LIFE-HISTORY OF ASTEROSCOPUS NUBECULOSUS. 59 
head is whitish. It now lives chiefly on the under side of the 
leaves, spinning itself there firmly; it eats the leaves from the 
edge inwards, and rests head downwards while feeding. If 
disturbed it raises itself, hke the larve of the Sphinges, 
and beats about with the upper part of its body; when touched 
it emits from its mouth a green transparent fluid, of bitter taste, 
resembling that of the birch leaves. After the first change the 
caterpillar devours the cast skin, which hangs like a white rag 
spun to the leaves. Until the second change it is usually 
remarkably lively and active, but less so as it becomes older, and 
the full-fed larva is sluggish and lethargic. It then sits with the 
upper part bent far forward, after the manner of the Sphinges, 
but always turned in a downward direction. When a large number 
are together in one cage they disagree, especially as they get 
older; they bite each other, and the wounded ones die in a few 
days. The birch (Betula alba) is their favourite food, but they 
will also eat buckthorn, hornbeam, elm, and guelder-rose. Before 
pupating the larva becomes restless, wandering all over the cage ; 
it eats little or nothing, and loses the beautiful green colour, 
becoming a dirty grey or brown; finally it buries itself about a 
foot deep in the earth. It lies there curled up, for twelve days, 
before turning to a chrysalis. 
Pupation takes place in the first half of June, and often lasts 
into the second year. I have opened pupe in June of the year 
following pupation, and found the moth perfectly developed and 
alive, though it would have stayed nine months longer in pupa. 
I have observed similar cases with Panolis (T'rachea) piniperda. 
The regular appearance of the perfect insect in March is very 
remarkable. According to observations in my diaries I have 
only twice found it in April: on April 4th, 1881, I took a male of 
a rich brown colour; and on April llth, of the same year, a 
crippled male on a hornbeam, by the flooded bank of the Mulde. 
The chrysalis had long been below high-water mark, but was not 
injured; water had interfered with emergence, however, and thus 
caused deformity. The pupa is very strongly made, and provided 
with two anal hooks, by the help of which the moth inside the case 
works its way up out of the earth. The appearance in March, 
1883, was most remarkable: in spite of the extreme cold 
(14° Fahrenheit), in spite of snow and hard frost, the pupa worked 
itself out of the warm ground, the moth burst its case, and, 
