404 BRITISH LEPIDOPTERA. 



not half an inch long ; in May following they had grown little, but 

 slowly developed and added new pieces to their cases, so that by 

 October, 1899, they appeared to be almost (or quite) full-grown; these 

 have hybernated again and will no doubt spin up in May, possibly without 

 much further feeding (Cowl). Weir says that the larvae hatch in 

 about 10 or 12 days, and that they have been observed to lengthen 

 their cases by additions to either the proximate or distant end. Fowler 

 states that the young larvae, as soon as hatched, make cases of the 

 woolly lining of the puparium,feed up quickly, and by the autumn are 

 half- grown and may be picked up in this condition throughout the 

 winter (hybernating very low down on ling) ; in March they commence 

 to feed again — on Call una preferably — drop to the ground at once if 

 disturbed and do not commence to crawl for some little time, then 

 a larva protrudes its head, takes hold of a twig, draws itself along by a 

 series of sharp jerks until it has reached a safe place on the plant 

 again. Its ability to close its case when disturbed is remarkable. The 

 female larvae climb high upon furze-bushes, or pine-trunks to spin up 

 for pupation, the male larvae almost invariably pupate on the stems of 

 Calluna. Bacot notes that, in confinement, for the purpose of 

 hybernation the larvae appear to prefer an elevated situation, many 

 being attached to the gauze covering of the tub in which they are 

 confined, others on the sides of the tub, others on twigs ; altogether 

 there are some 80-100, all, however, firmly spun up. McEae says 

 that the larvae take two years to reach their full growth and that they 

 then select Calluna, furze, or the trunks of pine-trees on which to 

 pupate. Barrett observes that, " in confinement, larvae are sometimes 

 obstinate as regards food, existing sometimes for months without any, 

 at other times releasing the case after spinning it down tightly as 

 though for pupation and then feeding on for months so as to pass over 

 another year." We suspect that neither of these habits has anything to 

 do with the food supply. All larvae tbat pass a second winter," do so 

 practically full-grown, and spun down from October bo March ; they also 

 spin their cases down temporarily for some days at each exuviation ; 

 large larvae that have gone over their second winter are certainly easily 

 reared if fully exposed to the sun and supplied with fresh food. On 

 June 3rd, 1899, we noticed that full-grown larvae cling very tightly to 

 any object by means of their true legs and allow themselves to be drawn 

 partly out of the cases before loosening their hold. Having protruded 

 the .anterior part of the body to the 2nd or 3rd abdominal segment a 

 larva draws the rest of its body after it, in a more or less Geometrid 

 fashion, in short jerks, the case being pulled along after it suddenly, 

 the larva stretches out again and so on as before, the weight of the 

 case keeps it almost horizontal on the surface of the ground, or, if the 

 larva be climbing, the case hangs almost vertically. The head is quite 

 retractile within the prothorax and the other thoracic segments more 

 or less retractile within each other. The slightest disturbance of the 

 case, or even of the object on which it is resting, is sufficient to make 



* As bearing on the statement that the larvas take two years to come to 

 maturity, Rossler states that although Wocke gives the beginning of June for the 

 appearance of the imago, Von Eeichenau found the larvas at Mayence, still 

 unpupated, on pine-trunks with those of Canephora unicolor, in July, Hofmann 

 states that he has proved the species to pass two years in the larval stage by 

 breeding from eggs. 



