REPORT OF THE SECRETARY. 113 



rather well demonstrated that spraying will, under Florida condi- 

 tions, be more generally adopted in the future than control by fumi- 

 gation. The expert who was sent abroad in a search for the original 

 home of the white fly, and with the idea of importing from this 

 locality, when found, parasites or natural enemies which could be 

 established in the Florida orange groves, has been successful in at 

 least a part of his mission. In November, 1910, he found the white 

 fly at Seharunpur, India, under conditions that appear to indicate 

 that the white fly is indigenous to that part of the world. He has 

 found that it is attacked by two species of ladybird beetles, and he 

 has also found an internal parasite. A large part of the present 

 year has been devoted to the effort to secure the parasites in suffi- 

 cient numbers and in proper condition to permit sending them suc- 

 cessfully to this country. He has established the white fly on small 

 growing trees, and has secured living specimens of the parasite breed- 

 ing in these white flies, and the trees themselves will be brought to 

 the United States in Wardian cases. 



The investigation of the orange thrips, begun at Lindsay, Cal., 

 has been extended to southern California, especially in the Riverside 

 district, where it seems to be causing considerable damage. Appli- 

 cation of a spray consisting of a lime-sulphur solution with a to- 

 bacco extract added is the best remedy so far found. 



WORK AGAINST FOREST INSECTS. 



It is significant of the practical nature of the methods of bark- 

 beetle control recommended by the Bureau of Entomology and of the 

 practical demonstrations that have been carried on that no com- 

 plaints of depredations have come to the bureau during the year 

 from the areas in Colorado and Montana where control work was 

 carried on in previous years according to the instructions of the 

 bureau. During the past year the work has been principally in the 

 way of practical demonstrations, as the result of the investigations 

 of previous years. As an example, in cooperation with private 

 cwners in the vicinity of Columbia Falls, Mont., over 10,000 trees 

 were treated. Formerly 10,000 trees died each year, but as the result 

 of last year's work only 2,000 required treatment this year within 

 an area of more than 100 square miles. This is undoubtedly the 

 direct result of the control work of last year, which cost nothing, 

 since the treated trees when utilized for fuel and lumber are worth 

 far more than the cost of treatment. Work done in cooperation with 

 the Interior Department on the Glacier National Park resulted in 

 the treatment of 1,295 trees in the vicinity of McDonald Lake, and 

 the present conditions indicate that the work has been successful in 

 arresting the spread of the damage. 



231G5°— AGE 1911 8 



