438 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 6 



some distance up the other side. The beetle has also very recently 

 appeared in limited numbers in the island of Savaii where it has 

 probably been carried by the natives who are constantly passing back 

 and forth, carrying quantities of mats, food and many other articles 

 in which the beetles and larvae or eggs might easily be transported. 



In districts where infestation is the worst, hundreds of trees are 

 being killed on many of the plantations and others are being so badly 

 injured that, even should they recover, it will be some years before 

 they will have a good crop of nuts. 



As the beetles attack the most vital part of the tree, the succulent 

 crown, one or two will quickly kill a young tree. Older trees are 

 able to sustain greater loss but even a few beetles in them will soon 

 make them unproductive, and, as the trees are sometimes attacked 

 by as many as ten or fifteen beetles at once, even the sturdiest trees 

 may succumb. The beetles usually attack the tree close to the base 

 of some of the leaves, between the base of a leaf and the tree, or between 

 the bases of two leaves. They are thus enabled to use their legs to 

 brace themselves firmly while beginning their burrow. The strong 

 curved horn on the head is also called into use as the beetles gnaw 

 their way through the tough fiber. The head is lowered and the 

 horn thrust into the fiber, then as the head is raised the body is drawn 

 forward. As the beetles are usually an inch and a half long and 

 about an inch in diameter the holes that they make in the base of 

 the larger leaves are very conspicuous, particularly as the older leaves 

 die and hang down. On their way toward the center of the plant 

 the beetles usually cut through some of the young leaves, the pinnae 

 of which are still folded closely along the midrib. As these leaves 

 unfold they present a very characteristic appearance looking as if 

 they had been cut by shears. Having reached the tender heart of 

 the tree the beetles feed on it probably for some weeks, often destroy- 

 ' ing much or all of it, thus killing the tree. 



The beetles swallow but little or none of the fiber through which 

 they bore. A study of their mouthparts shows that they are less 

 fitted for biting and chewing than they are for boring and tearing 

 and crushing. The inner surfaces of the heavy mandibles do not 

 meet except at the extreme base, the triangular space between them 

 being filled by the maxillae and the tip of the labium. The outer 

 margins of the maxillae and the labium are furnished with a dense 

 fringe of rather long stiff bristles which, with similar bristles on the 

 labrum, serve as a sieve for straining out the particles of plant tissue 

 that are torn loose by the mandibles and the two tooth-like projections 

 above them. The mandibles and their projections tear the tissue 

 of the plant into shreds and the juice which is crushed from it is strained 



