in all parts of the county, and certainly bred 

 here, the imago, in perfect condition, being plentiful in the autumn, and a few apparently 

 hybernating, and appearing in the following spring. The Brimstone, Gonopteryx rhamni, is 

 not a native of this part of England ; indeed, the food-plant does not grow wild in Durham, 

 and only one or two stray specimens of the butterfly have been noticed within the boundaries 

 of the county. 



The Silver-washed Fritillary, Argynnis paphia, was taken in Castle Eden Dene at least as 

 late as 1855. It also occurred at Gibside and other places in the north-west of the county. 

 In 1853 it was taken at Darlington, but I have seen no more recent records than these, 

 even of stray specimens. The Dark Green Fritillary, A. agtaia, was formerly comparatively 

 common, occurring in Castle Eden and Hesleden Denes, and on the coast at Black Hall 

 Rocks, and elsewhere. It was common, also, in most of the cultivated area within the 

 county, Bishop Auckland, Chester-le-Street, and various places in the Derwent Valley. It 

 has now quite left the coast, but is still plentiful in the Wear Valley, and westward. At 

 Byers Green a very fine dark variety was taken some years ago by Mr. Thomas Hann. It was 

 all suffused with dark scales, not like the Vahzina variety of Paphia, but a rich, dark fulvous. 

 The Pearl-bordered Fritillary, A. euphrosyne, was formerly common in all parts of the county. 

 It disappeared from Castle Eden Dene and other coast localities in the early sixties, but it 

 is still common in the west, and especially in the north-west. It is abundant about Stanley, 

 and larva; may be found freely. The small Pearl-bordered Fritillary, A. se/ene, was also widely 

 distributed and common, but not so abundant as Euphrosyne. It still occurs about the western 

 portions of the county and adjoining district. A specimen was taken in Hesleden Dene some 



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