DISTRIBUTION OF LEPIDOPTERA. 61 



without immioTation. But I cannot call to mind any permanent resi- 

 dent in our islands that is unable to withstand frost, though it ou^ht 

 to be possible for such a species to exist in the Scilly Isles or in the ex- 

 treme south-west of Ireland, Other immigrants such as A. lathunia and 

 7). (jalii do not find even the most favoured spots in this country suf- 

 ficiently Avarm to enable them to complete the cycle of their trans- 

 formations within the year. It is characteristic of immigrants that 

 though most frequently seen on the coast, they may spread over the 

 whole country, as is evidently the case with C. rdiim and P. rardiii. 



There is one immigrant that very much puzzles me. It is not, 

 perhaps, entirely apposite to the paper, yet I cannot pass it by, as I feel 

 sure, if we knew why Kuvanesfta antiopa fails to establish itself in our 

 islands, we should have an answer to some of the more puzzling ques- 

 tions of insect distribution in Britain, including some aspects of the one 

 before us. In Europe, it extends from Naples in the south to the 

 extreme north of Lapland, where I saAv it in lat. 70deg. last summer 

 (1898) on the same ground as Antlirucera e.vulan>i. It has also a very 

 wide distribution in other quarters of the globe. Its food-plant is 

 abundant enough in our islands. The only guess I have been able to 

 make is perhaps a very wild one ; it is that our winter climate is 

 neither hot enough nor cold enough for it. If it were hotter K. antiupa 

 could be continuously brooded, as it probably is in the extreme south 

 of Europe ; were it colder it could hibernate sufficiently. It is a species 

 that goes into hibernation very late, and desires a very low tempera- 

 ture. With us it would have in spring and autumn to do what I have 

 seen P. cardiii doing in the south of France for weeks together in the 

 winter, showing itself for a short time on sunny days, and neither 

 hibernating nor progressing with its life-history. E. antiopa cannot 

 probably behave in this way, owing to the hibernating tendency, which 

 appears hardly to exist in P. cardui. 



Epunda Uchenca is probably a truly littoral species. It is found on 

 the east coast as far north as Yorkshire, and therefore might occiu' 

 inland were temperature the only difficulty. Its food-plants, at least 

 in captivity, are varied enough, and none of them are truly littoral 

 species. I must leave this species for a fuller knowledge of its Conti- 

 nental distribution, which, so far as I know, is not inland. 



La^utcampa trifulii affects our south and west coasts, and does pene- 

 trate a little inland. I think it probably belongs to the group that 

 makes some winter progress owing to its ability to be active in our coast 

 winter temperature. So far as I can learn, it hibernates on the 

 Continent as a young larva ; in England, at least sometimes, the eggs 

 do not hatch till late winter. This may also be the case in its more 

 northern Continental stations, which range north of the mean annual 

 isotherm of our south coast, hence it ought not to require much winter 

 assistance. The young larv;y eat during the winter or as early in spring 

 as they can. I have a doubt whether the eggs not hatching till after 

 winter sets in be not due to the conditions being too cold for them, and 

 whether such an event naturally occurring would not be the first step 

 towards the extinction of that brood. However this may be, I have no 

 doubt that L. trifulii in England requires to be active during the winter 

 in order to get through its changes in a year. 



In connection with L. trifulii, it may be convenient to refer to the 

 climate of the Flint and Cheshire coast. Llandudno has a winter 



