226 ANNUAL EEPOETS OF DEPARTMENT OF AGRICULTTJEE. 



amount of study, and the results of tlie applications of lead arsenate 

 and Paris green for the tomato fiiiitworm are available. 



Sugar-beet insects. — The false chinch bug has been studied for 

 two years and a report is forthcoming during the year. Blister 

 beetles, especially those which affect sugar beets as well as potatoes, 

 were investigated in Kansas. In Colorado the sugar-beet webworm 

 received continued study, and substantial progress was made. Large- 

 scale experiments have definitely proved that this, one of the most 

 important enemies of the sugar beet, can be easily controlled with 

 arsenicals. Grasshoppers in their relation to sugar beets w^ere studied 

 in Kansas and a report has been completed. In previous years the 

 beet leafhopper, which is the cause of the ''curly top" condition, was 

 locally extremely injurious and was investigated in the States of 

 Utah, Idaho, and California. The study of its hfe history in Idaho 

 has been completed and numerous experiments have been carried on 

 in which its injury has been compared with that inflicted by other 

 sugar-beet pests. Kerosene emulsion, nicotine sulphate, creosote 

 compounds, and fish-oil soap have given negative results as sprays. 

 Work is in progress in California and has been begun m Wisconsin. 

 Sugar-beet wireworms have been the subject of experiments addi- 

 tional to those published in Bulletin No. 123 of the Bureau of Ento- 

 mology, with the main idea of finding better and cheaper methods of 

 control, including the use of various attractive baits. 



Onion insects. — Work on the onion thrips was continued during 

 the year to make possible a report on its life history, especially in 

 Indiana and southern Texas, as well as in other localities. The onion 

 maggot, which feeds on the bulbs, was the subject of special investi- 

 gation in Wisconsin from the standpoint of control measures, these 

 being chiefly the use of repellents to prevent oviposition about the 

 onion plants. Incidentally other root-maggots, including the seed- 

 corn maggot and the barred-wing onion maggot, received attention. 



Pea aphis. — Investigations of the pea aphis were conducted in the 

 States of Vhgmia, Michigan, Wisconsin, and California, at stations 

 established there. New remedies were compared with old, and 

 additional life-history studies, according to locahty, were conducted. 

 In coimection with the pea aphis a comj)aratively unloiown species, 

 the pea mite, was studied in California. 



Insects affecting cruciferous crops. — The cabbage looper was 

 imder continuous observation as in previous years, and a full report 

 will soon be available. The cabbage mago;ot was the object of special 

 study in Wisconsin and Michigan. The horse-radish flea-beetle and 

 other flea-beetles received attention in different States, including 

 Wisconsin, Colorado, and Kansas. Progress was made in the study 

 of the western cabbage flea-beetle in Kansas, where this species is 

 very destructive. Experiments with nicotine sulphate, fish-oil soap, 

 and arsenicals, including arsenite of zinc, gave varying results m 

 control, but arsenate of lead proved the most effective of all, its action 

 being chiefly repellent. ExceUent progress was made in investiga- 

 tions of the diamond-back moth, but some points require verification 

 before a final report can be furnished. 



Insects injurious to cucurbits. — The melon aphis, the principal 

 enemy of cucurbits in many portions of the country, was the subject 



