242 THE ENTOMOLOGIST. 



ROUND THE CHESTER ELECTRIC LAMPS. 



By J. Aekle. 



If the suburbs of a town, or indeed any part of one, are free 

 from smoke and noisome vapours, and planted with trees and 

 gardens and shrubberies, the entomologist will find moth-hunting 

 by the electric lamps very profitable. On the other hand, if the 

 conditions are unfavourable in the immediate neighbourhood, 

 electric or other lamps do not appear to be worth working ; 

 there should be varied, or at any rate existing, vegetation, with 

 the accompanying circumstance of fairly pure air. Let me quote 

 the following illustrations in support of what, I am prepared to 

 admit, may be a rule and not a law. A large electric lamp — 

 high up and very conspicuous — at the Winter Gardens, More- 

 cambe, only attracted, July, 1889, Acidalia scutulata, Xylophasia 

 polyodon, Triphcena pronuba, and Plusia gamma (Entom. xxii. 

 296). The more interesting moths of Hey sham Moss, three 

 miles away, did not put in an appearance at all. I have no 

 doubt the results would have been different had there been well- 

 clothed sandhills about. Morecambe, in short, was deficient in 

 the "greenery" conditions, although its air is of the freshest. 

 Again, at Chester, we have now a varied vegetation almost 

 luxuriant. The lime flourishes in our streets and suburbs, and on 

 July 19th the air was laden with the scent of its pendent bunches 

 of yellow blossoms. There are also the poplar, birch, beech, 

 sycamore, and horse-chestnut, together with endless privet and 

 hawthorn, and ornamental willows and sallows. I specially select 

 these trees and shrubs since they account for all, or nearly all, 

 the best moths we take at the electric lamps, and because many 

 of them are either replaced by other species — a mile or so away, 

 and then for a large area — or they are almost non-existent. 

 Thus the lime is replaced by the oak ; the birch, beech, and 

 horse-chestnut practically cease ; the hawthorn continues ; but 

 the sallow, willow, poplar, and privet become scarce. The con- 

 clusion, therefore, would seem to be this — the life-histories of 

 the extraordinary species we have taken during the past two 

 seasons (Entom. xxxi. 299) at the electric lights are confined to 

 little more than the area actually illuminated by the lamps 

 themselves. The best lamps are those where the vegetation 

 referred to is most profuse. Again, there are species of moths 

 recurring, year after year, only a mile away from the city, 

 which, it would be pretty safe to say, are never attracted. I 

 only know of one puzzling species, Agrotis porphyrea, which 

 frequently occurred, fine and fresh, in June and July. I have 

 searched in vain for any food-plant of the insect other than 

 heath, and conclude that this apparent exception to the rule is 

 due to my ignorance of all its pabulum. How species locate 



