108 Weevils of the Genus Sitona 



In relation to the vestigial character of the wings of S. sulcifrons, it 

 is interesting to note that this species is often more abundant throughout 

 the clover in first and second year "seeds" than any winged Sitona of 

 the same habits, showing that impossibihty of flight is no check to the 

 local dispersal of the species. More information is required as to how 

 much such winged species as S. flavescens, puncticoUis and hispidula fly, 

 and any observations on this point would be gratefully received. These 

 species are very active upon their legs, but up to the present I have 

 rarely observed any of them on the wing, and it seems probable that 

 in many cases they may migrate to new crops in the same manner as 

 S. sulcifrons. 



The Egg. 



The egg is similar to that of S. lineata. It varies shghtly in size and 

 shape from 0-37 mm. by 0-27 mm. to 041 mm. by 0-31 mm. 



The Larva. 



The larva is very like that of S. lineata and measures when full grown 

 about 4-9 mm. 



The Pupa. 



The pupa measures from 3-2 mm. to 4-9 mm. 



Life-History. 



Sitona sulcifrons is a smaller species than S. hispidula and the egg, 

 larval and pupal stages are all a httle shorter. The reproductive organs 

 of the adult also mature more quickly. Otherwise the hfe-history of this 

 species much resembles that of S. hispidula and has been determined 

 by similar breeding experiments and field observations which will be 

 summarised as briefly as possible. 



I. The Imagines. 



Length of life and period of Oviposition. Newly emerged specimens, 

 sexually immature, were taken in Suffolk in the end of July, and in 

 Ross-shire on August 10th. Sleeved upon clover, oviposition commenced 

 on September 12th and 25th respectively, and this was corroborated by 

 field observations. Placed in pots of clover covered with muslin out of 

 doors in Ross-shire, the majority survived the winter, and some Uved 

 until the following August. In the field, the beetles continue to feed 

 during the winter, and even lay a few eggs. In April and May oviposition 

 recommences vigorously, but few eggs are laid in June and still fewer in 



