VI. 
Cannibalism among Insects." 
T is known that the caterpillars and larve of lepidoptera, crickets, 
and locusts feed on plants, of which they consume great quan- 
tities, in order to reach their full development or to prolong the 
imago condition, and to fulfil their mission of propagating the 
species. 
Notwithstanding the vegetarianism of the insects mentioned, 
cases are known in which they abandon their usual habits and 
become addicted to a flesh diet, and, what is still more strange, they 
feed upon their own kind. 
The larvicide instincts of the caterpillars of certain moths 
have been known for a long time, the cannibalism having been 
observed in various species deprived of their liberty, and brought up 
in confinement, either with or without vegetable food. Thus, for 
example, the caterpillars of the moths Calymmnia trapezina,? Agrotis 
ypsilon, Heliothis armigey, and others, finding themselves in captivity, 
abandon their vegetable regimen and devour their companions, 
whether out of disgust at finding themselves imprisoned, or for want 
of fresh vegetable food, or for other causes of which we are ignorant. 
In any case, after the development of the disordered appetite, the 
caterpillars do not any longer care for vegetable aliment, and they 
endeavour to satisfy, in any way, their newly-acquired carnivorous 
habit. Out of a number of caterpillars associated together, of the 
above-named species, finally only one remains, which in the savage 
warfare, either by its strength or subtlety, has succeeded in saving 
itself, devouring the last of its companions which placed its existence 
in danger. 
What has been just said only relates to caterpillars in captivity. 
So much greater is the fact which I discovered, that in the free con- 
dition there also exists cannibalistic larvicide. During my voyage in 
Southern Patagonia, in 1874, I noticed that the cannibalistic instinct 
was very prominent in the caterpillars of the district, whether free or 
imprisoned. 
1 Translated from the Annales de la Sociedad Cientifica Argentina, Nov., 1892, 
pp. 236-238. 
2 The caterpillars of this moth are said to be often carnivorous in the wild 
state, and to render considerable service to fruit-growers by devouring the de- 
structive larvz of Cheimatobia brumata.—Eb. 
