ii 



studied by Chittenden the chitinoiis process figured difters 

 considerably. It has pecnUarly sharp teeth in B. pisorum 

 in which the larva has got three ''apparent joints" in each 

 leg. In B. ohtectus which is said to deposit eggs on the 

 outside of the pods as well as inside, the teeth of the chiti- 

 nous process are blunter, but the legs are better developed. 

 The plate and legs in P. chinensis have already been described. 

 In B. quadrimaculatus, Chittenden says " the teeth are shar- 

 per and the thorax is armed on the lower portion of the plate 

 with three acutely pointed teeth on each side\" If by this is 

 imphed the lower teeth are absent in P. chinensis, Chitten- 

 den has failed to observe them in the latter species. In any 

 case there can be no doubt that there is a remarkable variety 

 in strength and form of the structure so peculiar to Bruchid 

 larvae which may help in explaining such apparently small 

 differences in the habit of egg-laying as oviposition on green 

 pods, dry pods, inside the pods, etc. It is proposed to dis- 

 cuss these in greater detail in the bulletin on free-living 

 forms. 



The Subsequent Hi.story of the Laeva. 



Soon after effecting entry into the seed, the larva 

 casts its skin. Before it does so it swells considerably, nearly 

 twice its size when hatched. The thoracic region is con- 

 siderably arched at the time and there is a kind of jerking 

 movement affecting the whole body, probably in order to 

 split the skin. The skin ruptures usually along the thorax, 

 but extends to the head as far as the triangular piece above 

 the labrum. The larva emerging from the skin is no longer 

 provided with the chitinous process. The legs are still 

 further reduced and appear only as conical prominences. 

 The mouth parts do not alter appreciably. The shape 

 assumed by the larva in the second instar, it continues to 

 have until pupation. The larva usually lies in a doubled up 

 condition. This enables it to move about in the chamber 

 with greater ease than if it lay along its full length. The 

 pupating chamber has as its boundary on one side, the seed 

 coat in which the larva cuts a ring. The chamber is 

 smoothened with a secretion from the larva, apparently 

 similar to that out of which a cocoon is formed in Cary-borus 

 gonagra. The period of pupation varies from seven to twelve 

 days. The adult after emergence remains in the chamber for 

 about two days until the integument hardens. Afterwards it 



\ Ohitteaden, loc. cit. footnote page 247. 



