28 
feed in this way ratlier than in the usual one. Whether the ants do 
their teasing in the hope of inducing boll- worm fights, or only to drive 
out the larvae so as to have full possession of the ear, the fact remains 
that in either ease their actions are often responsible for the cannibal- 
ism which occurs among the Boll Worms in the ears. The ants seem 
to prefer the fresh juices of grains of corn yet in the milk to those 
found in the excrement of Boll Worms or the decaying grains which 
have previously been eaten into. In order to enjoy the freshest juices, 
however, they must first drive the Boll Worms from the point. It 
would seem, therefore, that the cannibalism in ears of corn due to the 
behavior of the ants is probably more incidental than intentional. The 
importance of their actions, however, is not to be underestimated. 
Their teasing process does not need to be repeated for each Boll Worm 
found in an ear. When a large Boll Worm is once thoroughly pro- 
voked in this manner it often goes to every part of the ear, and wher- 
ever another larva is found a fight ending in a dead Boll Worm is quite 
certain to follow. This may continue until only one remains, or it may 
go only to the extent of killing a few at that time. The slightest 
provocation within a reasonable time thereafter seems to be sufficient 
to start the exterminating process again. One such provocation by 
ants, therefore, often suffices to clear an ear of all Boll Worms but 
one. It should be borne in mind, however, that crowded conditions 
where the larvae encroach upon each other furnish the same provoca- 
tion for fighting. Cannibalism among Boll Worms, therefore, is not 
the result of a single agency, but of several, which directly or indirectly 
contribute to bring about the result. 
The large red wasp, Polistes rubiginosus, so common in cotton fields, 
carries off the larvae of many species found feeding upon cotton, and 
doubtless takes a Boll Worm occasionally when they are present. 
Polistes bellicosa, P. perplexus, P. gluerosa, P. annularis, Pompilus atra, 
P. americana, P. philadelphicus, Priocnemis fulvicornis, and Clialybion 
cceruleum, are all common in cotton fields, and doubtless capture Boll 
Worms, as well as other larvae. 
OTHER INSECTS. 
Other insects which are known to be carnivorous are often found 
abundant on t*,orn silks and infested plants. Notable examples on corn 
silks are Scymniis collar is and 8. cerviealis. These two species proba- 
bly puncture or eat into the Heliothis eggs found upon the silks. 
Two species of Robber Flies (Erax lateralis and Deromyia sp.), were 
observed catching Boll Worm moths on the wing. 
Metapodius femoratus is frequently found preying upon the Boll Worm. 
The young seem to be especially beneficial in this respect. Unfortu- 
nately the eggs of this species are attacked by an egg parasite which 
