208 



Fig. 6 



be considered of any economic ini])ortance. I'ig. 6 is a repre- 

 sentation of a very minute beetle, about one-eighth of an inch in 

 length, much magnified. This borer (.rylcbonts pubcsccns) be- 

 longs to a family notorious throughout the world, but especially 

 in colder countries, for the injury that is done by its members 

 not only to forest, but also to sliade and fruit trees. To the 

 same genus belong's the so-called "shot-borer" of the cane fields 

 in the West Indian Islands. There are man}- species of these 

 "shot-borers" in the forests, most of them being indigenous and 

 apparently doing no harm, since they only attack very unhealthy 

 trees, while others like the one figured attack trees, which, if not 

 perfectly healthy, at least would be likely to recover, but for the 

 borers. On one occasion a forest fire in the mountains of the 

 Waialua district of Oahu slightly scorched many larp;e Koa 

 trees, which would almost certainly have recovered had they not 

 been attacked by this common shot-borer, which rapidly increased 

 to many millions in the area of the fire. On another occasion the 

 Halape])e trees, once numerous in Nuuanu valley, were attacked 

 by another species, almost every tree being riddled with its bor- 

 ings and many trees were killed outright. Closely allied to the 

 shot-borers arc other still more minute beetles ( Hypothcncmus) 

 which are occasionally injurious in the lower forest, and one of 

 the species is notorious from the fact that it attacks the alligator 

 pear trees and becomes very numerous. It is questionable, how- 

 ever, whether the trees, so attacked, have not first become dis- 

 eased. The .smallest s])ecies of all (H. cntditus) is not only num- 

 erous in the lower forests and on the lowlands, but sometimes is 

 found in houses, boring into the covers of books or other mate- 

 rial. This species is occasionally attacked by a very minute para- 

 site, but, generally speaking, all tlu"^e small borer- are free from 

 jjarasites. 



Very similar to the shot-borers, but rather larger than most of 

 the.se, is another borer (Crossotiirsus cxfcnicdciitatus) which is 

 also found very numerously in alligator pear trees, often in com- 

 pany with the former. It is easily recognized by the different 

 structure of the legs and the remarkable form of the wing cases. 



