BUEEAU OF ENTOMOLOGY. 249 



ndvantageoiisly that the ii'.ctliod 'will undoubtetlly be j:^onerally 

 adopted. The alfalfa vreevil is at present causing' niiich concern in 

 Colorado, and spraying work has been nndertaken in cooperation 

 with the officials of that State. 



(TKASSiiorPERS. — Much valuable assistance in the form of personal 

 advice has been given to State and county officials in the successful 

 conduct of grasshopper extermination work througliout the States 

 of Xorth Dakota, South Dakota, INIinnesota, Iowa. ]Montana, Cali- 

 fornia, Kansas, Nebraska, Missouii. Oi'egon. and Washington during 

 the bummer of 1918 and spring of 1919. The loss of many hundred 

 lliousand dollars' worth of crops has been prevented as the result 

 of these activities. 



Other insects affectiisg cereal and forage crops. — Studies of the 

 jointworms have been continued with excellent results. Control ex- 

 periments with the alfalfa-seed Chalcis have been carried on in coop- 

 eration with the Arizona Commission of Agriculture and Horticul- 

 ture in the Buckeye Valley of Arizona, resulting in an apparent 

 decrease of 15 per cent in th.e infestation and a net profit of more 

 than $43 per acre in the experimental plot. 



Experimental control Avork on the coulee cricket conducted during 

 the spring of 1918 was apparentlj'' successful, and the insect has made 

 no destructive appearance during 1919. 



Studies of the alfalfa caterpillar, the harvester ant. white grubs, 

 billbugs, wireworms, and the European sawfly in wheat have been 

 continued Avith favorable results. The last-named insect has been 

 watched with especial care, because it seems capable of doing con- 

 siderable damage to the winter wheat crop under conditions favor- 

 alle to its multiplication. 



STORED-PRODUCT INSECT INVESTIGATIONS. 



Dr. E. A. Back has continued in immediate charge of this branch 

 of thi bureau's work. 



Corn weevils. — During the past year a laboratory has been estab- 

 lished at Orlando, Fla., for the ])urpose of studying the biology and 

 methods of control of corn Aveevils. Enough has already !)een learned 

 of the biology of these insects to form the basis for control work. 

 At Athens, Ga., an office has been established in cooperation with 

 the Georgia Agricultural Experiment Station, from which expert 

 information regarding preserving corn from weevils has been dis- 

 seminated among southern farmers. 



Bean and pea weevils. — The great increase in weevil losses to Cali- 

 fornia-grown beans and peas during the past few years has led to 

 the establishment of a laboratory at Alhambra. Calif., at which the 

 causes for weevil increase and the methods of control are Ijeing inves- 

 tigated. The work has received the hearty cooperation of the bean 

 growers and warehousemen of the Pacific coast. 



Flour beetles. — The biology of various species of flour beetles of 

 the genus Tribolium that attack flour in all warehouses throughout 

 the United States is being made the object of an especial investiga- 

 tion with headquarters at Dallas, Tex. 



151352°— 19 17 



