BITHYS QUERCUS. 



253 



having no other resource than the leaves on which it had been 

 feeding, quite small ones, less than one inch in length, went to the 

 bottom of the jar and drew three or four of these together, with some 

 rather feeble threads of pale silk, forming, however, a cocoon or cavity 

 so as to completely hide the larva, except through a crack or two 

 betw r een the leaves. In this it rested, dorsum upwards, and the larva 

 pupated by the afternoon of May 13th. On May 25th, 1906, five larvaB 

 cocooned together amongst some oak-leaves on which they were sup- 

 posed to be feeding. They are, in tw T o instances, two placed close to- 

 gether, the other separate. They have drawn the leaves round them as 

 a definite cocoon, closed either by the leaves themselves, or by a 

 thin network of silk closing the open end. It is to be noted that 

 these larva? had no opportunity of 'going down.' " Eothke observes 

 that, at Krefeld, the larva of B. quercus pupates on the ground. 

 Rossler says that, at Wiesbaden, it pupates on the surface of the 

 ground under leaves. Glaser says that he obtained larvas abundantly 

 in the "Hinterland," in Hesse, and from 20 to 30 of these changed 

 intopupre, without spinning a girth, and under moss. Cole notes (Ent., 

 v., p. 355) rearing a specimen, July 9th, 1871, that he believed came 

 from a pupa of the previous year. Borkhausen noted the pupal stage 

 as lasting fourteen days, sometimes less ; Ochsenheimer gives fourteen 

 days, Roesel sixteen clays, Glaser twelve days, and Nolcken 20 days. 



Maturation of pupa. — A larva pupated during the afternoon of 

 May 13th, 1907. The pupa, after some three or four hours, is mature 

 as to form, but is still very definitely coloured, if it may be so expressed, 

 in larval colour and markings. Ventrally, the wings and appendages 

 form the greater part of the surface, but not only these, but the 

 head and the ventral surface of the 5th and following abdominal 

 segments are colourless, transparent, and pellucid. Laterally, the 

 spiracles are white on a pale area, and below them, on the exposed 

 abdominal segments, is a reddish line (the marginal flange), then a 

 pale line (the incision or suture between the marginal flange and the 

 one below it), then a reddish line (the second flange bordering the 

 pale under- surface). These flanges are, therefore, well marked in 

 colour, but are not marked by any trace of ridge (or hump) or incision, 

 the white surface being very smoothly rounded. Dorsally, the thorax 

 is already assuming something of the permanent pupal colouring; it is 

 greyish-ochreous, pellucid-looking, and has a dark dorsal line and dark 

 reddish lines at a lower level, most marked on the mesothorax, making 

 a long oval, with the dorsal line as its long axis. This is really the 

 oblique (larval) line, stretched out by the expansion which the meso- 

 thorax undergoes in the pupa, the posterior line of the oval, being the same 

 line of the metathorax shortened and crowded dorsally. Some fuscous 

 marblings are superficial and are proper pupal colour. The abdomen 

 is very reminiscent of the larva, it is almost bright red, with a dark 

 (reddish-brown), dorsal line, and a dark (oblique) mark halfway be- 

 tween this and the margin (as seen from above) of a similar colour, on 

 the 2nd to 7th abdominal segments, and in each of the marks a small 

 round black spot that looks depressed. Under a low power (hand-lens) 

 it looks a definite, small, circular hollow, but, more magnified, it is 

 equally a depression, but with regular sloping sides, it is without 

 spiculate- (umbrella-) hairs, these are elsewhere (not on appendages) 

 evenly distributed and rather abundant. In this fresh pupa they are 



