VI. 



Cannibalism amono" Insects.' 



IT is known that the caterpillars and larvae 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 Calymnia tmpezina,^ Agrotis 

 ypsilon, Heliothis armiger, 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 Aiuiles de la Socicdad Cientifica Argentina, Nov., 1892, 

 pp 236-238. 



- 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 larvae of Cheimatobia hrumata. — Ed. 



