DISEASES AND PESTS 89 



which it burrows into the ground or forces its way 

 through woody tissues, The damage is done by the 

 adult. " A hole is made in the ground near the stem 

 of a young tree : those about two years old are usually 

 selected. Externally this opening looks like a crab- 

 hole — sometimes there is a heap of earth blocking the 

 entrance ; — either of these indications is a sure sign 

 that a beetle is at work. Generally one beetle only 

 is found, and it is sufficient to destroy a tree if not 

 removed in time." It may be killed or removed by 

 means of a wire. Lime around the young trees is an 

 effective preventive. It is suggested that some trees 

 be left unprotected as bait and watched. The larvae 

 live in rotten wood ; this stage lasts three to four years ; 

 the pupal stage lasts four to six weeks. 



Xylotrupes gideon, of which X. nimrod is sometimes 

 regarded as merely a form, is known well over the whole 

 Malay-Polynesian region, and is reported as a pest in 

 Java, the Philippines, and Solomon Islands. X. lorquini 

 is reported from New Guinea. These very large insects, 

 popularly known as " elephant beetles," are readily 

 recognized by the two huge projecting horns, one from 

 the head and one from the thorax, which reach forward 

 like a pair of curved tongs. In its attack on the coco- 

 nut the elephant beetle works in the same way as the 

 rhinoceros beetle, and is fought in the same manner, by 

 dragging the beetles out of their holes in the tree. 

 Froggatt reports that a related species of the same 

 genus collects on the jacaranda, an ornamental tree 

 common along streets in the tropics, and suggests that 

 this may accordingly be used as bait. There is a state- 

 ment in circulation to the effect that elephant beetles 

 do to palms more incidental damage with their horns 

 than they do directly in feeding or burrowing. It is 

 not easy to see how such an unwieldy insect does any 

 damage at all. 



Another related beetle reported by Froggatt is 

 Trichogomphus semilinki, Eitz., which he calls the 

 " Solomon Island rhinoceros beetle." In appearance it 



