170 

 Bean Weevil {linichii.'i obtecliis. Sav.) 



(Fig. CO.) 

 Attach. — Small bpetles closely resemblin,!,' in .sliajie and movement tlir 

 pea weevil, but only half its size, namely, 1-10 of an inch long, oval iu form, 

 with the head bent down and more or less concealed as seen from above, and 

 prolonged into a short, squarely-cut snout. Antenme distinctly jointed, and 

 enlarging towards the tiii ; the first four and the last joints reddish. The 

 wing covers marked with ten impressed and dotted longitudinal lines. The 

 whole body covered with short, .silky hairs. The lines on the wing covers are 

 broken up into pale, yellowish dashes and dark-l)rown spots. The tip of the 

 abdomen extends beyond the wing covers and is of the same reddish tinge 

 as the tips of the antenna; and the legs, but is covered more or less with 

 short, silky hairs and bears a central white line, but there is no appearance 

 of the two black spots which are so conspicuous in the pea weevil. 



'Flu- life history of the bean weevil differs in some important points from 

 tliat of liie ]jea weevil. The eggs of both are laid upon the pods while these 

 are young and tender. On hatching, the young grub of the bean weevil eats 

 its way inside and penetrates one of the forming beans, several grubs entering 

 a single bean, each one forming for itself a distinct cell. They become full- 

 grown and change to pupa; in the autumn, and a little later to the perfect 

 beetles. The date of emergence from the seed depends very much, as in the 

 case of the pea^weevil, on the temperature in the autumn months: it may be 

 in the late autumn or not until the si)ring: when the seed beans are stored 

 in a warm building, the beetles may emerge at any time through the winter. 

 One of the important differences between the life histories of the pea and 

 bean weevils is that, whereas in the case of the former the young grubs can 

 only enter the soft, green seeds, those of tlie bean weevil can propagate for 

 three or four generations in the dry stored seeds. This fact renders the 

 well known domestic remedy for the pea weevil of holding over the seed for 

 two years (piite ineffective in the case of the bean weevil : that is. if a bag 

 of pease infected with pea weevil were put away for two years, the pea 

 weevils would emerge the first spring and die in the bag. But, iu the case 

 of a bag of beans infested by the beau weevil ke|it in the same way, the 

 beetles on emerging would at once set to work to lay eggs upon the beans. 

 The young grubs when hatched would penetrate the dry seeds and go through 

 all their stages, and this breeding might be repeated as Ions fts the supply of 

 beans lasted. Curiously enough, the pea weevil does ni)t bore holes through 

 the paiier or cotton bags in \\hich infested seed has been stored, but iu the 



