DIVISION OF ENTOMOLOGY. 145 



point to decide, if possible, the question of the original home of this 

 scale, since this original home once found, it is quite fair to suppose 

 that there also may be found efficient parasites. The' evidence accu- 

 mulating during the past two or three years has pointed quite strongly 

 toward Japan, and in the spring of 1901 a competent assistant, Mr. 

 C. L. Marlatt, was sent to Japan for the purpose of studying this 

 question upon the ground. Unexpectedly to most entomologists in 

 this country, although not to the writer and to the investigator, it has 

 been quite definitely ascertained that the San Jose scale is not indige- 

 nous to Japan, but that, quite to the contrary, it was introduced into 

 that country from the United States upon fruit stock. Nevertheless, 

 an allied scale, known in this country as the West Indian peach scale, 

 has been found to be indigenous in Japan, and to possess efficient 

 natural enemies which also prey upon the San Jose scale. An attempt 

 is being made to introduce these natural enemies into this country, 

 and further efforts will be made, by continuing the journey, to find 

 in oriental regions the true original home of the San Jose scale. 



INSECTS AS CARRIERS OF DISEASES OF HUMAN BEINGS. 



This subject of investigation, while, perhaps, it may be considered 

 only indirectly agricultural, comes distinctly within the province of 

 this Division, since it is the only governmental institution concerned 

 with work in economic entomology; and, also, anything which relates 

 to the health and well-being of agricultural classes is agricultural. 

 Aside from their disease-bearing relation, mosquitoes are in part- 

 responsible for the nonavailability of large tracts of land of great 

 agricultural possibilities. 



As a consequence, much attention has been paid to the general 

 subject of mosquitoes, especially in their relation to disease and in 

 the search for the most efficient remedial measures. 



In August, 1900, a comprehensive bulletin was published dealing 

 with North American mosquitoes, which has been used extensively 

 by physicians in different parts of the country as a guide in distin- 

 guishing all those which carry malaria, as well as those which have 

 probably no disease relation, and in learning about the breeding places 

 of the former. It also dealt largely with the subject of remedies. 

 Investigations of the office on the subject of mosquitoes were carried 

 on throughout the year. Advice was given by correspondence to 

 many communities and organizations of individuals engaged in anti- 

 mosquito work, and in cooperation with the Division of Soils some 

 work was done looking toward the reclamation of brackish marshes, 

 which are great breeding places of mosquitoes. 



There was completed during the year an investigation of the insects 

 breeding in or attracted to human excreta, for the purpose of deter- 

 mining what flies may be safely said to take part in the dissemination 

 of typhoid fever. These results have been published in full, and will 

 be summarized in Bulletin No. 30 (new series) of the Division of Ento- 

 mology, and a short article on the general subject of insects as car- 

 riers of disease will be published in the Yearbook for 1901. 



WORK UPON INSECTS DAMAGING FORESTS. 



The investigation undertaken for the Division by Dr. A. D. Hop- 

 kins in the spring of 1901 upon the insects injuring forests in northern 

 New England was completed, and a bulletin describing the results is 

 now in press, and will appear as Bulletin No. 28 (new series). 



AGR 1901 10 



