xlii FAUNA HAWAIIENSIS 



were seen flying round the foliage, hardy insects which the ants cannot exterminate, 

 though they are often seen attached to them by the mandibles. Every tree trunk 

 was invaded by Pheidole, and beating the boughs dislodged them in thousands. 

 Not a single beetle nor any native insect was obtained from these trees. One 

 solitary tree, however, for some reason was quite free from ants. It was a large 

 Bobea, with hanging masses of ' Maile ' [Alyxia) dependent from the boughs. From 

 the dead stems of this were shaken hundreds, if not thousands, of one species of 

 Proterhinus, others also being present, as well as the large weevils, Rliyncogonus, 

 and other kinds of beetles. I visited this spot on many occasions for the sake of 

 a rare species of wasp, but never obtained a beetle except from this one tree, and 

 a year later it too was occupied by Pheidole and barren of native insects. Fortunately 

 Pheidole is not universal in its distribution. It can in some localities just attain 

 4000 ft. in the mountains, under certain climatic conditions. Below twelve or thirteen 

 hundred feet it often occupies most of the islands, excepting some extremely arid 

 localities. Though not so utterly destructive to other insects as to the beetles, yet 

 many of them are destroyed by it, and generally speaking, collecting is very poor, 

 where it abounds. Most of the native species taken in such places are vagrant, like 

 Lepidoptera, and have bred in some adjoining area, either free from this ant, or 

 where it is comparatively sparse. Miles of attractive forest in some parts of the 

 islands are almost devoid of native insects, through its destructiveness. A very few 

 endemic insects seem able to breed in its haunts, even where it is quite abundant, 

 but many of the foreign or imported insects flourish in spite of it. It is not probable 

 that it will spread to any great extent beyond the limits now occupied, for it has 

 long since filled all suitable localities. Here and there the opening up of limited 

 areas of forest may by change of conditions allow it to colonize these, but the great 

 bulk of the forest is now reserved and not likely to be opened up. There is no 

 reason to suppose that the endemic insect fauna will suffer any considerable further 

 diminution, and it may, so far as one can see, remain as it is for ages to come. 

 The chief danger would be in the introduction of some predaceous creature like 

 Pheidole, which would be able to occupy the great area of forest land and the country 

 above this, where Pheidole does not now exist. As no such insect has been imported 

 in the course of the last century, it is on the whole improbable that it ever will be. 



Comparison of 'introduced,' 'immigrant' and 'endemic' insects etc. 



In a memoir on the Hawaiian Coleoptera, published in 1885, by Blackburn and 

 Sharp, the beetles are divided into three classes : (i) 'introduced,' i.e. species imported 

 by man, (2) ' immigrant,' i.e. species occurring elsewhere, but which have reached the 

 islands by natural means, (3) 'autochthonous,' i.e. species peculiar to the islands, for 

 which I have used the older and more often employed term, 'endemic' 



