1915.] 41 



the good offices of Dr. B^vini;-, of the U.S. Bureau of Entomology, 

 have also been able to decipher Adlerz's main paper [loc. cit. Bd. 3, 

 No. 4, pp. 1-48, with interesting plate (1906)]. 



Bouwman was only able to observe two encounters and remarks 

 that " the first sting entered the thorax from below and paralysed the 

 dangerous mandibles," but he does not give precise details of this 

 part of the story. His paper contains a valuable series of photo- 

 graphs of the development of the Methoca larva on its host. 



Adlerz observed some ten acts of oviposition (at least in the 

 eai-lier stages) on the part of each of two $ ? , and I now find that 

 his results differ from ours in one important point concerning wliich 

 I give a translation from his resume :".... the Methoca begins to 

 manoeuvre round the snapping larva, till she gets an opportunity to 

 slip on to the lid (i.e., the cephalothoracic shield of the larva, at the 

 top of the burrow) from the dorsal side. Instantly her head or the 

 front part' of her thorax is grasjied by the sicMe-shaped tnandibles of 

 the larva, and as the latter raises its head in so doing the Methoca is 

 given the opportunity to sting the larva in the throat or hetweev the 

 front coxae. The larva is at once paralysed, and the Methoca rests at 

 the edge of the burrow till the poison works its full effect. After a 

 short time, the Methoca pushes past the head of the larva down into 

 the burrow. These operations were followed by the repeated stinging 

 of the ventral thoracic segments, as also seen by Bouwman and our- 

 selves ; but the simultaneous biting with the mandibles Adlerz finds to 

 puncture the skin at least at a point near the hind coxae, where the 

 ovum is subsequently laid in such position that the head of the young 

 parasite is directly against the ruptured surface and its nutrition thus 

 facilitated. 



Adlerz also observed cases in which the Methoca attacked the 

 larva down its burrow, and has evidence that here also the procedure 

 is very similar ; but it is interesting to note that she will use various 

 methods to tempt the larva to come up to the opening. It would 

 seem from the fact that when the larva is attacked outside the burrow 

 the sting in the throat is omitted, tliat this latter is essential to the 

 preparation of the victim for the offspi-ing of the parasite, and that, as 

 it produces general relaxation, it reaches, not the ganglia, but the cir- 

 culatory system. The subsequent stings are undoubtedly in the thoracic 

 ganglia. He further suggests that the external form of the ? Methoca 

 is specially adapted to enable it to escape injury f/om the embrace of 



D 



