58 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 85 



hairy than these are those of the gipsy and the brown-tailed moths ; 

 the hairs of the latter species especially cause a troublesome and 

 painful rash upon the skin of man. Nevertheless 46 kinds of birds 

 are known to eat caterpillars of the former species and 31 those of the 

 latter. (For a valuable article on bird enemies of these and other hairy 

 caterpillars, see Forbush, E. H., Bull. 20, n. s., U. S. Div. Ent., 

 pp. 85-93, 1899.) 



The larvae of the tussock moth (Orgyia Icucostigma) are supposed 

 to be especially distasteful to birds, but Forbush records (Mass. Crop 

 Rep., July, 1900, p. 36) nine species of birds as feeding upon them. 

 The writer dias observed English sparrows and robins eating them ; 

 in the spring of 1921 in Washington, D. C, the larvae were quite 

 common and robins were feeding freely upon them, carrying them 

 to their young, I believe, as it was a common sight to see the birds 

 frying with the white tufts showing at the tips of their bills. 



Again records of birds feeding on fall webworms (Hyphantria 

 textor) are relatively scanty, only six species being named, yet careful 

 observation in the field has proved one of them to be a very effective 

 foe. Dr. C. Gordon Hewitt informs us that of the various factors 

 operating in the reduction of this insect in Nova Scotia in 1916, the 

 red-eyed vireo was most important and " it was estimated that about 

 40 per cent of the larvae had been destroyed in the webs by this bird." 

 (Rep. Dominion Ent. 1917, p. 8.) A later report shows an average 

 destruction of 68 per cent. 



It would not be necessary to refer to the preying of birds upon 

 smooth caterpillars, a thing universally done, except for theoretical dis- 

 quisitions as to the " protected nature " of certain groups. The 

 Geometridae, loopers or measuring worms, are said to be protected by 

 resemblance to twigs, etc., a statement made without giving due weight 

 to the fact that such a defense depends upon immobility whereas these 

 caterpillars must be in motion the greater part of the time while 

 searching for and devouring food. Forty-four species of birds are 

 recorded as feeding upon Geometridae in our tabulation and numbers 

 of specimens as high as 20 were taken at one meal by the starling and 

 90 by the robin. 



Larvae of the Sphingidae are said to be protected by their " horns " 

 and by " terrifying attitudes," but 44 species of birds covered by the 

 present investigation do not seem to agree with the theorists on these 

 points. Ten species are known to prey upon Dlelephlla lineata alone, 

 and in field observation the crow has been known to clear tomato 

 patches of the hornworm {Phlcgethontius sexta). 



