cxx FAUNA HAWAIIENSIS 



The former has been observed in enormous numbers, frequenting Vitex trifolia on 

 the sandy isthmus on Maui, the latter affects verbenaceous weeds on Oahu. The 

 forest-frequenting species are rather diverse in habits, some moving around freely in 

 the daytime, others resting at that time beneath bark, in moss, or amongst the foliage. 

 Many are gregarious or sub-gregarious, so that occasionally a number of examples may 

 be found resting side by side. Although many are more or less rare insects, there is 

 evidence that some of these occur in great numbers at times, or at least have been very 

 numerous, since in some localities we have found the soil full of the detached elytra, 

 when living examples were not to be found. Many of the species are very imperfectly 

 known, and in spite of their considerable size are not easily distinguished, being notably 

 variable both in superficial appearance, and in points of structure. Their headquarters 

 are apparently on Kauai and Oahu at the one extremity of the group ; none are known 

 from Hawaii at the other end and but few at present from Maui. There is no doubt 

 that many of the species are very local or restricted in range on the island that they 

 inhabit, so that many more species, or at least varieties of known forms, should be dis- 

 covered in the future. While some like the dense and wet forests, others inhabit very 

 dry localities, with scattered brush or small trees. Some of the species, such as the 

 well-known R. blackburni and koebelei, are known to be polyphagous, frequenting 

 various forest trees and even some species of ferns. The life-history of the former is 

 to some extent known and no doubt others will be found to resemble this in a general 

 way. The eggs are laid in numbers between two leaves of Acacia koa (and no doubt 

 of Straussia, Bobea, etc.) which are glued together. The young larvae on emergence 

 drop to the ground and no doubt feed on the decaying vegetable matter contained in 

 the soil. The eggs of R. blackburni are parasitized by the Chalcid, Eupehnus rhynco- 

 goni, one parasite emerging from each &gg. No doubt other and rarer species will be 

 found to have similar parasites, the number of eggs laid being out of all proportion to 

 the number of adult beetles that are found. On Kauai the scarce little thrush, 

 Phaeornis palmeri, is a most successful hunter of Rhyncogomis, for in all cases these 

 beetles were found in the bird's stomach, even to the exclusion of all other food, while 

 they have been found in no other bird. 



Pantomorus fulleri is an injurious beetle, imported, doubtless, with hot-house 

 plants from California. It was not known in Mr Blackburn's time. It first became 

 conspicuous on Maui, but it is now injurious on Hawaii, Oahu and Molokai. Of the 

 forest trees it is very partial to Acacia koa, the eggs being laid in masses in cracks of 

 the bark or in swellings caused by a Tortricid caterpillar. The young larvae fall to 

 the ground and feed in the soil, the habits being much like those of Rhy7icogonus. 

 The beede itself defoliates the rose, fruit-trees, and other plants, and in default of other 

 food it will attack young sugar cane. Being apterous, it could probably have been easily 

 controlled, if not exterminated, in the first period after its introduction. 



Cylas formicarius is another introduction, which still occasionally reaches the 



