518 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



Massachusetts and to the vicinity of New York City, has rendered it 

 desirable to attempt the importation of some of tlie known European 

 insect enemies of this species. This effort has been made during the 

 fiscal year, but it is too early as yet to observe any result. Further 

 attempts were made to introduce European enemies of the elm leaf- 

 beetle, but as yet without success. 



It has been ascertained that the ejrgs of the tobacco hornworm in 

 Porto Rico are destroyed by parasites, and in consequence, through 

 the courtesy of Prof. W. V. Tower, a large number of parasitized 

 eggs were sent to Clarksville, Tenn., the headquarters of the tobacco- 

 insect investigations of the Bureau. The parasites emerged in due 

 time, but through some defect in manipulation that may be remedied 

 as a result of future work none of them could be induced to attack 

 the native eggs. 



EXPORTATIONS OF USEFUL INSECTS. 



Prof, Antonio Berlese, of Florence, Italy, reports the continued 

 spread of the American parasite of the mulberry scale and anticipates 

 complete relief. 



Exportations of American coccinellids have been made to Prof. F. 

 Silvestri, of Portici, Italy, for the purpose of feeding upon this same 

 scale insect. These coccinellids have been reared at Portici and 

 have been liberated in mulberry groves at Acerra. The Chief of the 

 Bureau, visiting in Italy in May, 1910, took with him a large box of 

 these American coccinellids, which arrived at Portici in almost per- 

 fect condition, and from them Professor Silvestri expects excellent 

 work. 



Shipments of the parasite of the brown dog tick were made to 

 officials in South Africa and to Italy. 



AVORK ON INSECTS AFFECTING SOUTHERN FIELD CROPS. 



The work on insects affecting southern field crops deals with the 

 following problems, in accordance with the classification made a 

 year ago : 



1. The cotton-boll weevil and other species injurious to cotton. 



2. Insects injurious to tobacco. 



3. Insects injurious to sugar cane and rice. 



4. The Argentine ant. 



5. Insects injurious to cacti utilized for food. 



This work is conducted, under the direction of Mr. W. D. Hunter, 

 by four trained assistants, located, in so far as possible, in the regions 

 where the loss is greatest. 



COTTON-BOLL WEEVIL INVESTIGATIONS. 



The growing season of 1909 was very abnormal as regards damage 

 by the boll weevil. Although the infested area increased as usual 

 in the autumn, the damage in general was much less than is to be 

 expected in a normal year. An unusually small number of weevils 

 issued in the spring, owing to abnormal winter conditions. Un- 

 precedented dryness, which began early in the spring, was continued 

 throughout a large part of the growing season and checked rapidity 

 of multiplication. Considerable damage, however, was done in 



