ENTOMOLOGY 229 



a serious circumstance, since the growth of the sprouts is supported 

 by the stalk, and unless the cane is soon cut and ground the stalk is 

 rendered worthless. 



The first injury to the cane plant by the leaf hopper occurs 

 through the piercing of the epidermal layer by the ovipositor. 

 Through these wounds various diseases may also gam entrance to the 

 tissues of fhe plant, carried thereto by the leafhoppers themselves in 

 flying from infested to noninfested plants, or by other insects, par- 

 ticularly certain flies, which frequent the cane plant. The most 

 serious injury to the plant is the drain upon its vitality caused by 

 the young leafhoppers in feeding. The thorough burning of the 

 trash after the cane is harvested is the most effective method prac- 

 ticed for the control of the insects of sugar cane. In the case of the 

 leafhopper many of the adults no doubt take flight, but the destruc- 

 tion to the eggs and immature forms in the trash is enormous. Both 

 for the leafhopper and the cane borer, burning off has become gen- 

 eral once more. Rotation of crops will be of great benefit. 



The Hawaiian Sugar-Cane Borer. The sugar-cane borer infest- 

 ing the cane stalk in Hawaii is the grub of a beetle belonging to the 

 weevil family Calandridse. The sugar-cane stalk-borer of the south- 

 ern United States is the caterpillar of a moth. Entomologically the 

 two species are widely separated, belonging to entirely different or- 

 ders of insects, but in the character of their injury to the cane stalk 

 these two insects are quite similar that is, they both develop within 

 the cane stalk, and by feeding on the interior cause great destruction 

 to the plant. Comparatively, the Hawaiian borer is more destructive 

 and, because of the habits of the adult, a more persistent species to 

 combat. The adult beetle of the Hawaiian borer is a stronger flyer 

 than the adult moth of the mainland borer and therefore has a wider 

 range over any infested territory. As the adult of the Hawaiian 

 borer, too, can emerge from any reasonable depth when buried in 

 the soil, this renders the question of infested seed cane a serious one 

 in Hawaii, while on the mainland the careful covering of infested 

 seed cane is effective in preventing the emergence of the adult moth. 

 These points are mentioned to bring out the fact that we are dis- 

 cussing here a species in no way related to the cane borer of the 

 Southern States and in many ways not subject to the same means of 

 control. 



The eggs are found beneath the epidermis of the cane stalk, or 

 more rarely in the tissue of the leaf sheath, having been placed singly 

 in small cavities. The cavity is made by the female with her pro- 

 boscis before depositing the egg. The young grub or larva, on hatch- 

 ing from the egg, bores on into the stalk of the cane, completely 

 honeycombing the interior with tunnels running lengthwise with 

 the stalk. The evidence of its work is not indicated by the outward 

 appearance of the stalk. Many times a stalk, seemingly in a normal 

 condition, is found on examination to be utterly destroyed. The 

 life of the borer within the stalk of the cane is esti mated to be about 

 seven weeks by Mr. Koebele, who points out the fact that the length 

 of the larval life depends to a great extent upon the condition of the 



