58 TIIK ENTOMOLOGIST. 



NOTES ON EEAEING MACROTHYLACIA (BOMBYX) EUBL 

 By L. W. Newman, F.E.S. 



HAviNa reared a quantity of M. ruhi during the winter and 

 noted some remarkable incidents in the process I have pleasure 

 to place same on record. 



During September, 1916, I collected some 300 wild larvae ; 

 these were fed till hibernation on sallow {Salix caprea). In 

 October, when all had finished feeding, large sleeves were placed 

 over common laurel bushes ; any other tree or bush would do, 

 but laurel is less likely to make boles in sleeve during winter. 

 About one foot of tightly packed moss was placed in the 

 sleeves and the bottom of sleeves kej^t off the ground so tbat a. 

 current of air could get under, and all round, of course, these 

 sleeves were right out in the open in a sunny place exposed to 

 all weather. 



During the frost in mid-January all were turned out and 

 larvae collected ; several large glass and zinc-breeding cages 

 were filled with wet moss about 10 inches deep, the larvae placed 

 in them, and tbe cages stood on the mantelpiece just over my 

 anthracite stove which is always burning night and day and, 

 kept well on, produced a temperature inside the cages of about 

 70° F. Daily tbe moss in tbe cages was well sprayed with 

 WARM water; in about an hour the frozen larvae started to wake 

 up and were soon crawling about. I noticed on the second 

 day several had started to spin cocoons. After fourteen days I 

 turned out the cages, and to my great surprise found that fully 

 60 per cent, of tbe larvae were curled up low down in the moss 

 fast asleep, and that in a temperature of well over 70° F., for 

 low down in the wet moss it was much hotter than on the top. 

 I found about 10 per cent, of dead larvae and 40 per cent, of fine 

 healthy pupae, or larvae in cocoons just about to turn. I now 

 decided to try a bold experiment. I filled one of the cages to 

 the top with damp moss and placed the larvae in it ; I then 

 took it from my warm room and placed it on the hard frozen 

 lawn amid snow and left it there all night ; there was a very 

 hard frost, and in the morning the cage was frozen to the 

 ground and the contents a solid mass of ice. I made my stove 

 very hot and got up a temperature of well over 80*^ F., and brought 

 in the cage and stood it over the stove ; in a short time it was 

 enveloped in steam as the moss thawed, but I saw no movement 

 of the larvae for some time. After about three hours I saw a few 

 crawling about, and later a good many. Next day I could see 

 several forming their cocoons, so hoped all was well. In a week 

 I was anxious to see what had happened, so very carefully turned 

 out the cage. I found similar results as before ; a few were 

 dead, a nice lot of lively pupae and larvae in cocoons about to- 

 pupate, and other larvae curled up asleep as before. 



