LXXXVITT TtEPORT OF THE SECRETARY OF AGRIOTTLTURE. 



1901, and has since been reprinted in more popular form. During 

 the past summer many inquiries have been received requesting infor- 

 mation and advice on the subject of mosquito and fly control, and these 

 have been answered by the publication in question and b}^ specific 

 advice. This investigation is being actively prosecuted; the field is 

 a very large one and of the greatest importance. While perhaps the 

 principal insects responsible for the transmission of disease have 

 received study, there remains very much yet to be learned of them, 

 and, furthermore, the Entomologist is in frequent receipt of new 

 material from this and other countries, and is constantly discovering 

 new facts bearing on this general problem. 



Unclassified Work on Injurious Insects. 



During the fiscal year investigations were taken up on supposed 

 insect damage to cocoanut and other palms in Cuba, Florida, and in 

 British Honduras. An article on the principal insects which act as 

 disseminators of the trouble locally termed "fever," and due to a 

 fungous disease, includes suggestions for methods of prevention of the 

 dissemination of the disease. 



Insect Determinations. 



An important line of work is the identification and maintenance of 

 records of the habits of injurious insects received from correspondents, 

 field agents, and others to serve as a basis for determining the best 

 means of controlling them. During the fiscal year 226 species not 

 hitherto studied at this Department received more or less attention, 

 and the catalogue number of biological series thus studied now reaches 

 9,667. 



The time of two expert assistant entomologists and several minor 

 assistants and aids is devoted to the preparation of material for per- 

 manent storage in the United States National Museum, for exchange 

 with other institutions, and for illustration and description. 



Experimental Work with Insecticides. 



During the year a considerable number of experiments with insecti- 

 cides and other methods of controlling insect depredations have been 

 conducted. A great many insecticide substances are constantly being 

 advertised, and many of them are sent to^tho Entomologist for experi- 

 mental examination and test either from purchasers or the manufac- 

 turers. Most of these are of very little value, or are combinations of 

 old and well-known insecticide substances, sold, however, as a rule, 

 under their new form at many times their real cost. The assistance- 

 of the Chemist has been invoked to determine the composition of these 

 substances, and he has recent)}" established a special section for insec- 



