88 
HALF HOURS WITH INSECTS. [Packakd. 
required as they approached maturity, to fresh food and 
cleansed quarters. With proper care, the thumb and fingers 
could safely 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 by Pro¬ 
fessor Winchell to be never eaten by 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 Society, 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 acrcea) and the caterpillar of the vaporer moth 
(Orgyia) and the spring larvae of butterflies; with these 
may perhaps be classed the European currant saw-fly. He 
24 
