312 BRITISH BUTTERFLIES. 



observed them resting or walking with their wings closed, but, on the 

 heath, they have always had their wings spread out. In Wales, it is 

 recorded as being observed flying round the tops of trees, near 

 Machynlleth, and Crotch states (ZooL, 1856, p. 5291) that, in 

 August, 1856, he found the species excessively abundant throughout 

 the Valley of the Dovey, in Montgomeryshire, where it had apparently 

 departed from its usual habit, since, by far the greater number were 

 captured on the tops of oak-trees, in company with Bithys quercus, 

 and, strange to say, the former were by far the more abundant. The 

 following year he recorded (Ent. Wk. Int., ii., p. 166) that, in North 

 Wales (evidently not far removed from Shrewsbury), R. betulae 

 commenced to appear on August 9th, 1857, the first appearances 

 always consisting of males. This species, here, he says, usually 

 accompanies, and fights furiously with, B. quercus on the oak, but is 

 rather more ready to settle, and thus falls an easier prey. A windy 

 day drives them all to the lee of the wood, and then one is able 

 to take them more freely, but wind certainly injures them more 

 than rain, and fighting more than either. Burt also states (in litt.) that, 

 in Pembrokeshire, the insect almost always rests on oak, from 15ft. to 

 20ft. from the ground, and is rarely to be seen down. Dollman states 

 that, from July 26th to September 10th, 1900, between Burgess Hill 

 and Hassocks Gate, he saw the species flitting over the bushes and 

 trees by the plantations at the roadside. Spiller observed several 

 examples in August, 1893, at rest upon blackthorn at Taunton ; 

 and Porritt says that he observed several females in September, 1902, 

 flying about blackthorn bushes on the South Devon coast. In Ger- 

 many, the habits of R. betulae have been little studied. It is noted as 

 flying chiefly in gardens and orchards, and the outskirts of woods in 

 Posen, Silesia, Brandenburg, Saxony, Mecklenburg, Hanover, etc., and 

 Prideaux observed it flitting about on the outskirts of the woods at Wies- 

 baden. In Switzerland, Blachier says that it occurs even in the gardens 

 of Geneva, flying about the fruit-trees. At Certosa di Pesio, Norris 

 records (Ent., xxv., p. 240) this species as flying over chestnut-trees, 

 near the old castle of Chiusa, and having a strong predilection for 

 certain trees, branches, and even leaves. Their flight, he says, is bold 

 and rapid, and if by chance two met, they circled round each other up 

 and out of sight. A pole quite twenty feet long fixed to the net, was 

 necessary to take them. They appeared to fly chiefly from 9 a.m. to 

 11 a.m., and during the great noontide heat they were very inactive. 

 Lambillion observes that, in Belgium, it loves to rest in the sun on the 

 leaves of trees, on hedges, and on the flowers of waste places ; it is, he says, 

 not very wary, and one captures it easily. In England, in some years, 

 it is much more abundant than in others, and the same fact is 

 noted in some of its French localities, e.g., Constant observes that in 

 the dept. Saone-et-Loire it is usually very common, but not every 

 year, for in some seasons it is almost altogether wanting. 



Habitats. — The outskirts of woods, the clearings in woods, the 

 rough overgrown hedges near woods, and the bush-covered slopes 

 leading up to wooded heights where sloe grows abundantly, are the 

 chief haunts of this species in south-eastern England. In Wales and 

 Ireland, it rather affects lanes, but nowhere is it found as a common 

 garden insect as in most parts of the continent, for, although essentially 

 here restricted to blackthorn, on the continent it is equally addicted to 

 plum, and to a less extent to apricot, as a foodplant, and so one finds 



