126 REPORT OF OFFICE OF EXPERIMENT STATIONS. 



Hawaiian Sug'ar Planters' Experiment Station, Honolulu. 

 C. F. EcKART, M. S., Director of Division of Agriculture and Chemistry. 



The most important entomological work of the year was the con- 

 tinuation of the attempt to introduce and establish the parasitic fly 

 which destroys the grubs of the cane borer throughout the Moluccas, 

 New Guinea, and other regions infested with this pest. The parasite 

 was actually introduced, and its breeding freely in captivity in Ha- 

 waiian borers has given promise of its establishment. Work in the 

 introduction of the horn-fly parasite, Bathymetis, was also continued, 

 but this insect has been found difficult to rear in confinement. Re- 

 ports were prepared on certain sugar-cane pests, the Angoumois 

 grain moth, the corn leaf-hopper, and the cotton-boll Gelechia, and 

 studies made of the cane leaf-roller and various flies as spreaders of 

 disease, especiall}'' typhoid fever. 



In the pathological work 22 distinct fungi were isolated from dis- 

 eased canes and grown in pure cultures. This work also included 

 similar studies of the diseases of pineapples, with which 9 distinct 

 fungi were found to be associated. Results of observations seem to 

 indicate that the fungus Thielaviopsis is responsible for all the more 

 serious diseases of j)ineapple plants, being apparentlv the direect 

 cause of the soft rot of the fruit, base rot of cuttings, and the decay 

 of many roots. It was demonstrated that even in its most resistant 

 forms this fungus is killed within a few hours by exposure to direct 

 rays of the sun. Attention was also given to diseases of leginninous 

 plants and to the cane disease known as iliau. It was found that iliau 

 is caused by a parasite fungus, a new and undescribed species of Mel- 

 anconium. A study was also made of a serious cane disease prevail- 

 ing in the Fiji Islands. A considerable amount of inspection work 

 was also performed. 



The forestry Avork of the station included experimental planting of 

 tree seeds on a small scale at Kailua, Maui. Arrangements have 

 been made to obtain seeds for this work from British East Africa, 

 Mauritius, the Philippines, West Indies, and the southern United 

 States. 



The department of chemistry and sugar technology made a total 

 of 3,107 analyses during the year and published the results from re- 

 search investigations in six different bulletins. The different prob- 

 lems studied in this connection were the influence of the structure 

 of cane on mill work in sugar factories, the determination of sucrose 

 in molasses, the composition of bagasse with special reference to 

 sugar and moisture, sulphate scales in evaporators and their preven- 

 tion, biochemical processes in Hawaiian soils, and the inversion of 

 cane sugar under the influence of acids and neutral salts. A series 

 of lysimeter experiments were started with two different types of soil 



