THEIR RELATION TO EACH OTHER 119 



positors four or five inches long. Very often, especially 

 among the smaller species, the colors are brilliantly 

 metallic, and they range all the way from smoothly 

 shining to deeply pitted as to surface. 



There is no species so small and none so well con- 

 cealed in feeding as to save it from parasites, and 

 these latter may infest any stage from the egg to the 

 adult. It is not unusual to find a batch of "bug" 

 (Hemipterous) eggs and to hatch from them a brood of 

 minute wasps instead of the little bugs that were ex- 

 pected. And when a lot of pupae or chrysalids have 



FIG. 58. Aphelinus, parasite on armored scales. 



been collected, the result may be butterflies or moths, 

 but is just as likely to be several hundred or only a 

 few parasites instead. The size of the chrysalis is 

 no indication of the number of parasites to be expected. 

 Out of a large Papilio or swallow-tail we may get a 

 single large Trogus and out of a small Pieris or cabbage 

 butterfly we may get one hundred or more little bronze 

 Chalcids. On a twig infested by scales one may often 

 see a large percentage with little round holes through 

 the shell proof positive that from each a minute 

 little wasp has issued; and on a. leaf infested by plant 

 lice, we often see some that are abnormally swollen or 

 rounded and tending to turn gray. These also are 

 parasitized and will shortly show a nice little round 



