1897.] Mr Perkins, Notes on some Hawaiian Insects. 379 



colours '. That these markings have any such significance is I 

 think certainly not the case. There is no reason to suppose that 

 the species on Kauai have any more need of their special 

 coloration than the black species of Hawaii, but rather the 

 reverse, as birds, which are their only possible enemies, are more 

 numerous on the latter island. As a matter of fact, after the 

 examination of the food of many individuals of nearly all the 

 endemic birds, I have never found them to feed on any of these 

 insects whether black or coloured, nor would the majority of them 

 be the least likely to do so, on account of their habits and 

 structure. For the most remarkable feature exhibited by the 

 endemic land-birds is the specialization of form for the purpose of 

 securing some special food, which has led to the extreme diversity 

 of structure exhibited in a group so small as the Drepanididae. 

 So extreme is this specialization of some of the birds, that their 

 food is almost limited to one special form of plant or animal, as 

 we have already seen in the case of Pseudonestor; while even in 

 less specialized birds the range of food is very small. It is just these 

 most highly specialized birds that are the first to disappear when 

 their natural surroundings are interfered with, as they have already 

 done on the Island of Oahu, which has been more upset than the 

 rest of the group, by foreign settlers. It is not exaggerating to 

 say that the extinction of a few species of beetles would extermi- 

 nate both Pseudonestor, and the various species of Heterorhynchus, 

 while the disappearance of three species of trees would do the 

 same for the three genera Rhodacanthis, Chloridops, and Lox- 

 ioides, and many of the other birds are equally dependent on a 

 particular section of either fauna or flora. 



The birds most likely to feed on the Odyneri are the fly- 

 catchers of the genus Chasiempis, which do not appear to do so, 

 but confine their attention for the most part to small Lepidoptera 

 and their larvae. If they did feed on these, one would expect the 

 Odyneri of Hawaii to have distinctive marks as well as those of 

 Kauai, since the birds are equally common upon both. But there 

 is every reason to believe that the colours of the insects have no 

 such significance, and it is still further convincing to notice that 

 the Odyneri of Molokai have a general tendency to red-markings — 

 Molokai being an island where no fly-catchers exist, — while on 

 Hawaii these insects, even in certain points of structure of 

 secondary value, tend to greatly resemble each other. 



The distinct style of coloration of the Kauai species is a point 

 of some importance, for it has long been known that in other 

 countries insects of this group have a great general resemblance 

 to one another in the country they inhabit, as for instance the 

 highly endemic species in Australia and Chili. No doubt, were 

 they more widely known, these cases of Chilian and Australian 

 VOL. IX. PT. VII. 31 



