NOTES ON PODAGRION PACHYMERUM. 265 



mature ootheca. I am not in a position to confirm or contradict 

 Xambeu's observations on the finding of the parasites under the 

 Mantis wings (though there is some doubt as to the identity of 

 his species ; see Bull. Ent. Soc. France, ser. 5, vol. viii. 1878, 

 p. clxiii.), but the explanations given are, at least, unnecessary 

 and improbable.* 



Giardina {I.e. p. 317) also states that this parasite usually 

 infests only one side of the ootheca, and that frequently the 

 eggs on one side are all parasitized, while those on the other 

 side were not attacked. In the specimens which I have examined 

 there were individual parasites on both sides ; sometimes only 

 one or two in a compartment, but more usually all the eggs in 

 one compartment were attacked. I can, however, confirm this 

 author's interesting observation that the pupae of the Podagrion 



Fig. 2. — Podagrion jpacliymcni-m laying eggs in Mantis ootheca, x 18. 



in the Mantis eggs have their head directed to the tail end of 

 the egg. It is possibly for this reason that they do not make 

 use of the exit passages already prepared for the use of the 

 young Mantids, but instead bore their way through the walls of 

 the ootheca to the exterior. 



On June 13th the Mantid larvae began to hatch in numbers, 

 all emerging in two or three days. Between July 13th and 20th 

 about a dozen more Podagrion emerged, all of which were 

 females. These would appear to be from eggs laid by the first 

 brood six weeks before. The fact that they were all one sex 

 may have been due to pairing not having taken place in cap- 

 tivity, and the eggs having developed parthenogenetically into 

 females, as is the case with many other insects. 



Specimens of Podagrion pachymerum were also bred by P. A. 

 Buxton from ootheca of Mantis religiosa found in Algeria and 



^' Since writing the above, I find that A. Giraiilt has (Ent. News, 

 Philadelphia, 1907, xviii., p. 107) described shortly the egg-laying of 

 Podagrion mantis, a parasite of the American Stagomantis Carolina. He 

 also found that the parasite had no difficulty in piercing the ootheca with its 

 oviuositor. 



