288 Bionomics of Weevils 



forwarded me a large number, all newly emerged, collected from beans 

 on July 30th, but observed that earlier in the month no specimens of 

 lineatus were obtainable. In captivity larvae collected from pea-roots in 

 Kent on June 5th did not mature to weevils till the end of July and the 

 beginning of August, but I have always found that collected larvae 

 take longer to mature than those left undisturbed. In Ross-shire eggs 

 laid from 25th to 28th May produced weevils towards the end of August. 

 On emergence none of these weevils paired or laid eggs, and in order to 

 see when they would do so under the most natural conditions possible 

 I placed them in sleeves of muslin fastened tightly on to plants of peas 

 or clover growing in pots (Plate XVIII, fig. A). These sleeves have proved 

 very satisfactory, as the black eggs can be clearly seen upon them while 

 they would be difficult to find if laid directly on the earth. The weevils 

 also have plenty of fresh food and air. No eggs were laid by these speci- 

 mens until the following spring, when on May 23rd the first female 

 commenced oviposition. In the field I collected numbers of newly 

 emerged weevils in Ross-shire in August and September, but none of 

 these laid eggs until May 17th next year. In Kent, in October, I collected 

 hundreds of weevils of S. lineatus and kept them under close observation, 

 but not a single egg was laid by them that year. I placed a large number 

 of these specimens on the sleeves described above and left them in Kent 

 under the charge of Mr P. F. Kendall, who forwarded a sleeve to me 

 each month, but none of these English weevils, even when kept in their 

 own climate, laid any eggs until next spring when oviposition com- 

 menced on May 6th. 



Conclusive proof that the weevils do not lay eggs the same year as 

 they emerge will be shown in dealing with the reproductive organs. 



On emergence the weevils commence to feed upon the peas and 

 beans hut do little harm as the plants by this time are full grown. When 

 the crop is harvested the weevils mostly disperse and some are carted 

 away with the crops, but a few are to be found in mid-winter on the old 

 fields. I have taken these weevils abundantly on lucerne in Kent in 

 October, also on clover and medick, and a few were present on bean 

 plants that had grown up from fallen seed. In that month I also found 

 numbers sheltering in a stack of pea straw and I took a few specimens 

 again in this stack in the beginning of April. During the winter I have 

 found the weevils sheltering amongst long grass beside which there was 

 no clover. In captivity they thrive well with very little food during the 

 winter. Thus in August I placed 15 specimens upon a pot of peas. The 

 peas died during the winter and the weevils had no subsequent food, 



