130 



Supplementary Notes on Rhyncogonus blaekburni and Its 

 Parasites. 



BY R. C. L. PEEKINS. 



(With figure) 



In the Animal Address to this Society for the year 1905, 

 after giving an account of the insects inhabiting a portion of 

 the mountains near Honolulu, in some concluding remarks I 

 observed that "to know the life-history of Rhyncogonus hlack- 

 buimi and why it remains so comparatively weak in individuals, 

 or to fully ascertain the life-history of some of the Carabids, 

 and why again some are so common, others so extremely rare, 

 would be far more interesting than the discovery of half a 

 dozen new Proterhmus which would surely differ but little 

 from species already known." From Mr. Giffard's interesting 

 paper just read, it will be seen that the desired information as 

 to the Rhyncogonus is now largely supplied. 



The distribution on Oahu of Rhyncogonus hluchhurni is not 

 exactly known, but it is almost certainly absent from the 

 Northern third of the long Koolau range, which has been much 

 collected over, and it is probably absent from the middle third 

 also. It has never been taken, in fact, on any part of the 

 range north of Nuuanu Valley, which very possibly limits its 

 distribution. It occurs throughout the mountains south of 

 !N"uuanu, wherever they have been investigated, but only at 

 certain elevations being absent from the higher and wetter 

 portions of the range. It is partial to many other trees besides 

 Acaciu Jcoa, such as Straussia, Ewphorbin, etc., and is even 

 found on ferns such as Gleichenia dichotoma. It is absent 

 from, or at least has never been found in the Waianae range 

 of mountains. In its own limits it is overlapped by R. koehelei 

 and possibly other species, and outside the limits it is replaced 

 by several other forms at present undetennined. It is rather 

 of a social nature (being like other Rhyncogonus in this re- 

 spect) so that not infrequently four or five individuals will 

 be found in company, sometimes even closely packed together, 

 when at rest, and the sexes are usually in coitu. In beating 

 trees, it is often found singly, but this is no doubt due to the 

 fact that some fall clear of the beating cloth or umbrella, and 

 consequently are not noticed. 



The large size of the beetles (as compared with most nativ^e 

 Coleoptera) and their extreme tenacity of life under almost any 



