1919.1 25 



ease had tlie i^onads been destroyed by Aimnteles or 3Iicroqasf^\'^mhj^ ^ . y^ 

 any Taehinid parasites examined by me. This is true even when all the "" j 



■fat-bodv has been removed from the immediate environ^ of th,e sfonads. "\'t 



The Cocoon or the Apakteles Larva. 

 After the parasites have passed out of the body of the victimized 

 T^ierine caterpillar, they adhere to the latter by the last abdominal 

 segment, which does not appear to be completely withdrawn at once 

 from the hole in the bod3'-w\all. Immediately the parasites Jiave com- 

 ))letely escaped, they begin to spin their cocoons. Those of Mi croc/aster 

 onnnexus, a parasite especially of Porthesin similis, are a beautiful 

 white, while those of Apanffles f/lomeratus are of an equally 

 beautiful golden yellow colour. 



The larva of Apanteles bends over as shown in text-figs. 3 and A; 

 and spins first of all a loose outer web around its body. In the majority 

 of eases it carries out this process as illustrated in text-fig. 4, beginning 

 at the bottom and gradually working upwards. In rarer cases it builds 

 the net from one side as shown in text-fig. 3. In the .legion where all 

 the larvae are crowded together, one larva attaches some of its threads 

 to those of its neighbours. The larva loops its first threads on to 

 the hairs of the caterpillar's body, but the attachment is never very close, 

 and the host is easilj' separated from its parasite cocoons. The times 

 taken for tlie preliminary steps of the formation of the cocoon have been 

 given, but after the latter is so thick that the occupant can no longer bp 

 seen through, it ma}^ work several hours longer before the silken casket 

 is finished. As is well known, the cocoon is extraordinarily tough and 

 strong. In my previous paper notes were given on the method of 

 exit of the imago from its cocoon, as well as of the hyperparasite 

 3re>;ocliorus. 



The Fate of the Pakasitized Larva op Pjeeis. 



The parasitized larvae of Pierines appear to be able to grow just as 

 lai-ge as the non-parasitized individuals. After the exit of the larvae, 

 the host caterpillar is left overpowered by the dreadful experience it has 

 undergone. If it is touched it moves feeblj'^, but for several days its 

 power of movement is curtailed ; in about a Aveek's time after the exit of 

 the parasites from its body, the holes probably become repaired and 

 filled up by the activity of the blood or body-wall cells. It is true that 

 after the exit of the larvae the body-fluid of the host can be expressed 

 by gentle squeezing, though if the caterpillar is not touched the exit of 



s 



