232 



MR. A. M. ALTSON ON THE LIFE-HISTORY AND 



Braconid was found to be in the full-grown larval stage, and was 

 only partially dried up. In endeavouring to move the active larva, 

 the integument was punctured by the needle, and its unvoided 

 waste instantly exuded. This caused the writer to form the 

 opinion that the four dead larvae of the Chalcid might possibly 

 have met their death by a similar agency — the setre and sensory 

 hairs (text-fig. 5) on the integument of the full-grown Braconid 

 larva. 



Experiment No. 2.— Another examination into this point was 

 therefore carried out. On 30th December four normal-sized 

 puparia, which when fractured disclosed the Braconid lining, were 

 placed separately in glass tubes Nos. 1-4, and into each two 

 fertilized Nasonici females were admitted, and a smear of food 

 made on the inside of each tube. They were then corked. 

 On 31st Dec@ml)er — the next day — tube No. 3 was found to 

 contain an active xi, manducator male. The male was released 

 in the Braconid cage, the Nasonia females \^ ere replaced by new 

 ones, and another puparium — a small one — obtained and put into 

 tube 3. Occasional examination of the tubes was maintained, 

 and, when necessary, fresh smears of food made. On 9th January 

 both females in tube No. 2 were dead. On lOtli January, tube 

 No. 1 was found to contain an active A. manducator female ; the 

 Nasonia females were still active. A new puparium was put into 

 the tube, and that from which the Braconid female had emerged 

 w^as examined. Nothing bearing any resemblance to Chalcid larvae 

 or eggs was found ; the puparium contained the Braconid larval 

 exuvium, pupal exuvium, the meconium, and white cement-like 

 discharge. On 11th February tube No. 4 was found to contain 

 an active female Braconid ; both Nasonia females were dead. The 

 puparium was examined, and besides its normal contents, two 

 small masses were found adhering to the lining but which were 

 not distinguished. The Nasonia females in tubes Nos. 1 and 3 

 were observed to be dead. On 10th March the contents of tubes 

 1, 2, and 3 were examined. No. 1 puparium was opened, and 

 found to contain a dead and shrivelled larva of A. manducato7\ 

 and attached to it was a dead Chalcid larva, and loose in the 

 puparium two living Chalcid larvje. No. 2 puparium contained 

 a dead and shrivelled larva of A. manducator with four dried and 

 shrivelled Chalcid larv£e — very small ones — and all adhering to 

 their host. The puparium in No. 3 tube was examined, and 

 towards the cephalic ventral end of it a slit was observed, through 

 which part of the head of an adult Braconid could be seen, as 

 though it had tried to emerge. It was then observed whilst 

 opening the puparium that, at the point where the writer had 

 made a fracture mid-dorsally in the first place, this had either 

 been carelessly done, or the female — for such it was — had extended 

 it in her efforts to emerge when bringing the necessary pressure to 

 bear upon the cephalic end in order to get her mandibles into it, 

 as she would cause the anterior half to bend with her, so that it 

 acted as if hinged, and thus frustrating her efforts to emerge. 



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