DIVISION OF ENTOMOLOGY. 31 



in the summer of 1899 to advise with tlie plantation owners as to the 

 best remedial work. This work was carried on to some extent during 

 the fall of 1899 and the winter of 1899-1900, but the grasshoppers 

 appeared again in great numbers in the spring of 1900. During the 

 winter the Entomologist applied to the Government authorities of 

 Niital for culture tubes of a fungus disease which had proved 

 destructive to the grasshoppers in that colony. Through the kind- 

 ness of the Natal Government, Dr. Alexander Edington, director of 

 the Bacteriological Institute, Grahams Town, Natal, sent certain 

 tubes, which were distributed in the early summer of 1900. It resulted 

 by the use of these cultures that in one locality in Colorado and in 

 the Mississippi territory the disease took hold and spread with excel- 

 lent effec*^ and in both localities the swarms were greatl}^ reduced, 

 ahnost to the i>oint of non-danger. 



WORK ON GARDEN AND GREENHOUSE INSECTS. 



Investigations begun in previous years on insects injurious to truck 

 crops have been conducted along the same line, certain species affect- 

 ing the strawberry, raspberry, and blackberry, and others injurious 

 to cabbage and other crucifers having been given special study. 

 Several greenhouse insect jjests were injurious during the year and 

 have been the subject of investigation. A bulletin embodying the 

 results of some of the work on insects injurious to garden crops was 

 completed in February, 1900, and published soon afterwards. 



{b) EXPERIMENTAL WORK WITH REMEDIES. 



A series of experiments have been conducted to determine the rela- 

 tive insecticidal value of various kerosene mixtures, viz, an emulsion 

 made by combining Bordeaux mixture with kerosene, an emulsion 

 made with kerosene and a thin lime whitewash, and the use of kero- 

 sene and of crude petroleum undiluted; also a series of experiments 

 with lime applications. The effect of a thick lime whitewash on dor- 

 mant trees and scale insects was determined. The lime, sulphur, and 

 salt wash, so successfully employed in California against scale insects 

 on deciduous trees, was again tested. It was shown that when the 

 climatic conditions of the Pacific coast are duplicated in the East for 

 a sufficient length of time to allow the insecticide to operate, the appli- 

 cation is notably successful. A study was also made of the reactions 

 undergone b}^ this substance from a physical standpoint, and also 

 chemically, in conjunction with the Department Chemist. In con- 

 nection with the above experimental work, tests were made of the 

 application of boiling water to dormant trees to determine the effect 

 of heat alone in sprays ai)plied at a high temperature. 



An examination has been made, also, from time to time, parth" in 

 conjunction with the Department Chemist, of new insecticide mix- 

 tures. The use of fumigants as insecticides has also been under test, 

 especially in the continuation of the work cj^uoted last year, and the 

 use of the same gas (hydrocyanic acid) for disinfecting houses and 

 office buildings of vermin. The studj^ from time to time of the com- 

 position of proprietary insecticides by this Division with the aid of 

 the Department Chemist led this year to a very extended investiga- 

 tion of this?' subject. A ver}^ large and complete collection of insecti- 

 cides from tlie jiublic markets throughout the country has been nnide 

 by this Division in connection with the various entomologists of the 



