252 BRITISH BUTTERFLIES. 



view ; on a side view, the back has the same green transparency as 

 elsewhere. The first spiracle is an obvious ochreous spot ; the others 

 are less conspicuous. The prothoracic plate shows a white central 

 line, shaded dark on either side, and the margins also are dark ; there 

 are black hair-points, closely set, as on the general skin-surface. 

 No trace of a girth can be seen (Chapman). 



Foodplants. — Quercus robur (Newman), Q. cerris (Rogenhofer), Q. 

 lusitamca (Walker), a species of oak with downy undersides to leaves, 

 allied to Q.pubescens (Nicholson), Q. pedunculata (Richter), Q. sessiliflora 

 (Pabst). Barrett notes a larva found on oak-apple, at Haslemere ; the 

 diet was continued to maturity, but the resulting imago was very small. 

 [Egg laid on "sallow" (Bignell, Ent. Mo. Mag., xiv., p. 112) ; " sallow " 

 is not known as a foodplant.] [Lienig found the larvae on Piitnus 

 padus (Nolcken, Lep. Faun. Estl., p. 52). Liiders found a larva 

 on Myrica gale and reared it up on this plant (Sorhagen, Illus. Zeits. 

 fur Ent., iv., pp. 259-261.) These want confirmation.] 



Parasites. — Pimpla mixta (Rondani), E.rorista vulgaris (teste 

 Watkins). The caterpillars of Bithys quercus are often parasitised, and 

 contain the larvae of a fly with stiff bristles; the parasitic larva allows 

 the host to pupate, when its own pupation takes place within the pupa 

 it has already killed (Steinert). 



Puparium.— Lewin gave, to an early race of British lepidopterists, 

 the statement that the larvae of this species prepared for pupation by 

 fastening themselves round by the middle and by the tail with a 

 slender web against the small branches or twigs of the tree on which 

 they have fed. Sepp, however, noted (Bescliouwing der Wonderen Hods, 

 iii., pt. 3, pi. xlv) the larva as spinning up for pupation between two 

 leaves. In 1833, Bromfield recorded (Ann. Mag. Nat. Hist., ser. 1, 

 vol. vi., p. 189) that several larvae in his possession, taken in the 

 neighbourhood of Plymouth, all retreated below the surface of the 

 earth placed in the bottom of the breeding-cage, pupated there, and 

 produced imagines in due course. Harpur-Crewe observes that the 

 larva of this species, when fullfed, descends the trunk of the tree, 

 spins a slight web among the roots of grass, and therein pupates. 

 Davis writes (in lift.) that, in the early evening of June 30th, 1902, in 

 the Stroud district, he took a larva as it was crawling down the bole 

 of an oak, which produced an imago on July 19th, 1902. Stainton 

 says (Man., i., p. 54 ) that the statement that the larva of this species 

 undergoes its transformation below the surface of the ground is perfectly 

 substantiated. Newman says that, " in captivity, the larva spins no 

 cocoon, nor does it fasten itself by any belt, or anal hooks, as is the 

 manner of its tribe, but. retires just below the surface of the earth, and 

 there turns to an obese, unangled, brown pupa." llellins says : " For 

 pupation the larva spins a lew threads, making- a frail sort of cocoon 

 just, on the surface of the earth, or availing itself of the shelter of a 

 fallen leal'," whilst Bowles notes that the larva spins a loose silken web 

 to enclose itself, and the pupa is. he says, as often as not. fixed to the 

 silken strands by the ana] hooks. Tin- error here is doubtless due to the 

 pupa, sometimes adhering to the larval skin, and this to some surface. 

 Tins is occasional with all Ruralid pupae without cremasters, and is 

 probably the rule with some. As there arc 1 no anal hooks, it is 

 obvious this observer inferred them only, but he probably did observe 

 Borne fixation. Chapman writes: ''On May 11th, 1907, a larva, 



