THE LESSER CORN STALK-BORER. 19 
ACTIVITY OF THE LARVA. 
The larvae of this species, while very active, even when quite young, 
are much more so as they become older. They have a habit, when 
disturbed, of skipping and jumping about, an acrobatic feat which 
lasts from one to four seconds, during which time they go through all 
kinds of contortions, frequently throwing themselves clear of the 
surface upon which they have been placed. Just how this is accom- 
plished is not definitely known, as it is done almost too quickly for 
the eye to follow. However, they appear to bear down with the 
head and posterior end of the body at the same time, with such force 
that the impact throws them into the air. On account of this skip- 
ping habit the larvae are frequently but erroneously termed 
" skippers." 
That the larvae are resistant to rougn treatment is indicated by the 
following ordeal through which one was put by the junior author in 
an effort to photograph it. It was chloroformed for 15 minutes and, 
being then still somewhat active, was put into 80 per cent alcohol 
for 15 minutes more. The next morning it had revived and, except 
for a loss in the brillancy of its coloring due perhaps to its enforced 
fast, was as active as before. 
The larvae in all stages spin a silken thread wherever they go, and 
the younger ones readily suspend themselves by it. 
LENGTH OF PUPAL STAGE. 
The length of the pupal stage varies considerably, as will be seen 
from Table VII, temperature conditions having a great effect upon the 
length of this stage. This stage varies from 7 to 1 1 days in July, from 
7 to 10 days in August, from 8 to 18 days in September and October, 
and from 19 to 21 days in October and November. The general 
average from the records of Table VII is 10.16 + days. 
It should be stated that the records obtained during the fall of the 
year are approximate,, as it has been found that the larvae, upon 
entering the pupation tubes, sometimes do not transform immediately. 
