532 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



years ago by Prof. Herbert Osborn, of the Oliio State University, 

 that the productiveness of pastures is very greatly reduced by these 

 insects, and it is hoped by this investigation to ascertain facts which 

 will bring about amelioration. 



"WORK ON INSECTS AFFECTING VEGETABLE CROPS. 



Work against insects affecting vegetable crops has been carried on, 

 as during the last two years, in different parts of the country. The 

 work has been both demonstrational and investigational. As pointed 

 out in the report for 1908, although the insects occurring in these 

 different regions are frequently identical, their habits and life his- 

 tories differ on account of the difference in climate, and require 

 either different remedies or modifications of the same remedy. The 

 work has been carried on as heretofore under the direction of Dr. 

 F. H. Chittenden. It is estimated that the annual loss in a number 

 of the most important truck-growing regions of the country from 

 insect damage is 20 per cent of the crop, and that the preventable in- 

 jury is about 15 per cent, thus indicating the value of the most up-to- 

 date knowledge in this direction. 



INVESTIGATIONS IN TIDEWATER VIRGINIA. 



Investigations reported upon in the last annual report, in cooper- 

 ation with the Virginia truck experiment station, the Virginia de- 

 partment of agriculture and immigration, and with associations of 

 truck growers of Norfolk, Va., and vicinity, have been continued. 

 Much demonstration work was found necessary, but some important 

 investigations have been carried on. It has been found that the pea 

 aphis may be successfully controlled by spraying early in the season 

 with whale-oil soap at the rate of G pounds to 50 gallons of water, 

 three or four sprayings being necessary for the best results. Tests 

 were made with different nicotine preparations against this same 

 species. Experiments with a lime-sulphur-arsenate-of-lead mixture 

 for the Colorado potato beetle were found quite effective, destroying 

 fully 95 per cent of the insects by a single application. Experi- 

 ments have been continued against the striped cucumber beetle, the 

 best results being obtained with a combination of arsenate of lead, 

 3 pounds, in Bordeaux mixture, 2-5-50, as a spray. The strawberry 

 leaf-roller has also been studied in this locality as well as certain 

 other insects. 



STRAVV^BERRY INSECT INVESTIGATIONS IN NORTH CAROLINA. 



Beginning with March, 1910, an agent was stationed at Chadboum, 

 N. C, to study strawberry insects. In 1908 the strawberry weevil 

 caused the destruction of 50 per cent of the strawberry crop in one 

 locality in North Carolina, the cash loss being $700,000. In 1909 the 

 loss in the immediate vicinity of Chadbourn was estimated at $150,000. 

 Especial attention was given to the life history of the species in the 

 locality mentioned. As a result of the preliminary study which has 

 been given to this species and the tests of remedies thus far, it is the 

 belief that the following four items of farm management will work 

 well in keeping strawberry fields free from weevil attack : 



1. Cultivation of a large acreage. 



