Volume IX JUNE, 1922 No. 2 



BIONOMICS OF WEEVILS OF THE GENUS SITONA^ 

 INJURIOUS TO LEGUMINOUS CROPS IN BRITAIN 



By DOROTHY J. JACKSON, F.E.S. 



PART II. 



SITONA HISPIDULA F., S. SULCIFRONS THUN 

 AND S. CRINITA HERBST. 



(With 5 Text-figures and Plate III.) 



A. SITONA HISPIDULA F. 



SiTONA HISPIDULA F. is widely distributed throughout Europe and 

 America and is a recognised pest of leguminous crops in both continents. 

 It is also recorded by Allard(i) from Western Siberia. In America its 

 depredations appear to be only of recent date, as prior to 1876 this 

 species was not known to occur, but in that year it was observed in New 

 Jersey, and in 1889 its sudden spread in America was noted by Schwarz (15). 

 It has since extended westward, and its first appearance in California 

 was recorded by Van Dyke(20) in 1917. 



In the British Isles it is common and widely distributed, and wherever 

 present, is injurious to clover and lucerne, though the damage caused by 

 it in this country has hitherto escaped recognition. The Hfe-history of 

 this species has been investigated by Wildermuth(22) in America, but in 

 Europe only a few observations have been recorded by Brischke(4) in 

 Western Prussia. Hitherto no account of the life-history of this species 

 in Britain has been pubUshed. 



Food-plants. 



All species of clover {Trifoliiim), lucerne {Medicago saliva), medick 

 {Medicago lupulina); rarely upon peas. 



At Wye, Kent, this species was common upon lucerne in most months 

 of the year; it also occurred on temporary clover leys, in fields of perman- 



^ The name Sitona Germ, is here adopted in place of Silones Schoenh. on account of 

 priority, Germar (9) having named this genus Sitona in 1824. Schoenherr (16) in 1826 and 

 again in 1834 (17) also uses this name, but in 1840 (18) changed it to Sitones. 



Ann. Biol, ix 7 



