38 THE ENTOMOLOGIST. 



LEPIDOPTEEA AT RANNOCH IN 1905. 

 By E. a. Cockayne, F.E.S. 



On May 17th we arrived at Eannocli, a party of three. The 

 weather being beautifully fine, we decided to go at once in search 

 of jhiarta cordigera and Fidonia carhonaria. 



After a rather warm climb through the birch -woods and the 

 heathery moor above, we reached the bare and rocky top of the 

 hill, where the bearberry grows hanging over the] rocks in long 

 trailing masses. 



We soon saw a single .4. cordigera, flying very fast, and 

 though we saw many more during the day, only captured three. 

 F. carhonaria we scarcely saw till nearly twelve o'clock, when 

 they began to appear on all sides, flying fairly actively, and, if 

 frightened, they were impossible^to^catch'[on the slippery and 

 uneven ground. The larva of this insect is said to feed on 

 birch and sallow, but I noticed that it was only met with where 

 bearberry was growing in abundance, and the females frequently 

 settled on this plant. There is plenty of birch and sallow on 

 this hill, but none on the part where the insect occurs. Pro- 

 bably, like A. cordigera, it is exclusively a bearberry-feeder. 

 F. carhonaria was easily distinguished from F. atomaria by its 

 greater powers of flight, its smaller size, and bluer appearance. 

 The latter, too, was much commoner at a slightly lower level. 

 The next few days the weather continued fine, and A. cordigera 

 was seen in considerable numbers in those isolated places where 

 the bearberry was sufficiently common. They appeared to spend 

 most of the day feeding on the flowers of this plant, or resting 

 on the ground. On one occasion, early in the afternoon, we saw 

 fifteen hovering together at the side of a large stone, as if 

 assembling. Several were caught, but no female could be found, 

 and I do not think there was one. They do not pair till dusk, 

 when they settle down for the night on the patches of bare peat 

 or on the rocks, always in a place sheltered from the wind, and 

 never many yards from a bearberry plant. Perhaps it was more 

 or less parallel to the instance, mentioned by Barrett in his 

 ' British Lepidoptera,' of an assemblage of Anarta myrtilli which 

 was undoubtedly attracted by a dead and dried-up moth, too 

 bleached to be identified. F. carhonaria flies chiefly from twelve 

 noon onwards, and is very susceptible to cold. One bright and 

 sunny, but very cold day, we did not see any fly naturally, and 

 could only put up two or three. 



We were surprised to find several Thecla rnhi on the blossoms 

 of the bearberry, and later saw them in abundance in the Black 

 Wood, settling on the clumps of whortleberry {Vaccinium vitis- 

 idcea). At the time I wondered what the larvae had fed on, but 

 find, on looking up the subject, that both these plants have been 

 recorded as food-plants of this butterfly. 



