416 NATURAL HISTORY OF HAWAII. 



wood, stems and bark of trees, on the leaves, flowers, and in the seeds of 

 plants, in moss, in fnn^i, in fern stems — in fact, a thousand possible places are 

 all liable to be inhabited by some rare and interesting beetle. 



That many species, especially among the long list of those introduced since 

 commerce was established with Hawaii, are injurious to man and to his inter- 

 ests, has been touched upon in a former chapter. That many forms work to 

 man's economic benefit has also been hinted at. Of most of the peculiar native 

 species little is really known of the place they occupy in the economy of nature. 



The larvff", commonly called grubs, seldom display conspicuous character- 

 istics, and exhibit nothing to indicate the diversity of form assumed by the 

 adults. They are mostly dingy -white, brownish or occasionally even black in 

 color. The head is always horny and usually provided with jaws suited to bit- 

 ing and grinding their food. The pupa stage follows the larva and varies 

 greatly in length of time. Whether it is passed in a cocoon or not, the embryo 

 beetle lies inactive with the appendages all plainly shown, each enveloped in 

 its own peculiar covering. From this they emerge in due time to take up the 

 active life of the adult. 



Passing to a consideration of a few of the more interesting or more 

 important families, we find that of the great division knoAvn as the predaceous 

 beetles, the ground beetles,-^ with legs suited to running and with thread-like, 

 tapering antenna^, are represented by more than two hundred small species, 

 many of them belonging to genera peculiar to the islands. They vary greatly 

 as to habits, the most of them, however, undoubtedly feeding on insects. They 

 are found under stones, beneath dead wood, in moss, in trees, under bark, at 

 the base of leaves and on the ground, scurrying about. Two small species of 

 predaceous diving-beetles-- belonging to this division, but to diiferent genera, 

 occur in fresh water all over the group ; they appear to be nowhere abundant. 



The diving-beetles can be distinguished at once from the six species of 

 water scavenger-beetles,^^ some of which occur in pools and I'unning water, 

 and some in rotten wood and decaying vegetation. The water scavenger- 

 beetles all have club-shaped antenna? (which are often concealed beneath the 

 head) and very long palpi. As a matter of fact, these aquatic scavenger- 

 beetles belong to the extensive division of the beetle order known as clavicorn 

 beetles, in which the antenna^ are club-shaped — that is, they grow gradually 

 thicker towards the top. Hawaii has twenty oi- more families belonging to this 

 group, including such v/ell-known families as the carrion-beetles,--^ with but a 

 single introduced species so far found : and the rove-beetles,--"^ with upwards 

 of one hundred species. They may all be faii'ly well recognized by their short 

 wings and long, narrow abdomen. They are mostly carnivorous, and rove 

 about in search of food. Insects constitute a large part of their food, espe- 

 cially insect larva\ but many feed on rotton wood, some on fungi and others on 

 flowers. 



The twenty species of small hemispherical lady-bugs, or ladybird beetles,-" 



21 Carabidw. -- Dytiscidcv. -^ Hydrophilidcp. -* ,Silphid(V. "" Stiiiilii/tiuidce. -'^ Corrinfllidd-. 



