300 



eggs upon tlie stored and damaged beans, and another generation will 

 soon develop. This may go on indefinitely, or until the food sui)ply is 

 exhausted, although in closed receptacles the beetles always appear 

 anxious to escape. 



The first published record of this continuous breeding in stored beans 

 was probably our note in 1882, above alluded to, where, in reply to a 

 question from a correspondent in Bremen, Ohio, we wrote: ''Unlike 

 the Pea Weevil, the Bean Weevil continues to multiply in the stored 

 beans. These, when infested, are usually reduced at last to nothing 

 but powder, and have no value as seed." 



In 1878-'79 we made a number of observations upon this species, from 

 which some interesting points have been determined. On December 

 31, 1878, we received from Indian Territory a lot of badly infested 

 beans, from which many beetles had already issued. Close examination 

 showed that larvae in all stages of growth and pupie were still contained 

 in the beans. January 21, 1879, a dozen beetles, just issued, were placed 

 in a vessel with sound black beans for observation. Two days later 

 quite a number of eggs had been deposited. They were simply glued 

 to the outside of the beans, no cavity having been provided for them 

 by the beetles. A few were found loose in the jar. These eggs were 

 0.7 mm. long and 0.3 mm. in diameter at the stoutest part. They were 

 white, and closely granulated. February 8, or sixteen days after ovipo- 

 sition, two of the eggs hatched. The young larvae moved about quite 

 briskly, and when in motion curved the body at each step. This it is 

 enabled to do by the possession of temporary legs, while its other char- 

 acters, as compared with those it assumes within the bean, fit it for 

 moving over and penetrating the smooth but rather thin skin of our 

 ordinary beans. , 



Bruchus fabje — First larva. — The larva at this stage presents a very curious 

 appearance and differs widely in important characters from the second stage. The 

 body is hardly so stout in proportion to its length; the prothoracic plate bears two 

 pairs of projecting spurs, the hinder pair having each a serrate edge of four teeth, 

 and the anal plate also bears four horny, pointed tubercles. On the head there are 

 two very evident eye spots ; the anteunje are four-jointed, and bear side jjieces arising 

 from the basal joint. The mandibles have two blunt teeth and the labium is large 

 and fleshy, and is diflerentiated into two viscid, papillose paraglossae and a central 

 ligular prominence with two papilltB. The insect at this stage differs, however, 

 most notably from the more mature larvse in possessing six postembryonic legs, as 

 shown at Fig. 43. Each of these legs is composed of three apparent sclerites, the 

 basal one stout, coxa-like, and scarcely differentiated from the body. The second is 

 long and slender and may correspond to the fused femur and tibia. This joint bears 

 several hairs at its tip and gives rise to the third joint, which we may call the tarsvis, 

 and which is much more slender than the second joint and is broadened at its tip 

 into a flat pulvillus, bearing at the heel a single delicate spur, as shown at Fig. i3g. 

 Nine spiracles are plainly seen, eight being abdominal and one mesothoracic. There 

 is a row of very long, subdorsal hairs, a shorter row between this and the median 

 line, and another lateral row intermediate in length between the two just mentioned. 



We are not aware that similar structural peculiarities in the first 

 larval stages of Bruchus have been pointed out before. They seem to 



