LOUISIANA CIRCULAR No. 5. 15 



<>f solution but which, after careful study and investigation by 

 entomologists, have been solved satisfactorily and effective 

 means of control devised which have resulted in the saving of 

 hundreds of thousands of dollars to the farmers interested. 



Prolonged ^investigation of the cotton boll-worm (an insect 

 entirely distinct from the boll weevil) has given us a thorough 

 knowledge of its habits and development, and this knowledge has 

 indicated the proper cultural measures to be employed against it. 

 with the result that many progressive cotton planters now suffer 

 a loss of less than 5 per cent of their crop, whereas before the 

 adoption of these measures their loss was from 20 to 30 per cent, 

 and even as high as 40 per cent. This saving has been accom- 

 plished without any increase in the cost of making the crop. 



The Hessian-fly, which in former years destroyed from 20 

 to 90 per cent of the winter wheat crop in various parts of the 

 winter wheat belt, can now be controlled completely by cultural 

 measures which do not involve any extra expense in the produc* 

 tion of the crop. Prof. F. M. Webster, upon a careful study of 

 this insect, found that the adult fly emerged at almost the same 

 date each year to deposit eggs upon the young wheat plants, and 

 that the amount of rainfall for a few 7 weeks preceding, either re- 

 tarded or accelerated the development of the adult flies, so that, 

 the rainfall being known, the time of appearance of the flies 

 could be accurately forecasted. By delaying for a few days the 

 sowing of his wheat in the fall, the farmer can prevent entirely 

 the damage from this insect, for the females cannot deposit their 

 ^ggs upon wheat plants that do not come up until after the adult 

 flies have died of starvation. The farmers in the winter wheat 

 sections were quick to see the enormous benefits to be derived 

 from this simple measure, and at present the wheat-growers of 

 Ohio, Kentucky and adjacent States are no longer compelled to 

 pay heavy toll to this insect. 



The San Jose scale,* which for a few years threatened to 

 make the growing of peaches, plums and apples an impossibility 

 in the United States, was a far greater terror to the fruit grow- 

 ers than is the boll weevil to the Louisiana cotton planter at pres- 

 <nt, yet by the patient and careful investigations of various State 



*The San Jose scale is discussed, and remedies for it given, in Circular No. 

 4 of the Crop Pest Commission, which will be sent to any farmer upon request. 



