206 THE ENTOMOLOGIST. 



existing literature on the metamorphoses of Tabanidae, and details 

 those of Tabanus quadrinotatus (12). 



Banks's revision of the Tyroglyphidae i2) is a valuable contri- 

 bution to the knowledge of the difficult "cheese-mites" and 

 "sugar-mites." Soar deals with the relation of Hydrachnids 

 (28) to their parasitism on aquatic insects. 



NOTES ON THE GENUS EUPITHECIA. 

 By Louis B. Prout, F.E.S. 



(Continued from p. 175.) 



Another question raised by Mr. Dadd in the same place 

 (Ent. Rec. xviii. 259) concerned the innotata group (innotata, 

 Hfn., fraxinata, Crewe, and tamarisciata, Fit.), and although I 

 do not know that I have any fresh light to throw on these, 

 a survey of what is known may prove helpful. Mr. Tutt {loc. 

 cit.) rightly girded at the German entomologists for undis- 

 criminatingly using "var. fraxinata, Crewe," for the second 

 generation of innotata, Hfn., whereas in Britain fraxinata is 

 single-brooded, hibernating as a pupa ; but the question of 

 possible specific identity cannot be summarily dismissed on this 

 ground. It has been definitely ascertained that larvae from the 

 early brood of innotata will feed on ash and other leaves (see 

 below, and compare the case of E. virgaureata, to be discussed 

 later), and it has also been ascertained that there is occasionally 

 a second brood of fraxinata in England, and that the larvae 

 obtained from this will accept mugwort as a food-plant (vide 

 Crewe in Ent. Annual, 1865, pp. 124-5). It is therefore not 

 inconceivable that the regular economy further south than with 

 us is to alternate, according to the season, between the flower- 

 feeding and tree-feeding habit, but that in Britain, being practi- 

 cally driven into single-broodedness, it has split up (or is in 

 course of doing so) into two races, one favouring each pabulum. 

 It seems to me that ash-feeding summer larvae, if deprived 

 by climatic conditions of the autumnal emergence of their 

 imagines, would concurrently be deprived of the later autumn 

 mugwort larvae, and an ash-feeding race could be established ; 

 while a belated emergence from hibernated pupae (say, about 

 Midsummer instead of in April and May, as in Germany) might 

 at the same time bridge over the period in which a tree-feeding 

 habit would have been necessary, and result in the laying of 

 eggs on Artemisia, &c, which might by that time be sufficiently 

 advanced to be serviceable. I know that all this is highly 

 speculative, and that even if it be in accordance with fact it does 

 not absolutely settle the question whether it were more expedient 



