238 ANNUAL EEPORTS OF DEPAETMENT OP AGEICULTUEE. 



wheat crop of 1918. At this writing steps are being taken to induce 

 the wheat growers to plow clown their 1917 stubble immediately after 

 harvest, to destroy all volunteer grain, and to plant their wheat this 

 fall at the fly-free date, as indicated by the entomological staff. 



In southeastern Nebraska,, southern Illinois and Indiana, and parts 

 of Missouri the fly is present, but not in alarming abundance. 



Some injurj^ to wheat in central California occurred during the 

 spring of 1917. Sj^ecial intensive investigations of the Hessian fly 

 are in progress in Illinois, Kansas, Nebraska, and Missouri. Prob- 

 ably it will be necessary to carry on these investigations for several 

 years before full results can be expected from them. 



Chinch bug. — Owing to favorable hiberating conditions during 

 the past fall and winter in Texas, Kansas, and Illinois, a chinch-bug 

 outbreak of considerable extent and severity seemed inevitable dur- 

 ing the early spring of 1917, but owing to extraordinarily heavy pre- 

 cipitation that occurred during the critical period of the egg-hatch- 

 ing season the situation has improved very materially throughout 

 the infested region. An illustrated poster giving advice for the 

 destruction of the bugs has been issued and distributed throughout 

 the infested area. 



White grubs. — A large flight of May beetles, well known as the 

 parents of the white grubs, occurred throughout Illinois, Wisconsin, 

 Michigan, Ohio, Pennsylvania, New York, New Jersey, and parts of 

 other Northern States during the month of June, 1917. The flight 

 consisted of two sections, designated as " Brood A" and " Brood C." 

 The occurrence of this flight means that throughout the area affected 

 the white grubs will be destructively abundant in 1918, which will 

 be the second year in the life of the resulting progeny. An illus- 

 trated poster giving methods of control has been distributed through- 

 out the region most badly infested b}^ the white grubs. 



-Alfalfa weevil. — The alfalfa weevil has invaded the Pacific slope. 

 The spread of the weevil has been slow and uniform, regardless of 

 the character of the country, whether cultivated or wild, and all 

 evidences indicate that it may continue to spread in the same manner. 

 One of the most common means of distribution is through the move- 

 ment of infested alfalfa hay, but the insects have been found also in 

 clothing worn on trains or carried in trunks. 



Several more or less satisfactory means of controlling the weevil 

 have been discovered and are being used extensively. These consist 

 of flooding the fields so as to cover them with sediment; spraying 

 with arsenicals in the spring and between cuttings ; progressive pas- 

 turing; and harrowing the fields when they are in a dry condition, 

 in order to produce something resembling a dust mulch, which kills 

 the insects. 



The European parasites of the weevil have continued to increase; 

 as high as 30 per cent of the weevil larvie present in midsummer 

 were found to be parasitized. These parasites now have spread 

 throughout the Webber Valley from 10 to 30 miles from the original 

 point of introduction. 



Corn earworm. — A rather severe outbreak of the corn earworm 

 occurred during the latter part of May and the early part of June, 



