Packard.] THE POPULATION OP AN APPLE TREE. 187 
wing is a black oval spot. The caterpillar I have not de¬ 
tected. It is described, however, by Dr. Clemens as being 
dark yellowish green, tinged with reddish in front, with a 
brown head. It was found feeding externally on the leaves, 
late in September. Early in October it changes to a chrysa¬ 
lis within a long white cocoon, slenderer, but about as long 
as a grain of rice; it is tough and thick, and ribbed exter¬ 
nally. It is a common object, found attached to the bark 
of the tree in May as well as the autumn and winter. These 
little moths are not exempt from parasitic ichneumons of 
exceeding minuteness, which send them to an early grave. 
Indeed the mortality among moths is greatest during their 
childhood, when they are in the chrysalis state. While a 
few caterpillars, like very many hu- fig. 140. 
man children, die of over-eating, the 
greater number of deaths are due to 
causes beyond the control of the cat¬ 
erpillar. In Europe, twelve hundred 
species of minute, chalcid ichneumon 
flies are known to exist, and of these 
many prey on the Tineids. I have 
found a most singular form preying 
on the Bucculatrix of the cedar ( B . 
thuiella , Fig. 140, enlarged; a, co- 
. . . N t • -u i i Bucculating thuiella. 
coon, natural size), which closely 
resembles the apple moth. In endeavoring to rear the moth 
from the cocoon I found that nearly half of the cocoons 
gathered from a cedar tree in my yard, failed to give out 
their appropriate tenant, but instead, rendered account in 
the form of minute beautifully brilliant green flies, with 
golden metallic tints. The antennae branched out like the 
antlers of a reindeer, each having at the end five branches, 
somewhat resembling a Japanese comb. These little flies 
are worth far more than their weight in gold, and were their 
worth duly appreciated our gardeners would look upon the 
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