IMPERIAL BUREAU OF ENTOMOLOGY. 



REVIEW PVeB211917'^- 



OF \ 4^y.. 



APPLIED E X T M L OtTTr 



Series A. 

 Vol. v.] [1917. 



Reeves (G. T.), Miles (P. B.), Chamberlix (T. R.), Snow (J. S.) & 

 Bower (L. J.). The Alfalfa Weevil and Methods of Controlling it. 

 — U.S. Dept. Agric, Washington, D.C., Farmers' Bull. no. 741, 

 17th July 1916, IG pp., 7 figs. [Received 19th October 191G.] 



This bulletin deals with the manner in which Hypera variabilis, Hbst. 

 {Phytononius posticus, Gyll.) (alfalfa weevil) is spreading and with 

 methods of controlling it. This insect does an enormous amount of 

 damage to the lucerne crop, and in Utah the annual loss is estimated 

 at £600,000. No definite channels of distribution have been 

 discovered, but recent observations point to the weevils being carried 

 in green lucerne hay or new hay of the second crop, or on the 

 clothing of persons who have been in infested fields. The spread of 

 this pest appears to occur along high roads, rather than along railway 

 lines, which tends to confirm the theory that they are carried by 

 persons travelling along country roads. It is slowly spreading in all 

 directions and may in time infest most of the United States. No 

 isolated colonies distant from the main area now infested have been 

 reported, though the weevils have been found in railway trucks, 

 especially refrigerator cars. 



A full account is given of the life-history of this weevil and 

 the relation between its habits and the methods that must be 

 employed for its destruction. Spring cultivation is expensive 

 and does not have any appreciable effect on the weevils, but hastens 

 the growth of the crop, so that, in spite of the pest, a large yield is 

 obtained when an early cutting is necessary. Spring spraying with a 

 mixture of four pounds of zinc arsenite in 100 U.S. gallons of water, 

 using 50 to 100 gallons to the acre, is often effective. Arsenate of lead 

 can be used in place of this, but is usually less satisfactory. It is often 

 desirable to employ both these methods. If spraying cannot be carried 

 out, pasturing the crop of lucerne before the eggs have hatched is often 

 beneficial. The amount to be grazed must be limited to the head of 

 stock, so that it may be cropped effectively and the herd moved to fresh 

 ground as soon as each area has been cropped ; this should be in about 



fC330) P.l/106 1,500. 1.17. B.&F.Ltd. Gp. 11/3. a 



