320 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



There has been an uuprecedeiited outbreak of the green clo\ er wonn 

 over the eastern United States, j^articuhirly along the Athmtic sea- 

 board, many fields of all varieties of beans being practically de- 

 foliated. Tliis pest was found to be controlled readily on truck 

 plantings by the application of suitable arsenicals. Studies of the 

 pea aphis on the Pacific coast are being continued. The pea moth, 

 recently introduced into the Northern States from Canada, has been 

 studied, and it has been determined that it is not of European origin^ 

 as formerly believed, but ncAv to science. 



CucuRRiT INSECTS. — Although a practical treatise on the striped 

 cucumber beetle and its control is available in the shape of a Farmers^ 

 Bulletin (Xo. 1038) recently issued, the insect is a difficult one to con- 

 trol and constant work is being done on it, especially in its role as a 

 carrier of a cucurbit disease, in an endeavor to discover more effective 

 methods for holding it in check. Certain repellents and poisons were 

 tested during the vear but found to be Avithout value. The Bordeaux 

 arsenate of lead mixture combined with other measures has proved 

 the best means for its control. Work on such important pests as the 

 melon aphis, the squash bug, and the squash vine-borer has been con- 

 tinued and results of an investigation of the squash bug are available 

 for publication. 



Insects injurious to cabbage and allied plants. — Extensive ex- 

 periments have been under way on the Pacific coast against aphids 

 affecting cabbage and other crops with the newly devised nicotine 

 dust spray as a contact insecticide. A monographic account of the 

 western cabbage flea-beetle, a pest of great importance w^est of the 

 Mississippi River, has been completed and is available for distribu- 

 tion. Much attention has also been given to the study of the life 

 history and habits of the other injurious flea-beetles which affect 

 cabbage, turnip, and related crops. The false cabbage aphis was the 

 cause of a severe outbreak on turnip, kale, and seedling cabbage in 

 early spring in Maryland and Virginia. The attack was of such 

 suddenness and severity that it coiJd not be checked, and it ceased 

 before control experiments could be completed. Preliminary work 

 on the European horseradish webworm, which has been a pest 

 for a number of years in Canada, has been carried on, especially in 

 reference to its recent occurrence in Virginia, and similar preliminary 

 work is being done on some other insect enemies of horseradish. 



Sugar-beet insects. — Work on the sugar-beet leafhopper, which 

 causes the costly condition known as " curly top," has been con- 

 tinued. The nature of the disease and the importance of tem- 

 perature, number of insects, length of feeding time, and other factors 

 in its production are being iuA-estigated. It has been found that 

 an interesting alternation of food plants, involving at least two 

 wild species^ occurs between the production of disease on sugar beets 

 and reinoculation. Three hundred and fifty types of resistant beets 

 selected from various California fields are being studied. The work 

 at Greeley, Colo., involving the control of the webworms injurious 

 to the sugar beet and investigations of the beet root-aphis, has been 

 temporarily abandoned, owing to a reduction of appropriations. It 

 is reported that serious injury to beet fields in eastern Colorado has 

 resulted from lack of instruction as to control measures for the sugar- 



