THE ENTOMOLOGIST’S WEEKLY INTELLIGENCER. 
95 
hybernating larvae. 
To the Editor of the * Intelligencer ' 
Sir, — The following account of an 
expei'inrient in rearing Lasiocampa Rubi 
may perhaps interest some of your readers, 
more especially as I believe the same 
plan may be adopted with other hyber- 
nating larvae with equal success. The 
difficulty of keeping these larvae in a 
healthy state through the winter has fre- 
quently been noticed, and various ways 
suggested for assimilating the conditions 
under which they are kept in confinement 
to those under which they would have 
passed the winter, had they been able to 
choose their own domicile. In all these, 
60 far as I know, success has been very 
variable and uncertain. 
These failures are, I believe, prineipally, 
if not entirely, owing to imperfect hyber- 
nation ; and last autumn the idea oc- 
curred to me, that when a caterpillar was 
once rendered torpid by the reduction of 
the temperature to near the freezing 
point, he might, if that temperature were 
uniformly maintained, be kept the whole 
winter without injury, and be resuscitated 
at pleasure when spring returned. 
To test this theory by practice, I last 
October procured twelve full-grown larvae 
of L. Rubi, and placed them in a wooden 
box about eight inches square, three parts 
filled with dead leaves, and perforated 
by a number of small holes for the purpose 
of ventilation. The lid was screwed down 
and the box hung up in an ice-house, 
the temperature of which would average 
a degree or two below 32°. There it 
remained undisturbed till the middle of 
March in this year. Some of my ento- 
mological friends whom I told of the 
experiment shook their heads and signifi- 
cantly asked, whether I had put all my 
larvfe into the same box. Notwith- 
standing their gloomy predictions, upon 
opening the box all the larva; were alive 
and apparently well. I placed them, 
with the leaves they had been among, in 
a breeding cage in a window with a south 
aspect, and every day when the weather 
was bright some of them came up and 
sunned themselves, but did not eat any 
of the fresh food with which they were 
supplied. During the latter half of 
April they all spun cocoons, but only 
eight passed into the pupa state, four 
dying without being able to cast off 
entirely their old skins. Of the eight 
healthy ones, five proved to be males and 
three females, the first moth (a male) 
coming out upon the 22nd of May. 
A single experiment of this kind is 
not, perhaps of much value, but the fair 
share of success that has attended it will, 
I hope, induce others to repeat it. 
The plan, I believe, is correct in 
principle, but, doubtless, improvements 
may be suggested in the mode of carrying 
it out. 
Yours, &c., 
Thomas Ransome 
Hest Bank, near Lancaster. 
June 6. 
PS. Since writing the above I have 
seen one of the incredulous friends before 
alluded to, and find that out of twenty 
larvge collected at the same time and 
place as mine, and kept among dry leaves 
in an outhouse during the winter, though 
all lived till spring, they became thin and 
emaciated and not one had strength to 
change into the chrysalis state. — T. R. 
A slight Mistake . — Please explain in 
the next number of the ‘Intelligencer’ 
that in having my name inserted in the 
‘ Annual ’ list as “ a collector for sale,” 
