ZOOGENESIS 



the caterpillars of several different kinds of butterflies 

 used to be, and in some places are still, in much 

 demand as food. Certain bats are very fond of butter- 

 flies, and mice and shrews eagerly devour them. 

 Some birds feed partly, and in the tropics largely, on 

 them. Certain small lizards and some of the smaller 

 snakes are very fond of them. Among their insect 

 enemies are mantes (fig. 19, p. 33), various preda- 

 cious bugs (fig. 2.3, p. 33), robber-flies, dragon-flies 

 (fig. 11, p. 33), hornets, ants, and the so-called cater- 

 pillar v^asps. 



But their worst and most destructive enemies are 

 various sorts of small wasp-like flies which lay their 

 eggs upon or in their eggs, their caterpillars, or their 

 chrysalids. The small maggots which hatch from 

 the minute eggs of these small parasites feed upon 

 the contents of the egg of the butterfly or upon the 

 juices of the caterpillars or upon the contents of the 

 chrysalids. Some of the true flies which in their 

 appearance are much like little blue-bottles also have 

 this parasitic habit. 



Many of the parasitic grubs which live unseen 

 within the bodies of the caterpillars have parasites 

 that feed on them. Although these live within the 

 caterpillars, they feed only on the parasites which 

 are themselves engaged in feeding on the caterpillars. 



And besides these enemies butterflies have many 

 more, for instance nematode worms (cf. fig. 81, p. 161), 

 bacteria and protozoans (cf. fig. 87, p. 161), spiders 

 and mites, sometimes even mosquitoes. Indeed so 

 numerous and varied are the enemies of the butterflies 



