A CATALOGUE OF THE LEPIDOPTKKA, ETC. 189 



VIII. — A Catalogue of the Lepidoptera of Northumberland and 

 Durham. By George Wailes, Member of the Entomolo- 

 gical Societies of London, France, and Stettin. 



[Read May 19, 1857.] 



To prepare a perfect Entomological Fauna of even the most 

 circumscribed district, is, from the very nature and habits of tho 

 creatures to be enumerated, impossible, and any approach to com- 

 pleteness as regards the Lepidoptera, most difficult. Whilst in 

 other orders of insects the term of existence in the perfect or 

 imago state, generally extends over periods of several weeks or 

 even months, that of the Lepidoptera is usually confined to a 

 few days, and therefore, unless the collector can avail himself of 

 the short period each particular species is known to be " on the 

 wing," he has little chance of adding it to his list. It is very 

 true that a number of the species (which number is being rapidly 

 augmented through the labours of both British and Continental 

 Entomologists) hybernate, but the greater portion of such 

 species keep themselves so effectually concealed, that the oppor- 

 tunities of noticing them are thereby in reality little increased. 

 The exclusively nocturnal habits of nineteen-twentieths of these 

 insects, contribute still further to the difficulty of ascertaining 

 whether or not they are entitled to rank in a local fauna. For- 

 tunately, however, an earlier state of their existence affords the 

 Lepidopterist the means of detecting many that he never meets 

 with in the perfect state, in which indeed several of the more 

 minute species have not yet been found at large ; and in the fol- 

 lowing Catalogue, I shall have occasionally to include species of 

 which the larvae alone have been captured within the district. 



The immediate vicinity of Newcastle is not at all favourable 

 to the development of these insects — the cold clayey soils, added 

 to the high cultivation of the land, which has almost denuded it 

 of trees, and reduced the hedge rows to the least possible di- 

 mensions, offer little encouragement to insects that revel in the 

 luxuriant herbage and sheltered spots of districts more nearly in 

 a state of nature. It is, therefore, to the wooded vallies of the 



VOL. III. PT. IV. 7. 



