96 Weevils of the Genus Sitona 



by breeding experiments. Eggs were introduced into pots of clover 

 covered with muslin (10, p. 283, Plate XVIII, fig. B). In uninfected pots 

 the clover remained strong and healthy, but in pots infected with eggs 

 of S. hispidula much of the clover died before the larvae had ceased 

 feeding owing to the damage they had inflicted upon the roots and the 

 plants that survived were thin and weak. The larvae bored deep holes 

 all over the main root and when half grown they were sometimes found 

 entirely buried in the root. The portion of the root just below the crown 

 of the plant was frequently chosen for attack with the result that the 

 shoot immediately above the damaged area died. In all the larger plants 

 so affected the outer shoots were dead from this reason whilst in small 

 plants the whole root was sometimes bitten through at this point. The 

 surface of the main roots were also gnawed in patches, the side rootlets 

 were bitten off and the nodules destroyed. The gnawed portions of the 

 root decayed and turned brown. 



Field observations indicate that the greater part of the injury is done 

 in June and July when the larvae are most abundant and plants of clover 

 with the roots injured as described above have been dug up from the 

 fields in these months and from the larvae that were found beside them 

 adults of S. hispidula were duly reared. 



Description of Adult. 



Black, clothed on the dorsal surface with scales of various shades of 

 brown and ochreous and with long erect setae on the elytra. Length 

 3-3-4-7 mm. 



Head. Eyes flat, scarcely projecting from the sides of the head. 

 Forehead between the eyes completely flat but with a narrow central 

 furrow which is continued upon the rostrum. 



Pronotum. Broader than long, sides strongly rounded. Covered with 

 large diffuse punctures between which are smaller punctured dots, and 

 bearing numerous short raised setae pointing forwards. Scales rather 

 broad and closely placed, of uniform colour, but varying in different 

 specimens; purphsh brown or greyish brown. Raised setae black or 

 white. Broad subdorsal bands and a narrow interrupted dorsal line com- 

 posed of bright ochreous or whitish scales are usually present. The 

 anterior coxal cavities separated from the presternal line by an area 

 equal to the breadth of the presternum^ (Eig. 5). 



^ Reitter (13) in his key to the genus Sitona makes use of the character afforded by the 

 position of the anterior coxal cavities in regard to the transverse furrow behind the anterior 

 edge of the prosternum. This furrow which he calls "die Abschniirungslinie hinter dem 

 Vorderrande der Vorderbrust," I here designate as the prestemal line and the area between 

 it and the anterior margin as the presternum. 



