154 BHITISH CICADA. 



are said to occur in one year. It was thought probable 

 that these insects passed the winter as pupae within 

 the bodies of their host, and that subsequently these 

 Diptera assumed wings to rove and invest other 

 Tettigidse in the foUowing spring. Conchisions were 

 come to that the dipterous insects preyed on the 

 Typhlocybidse ; but that the hymenopterous Aphelopus 

 was parasitic on them, and they form the sacs, which 

 are attached to the abdomen and sometimes to the 

 thorax of the host. 



Boheman had previously shown the parasitic habits 

 of Dryinus and Gojiatopus, and also that an economy, 

 similar to that described by M. Giard, obtained in 

 the dipterous gnat-like species of Piinmculus. Probably 

 the generality of the Pipunculidse are parasitic, and 

 prey chiefly on small Jassidte. The larva of Ateleneura 

 lies within the swollen abdomen of the Typhlocyha, 

 having its head turned towards the tail; tinally it 

 escapes from a rent of the dorsal part and falls to the 

 ground, before becoming a nymph. 



M. A. Giard admits a distinction between Typlilocyha 

 hippocastani and T. Boiiglasi of Edwards, both of which 

 insects feed on the horse-chestnut ; and remarks that 

 the first species is chiefly attacked by Aphelopus, whilst 

 the latter becomes principally ihQ^YQj oi Ateleneura. 

 The specific females of these Typhlocybidse can scarcely 

 be separated one from the other ; and it would appear 

 that sterility in this sex is chiefly shown by a partial 

 atrophy of such parts as the saw-apparatus, which is so 

 reduced in size and in strength^ as to make it in- 

 capable of cutting grooves for the eggs, should ova ever 

 appear. In the males, the penis appears to be the organ 

 most modified in its structure. A changed efficiency in 

 the testes has not yet been shown. This would most 

 satisfactorily prove a condition of sterility, or *' castra- 

 tion parasitaire." The difficulty, however, of an ade- 

 quate examination of these parts is fully recognized. 



It remains yet to be explained how the destruction 

 of Ateleneura is effected by the Aphelopus, for the latter 



