
ð 
to climatic causes as the principal means that prevented the 
often observeđ, and very forcibly this summer, in the exam- *- 
. reported to the Academy ar] Natural Sciences, Philadelphia. 
. This same pue away of the pupa I have often noticed | 

94 INSECTS INJURIOUS TO THE POTATO. 
(Fig. 14, Coccinella 9-notata and pupa; fig. 15, Hippodamia 
13-punctata; a, larva; 6, pupa) without doubt destroyed 
some, but as I could not find them more numerous than usual, 
Fig. 14. I cannot admit that they were the chief means 
of this almost perfect extermination of potato 
6 ~ bugs. Moreover the larv: in June were suffi- 
ciently numerous, in propor- 
tion to the number of beetles 
A observed in the spring, and 
yet in July and August the beetles failed 
to appear as expected. We can only look 


The weather here was uncommonly hot as well as dry; 
hence the pups were exposed to the burning dry dust, and 
this doubtless was the efficient cause of the death of the soft, 
naked, delicate pups. The only object that they can have 
in entering the ground to transform, is protection from the 
hot dry atmosphere of summer and the cold frosts of winter, 
for they will transform well enough above ground in a paste- _ 
board box in a room, as I proved in hundreds of examples |. 
during the series of observations I made on the breeding of 
these insects in 1865, and reported in the “Practical Ento- 
mologist.” The ground usually furnishes a cool moist place; 
but this time it failed to favor them, hence they perished. 
I have often observed that the pups of various insects - 
perish from exposure to too much evaporation. The pup? 
of the various wood-borers however, carefully handled, will 
not develop so well in a paper box as in the hole they make - 
in the tree, and many of them dry away entirely ; this I have — 
-— 
l 
spring brood from maturing. | 
| 
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ples of the new species of beetle, that I have bred from b 
the prickly ash tree ; also the three varieties of beetles, bred — 
from the several borers, or “grubs,” found in the grape-vine, — 
