ON WALKER'S JAPANESE ICHNEUMONID^. 131 



p. 103, notes it as occurring abundantly both on the Continent 

 and in Britain ; and, further, he there suggests, from the habits 

 of allied species, that it may prey upon Syrphid larvae. The 

 following extract from his description of the species may be of 

 interest : — " We know nothing of its economy, though that it 

 preys upon Syrphid larvse is rendered probable by my capture of 

 a female on 28th June, 1903, investigating the green and un- 

 opened buds of Heracleum, covered with Aphis hieracii, Kalt." 



The periods of occurrence of the Syrphid and its parasite as 

 adults practically coincide, both being on the wing from May to 

 September. The Syrphid is double-brooded, the insect hyber- 

 nating in the larval state, pupating in March, and the adults 

 emerging in the beginning of May. The eggs laid by this 

 generation give rise to the adults which are seen on the wing in 

 September, the summer brood passing through its development 

 much more rapidly than the winter one. The larvae which hatch 

 from the eggs of this second generation of flies are those which 

 hybernate, and from their pupae the adults of late spring and 

 early summer emerge. On making investigations as to the food 

 of the larvae of P. albimanus, I found that they were preying 

 upon Pterocallis Mice, Linn., a species of Aphis infesting the 

 lime-trees (Tilia grandiflora, Ehrhart) in the grounds attached 

 to the Experimental Laboratory. 



In addition to H. dimidiatus, I also succeeded in rearing 

 another species of this genus, the host being the same as in the 

 previous case (P. albimanus). This latter was identified by Mr. 

 Morley as being Homocidus tarsatorius, Panz. The date of its 

 emergence from the parasitized pupa was Sept. 12th, 1912. 



ON WALKER'S JAPANESE ICHNEUMONLM1. 



By Claude Morley, F.Z.S. 



In " Descriptions of some Japanese Hymenoptera, by Francis 

 Walker, Esq." (' Cistula Entomologica,' i. 1874, pp. 301-310), 

 twenty-two species of Parasitica and two Cynipidse are shortly 

 and quite inadequately diagnosed as new by its author, excepting 

 one, of which he states the alternate sex had been brought 

 forward by Fred. Smith during the same year in his ' Descrip- 

 tions of New Species of Tenthredinidse, Ichneumonidee, Chrysi- 

 didae, Formicidae, &c, of Japan.' No more definite localities are 

 indicated than Japan. I shall here try to throw some light 

 upon the systematic position of these insects, which have hitherto 

 been but an incumbrance to our catalogues, though the dis- 

 coloured state and the deplorable setting of the specimens, which 

 were doubtless first preserved in spirit, greatly hamper such an 

 attempt, since they are all gummed (often over their very 



