80 
b}^ ants or other insects, but this does not seem probable. It seems 
to be simply an inherent instinct. The bollworms appear to relish the 
bodies of their unfortunate fellows, but soon sicken and die if com- 
pelled to subsist for a long- time on this sort of food. Several were 
experimented on in the laboratory b}^ feeding them on crushed cater- 
pillars, but none so fed matured successfully. 
This is one of the most valuable factors in reducing the injmy to 
corn, for if all the larvae in an ear should feed peaceably together, as 
is usual among many other species of caterpillars, the}^ would no 
doubt often consume it entirely. This would mean, in certain regions, 
an almost complete destruction of the corn crop. During August, 
1904, an actual count was made of a number of corn ears to ascei'tain 
the number of larvae present. In 10 ears there were in all 168 larvae, 
each containing from 8 to 38 in all stages of development, although 
mostly quite small. This is an average of nearly 17 to an ear, or over 
eight times the number which could eventualh" mature. 
Cannibalism is not so important in lessening injury" to cotton, since 
the larvae are more isolated and do not meet one another so often. 
During seasons of bad bollworm injury, however, it may be an appre- 
ciable factor in their reduction. 
Aside from eating larva3 and pupae of its own species, the larger 
bollworms will often feed extensively upon the larvae and pup^ of the 
cotton caterpillar late in the fall when the latter is abundant, as well as 
upon other species. 
LEAVING THE PLANT AND ENTERING THE GROUND FOR PUPATION. 
Bollworms feeding in ears of corn enter as very small larvae, as 
alread}^ described, by eating down through the silks and between the 
shucks at the tip of the ear. When they are completely grown no 
opening for exit is present, and the larva must either eat its wa}" out 
in the direction it entered or bore directly through the shuck near the 
tip. This last_is the way usually chosen, and after the larva has 
emerged, a more or less sharply cut hole of the diameter of its body 
is left through the shuck. Only a ver}^ few crawl out through" the 
silks, most probably because the latter are almost always decayed and 
mold}^ at this time. We were never so fortunate as to see a larva in 
the very act of leaving the corn ear, which would suggest that this 
most probably occurs at some time during the night. Whether the 
larva crawls down the stalk or drops directly from the ear to the 
ground was not determined. Comstock (Rept. Cotton Ins. , 1879, p. 307) 
believed that the}^ drop directly from the ear. What evidence this 
assertion is based upon is not given, and, to judge fiom the usual 
cautious actions of the larva when crawling about, it w )uld seem very 
doubtful that they should do so. In a single instanr ., on August 4, 
