88 HALF HOURS WITH IXSECTS. [PACicAno. 



required as they approaelied maturity, to fresh food and 

 cleansed quarters. With proper care, the thumb and fingers 

 could safelj^ be passed along their sides and beneath them, 

 slowly raising them from the leaf or stem to which they were 

 attached ; but if attempted too hastily the larva throws it- 

 self in a circle, projects its defensive armor, and inflicts a 

 sting which effectually releases it from the grasp." 



Now while nature has protected these caterpillars from 

 their insect enemies, though certain ichneumon flies prey 

 upon them, they seem, whether by reason of their spiny hairs 

 or stiff bristles or other cause, to be distasteful to birds. 

 We are not aware how different are the tastes of birds for 

 different food ; as with us so with birds — de gustibus non dis- 

 putandum. We observe how different and arbitrary are the 

 tastes of the dog or horse or cat ; so wild animals, including 

 birds, have their individual preferences and dislikes for cer- 

 tain kinds of food. Certain it is that there are many kinds 

 of caterpillars which birds will not eat. The false cater- 

 pillar of the cherry sawfly (Selandria cerasi) is said b}- Pro- 

 fessor Winchell to be never eaten b}^ birds. The currant saw- 

 fly worm, now so destructive in our gardens, is not eaten by 

 birds. In my "First Annual Report on the Injurious and 

 Beneficial Insects of Massachusetts, 1871," occur the follow 

 ing remarks on this point. "As this is an important and 

 practical subject, let us digress for a moment, to notice 

 some facts brought out by Mr. J. J. Weir, of the London 

 Entomological Societ}^ on the insects that seem distasteful 

 to birds. He finds, by caging up birds whose food is of a 

 mixed character (purely insect-eating birds could not be 

 kept alive in confinement), that all hairy caterpillars were 

 uniformly uneaten ; such caterpillars are the "yellow bears" 

 (Arctia and Spilosoma), the salt-marsh caterpillars {Leu- 

 carctia acraca) and the caterpillar of the vaporer moth 

 (Orgyia) and the spring lai-vre of butterflies ; with these 

 may perhaps be classed the European currant saw-fly. He 



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