•P*^ AND ^^^^ 



JOURNAL OF VARIATION. 



Vol. VIII. No. 5. July 1st, 1896. 



The Hybernating stages of British Butterflies. 



By J. W. TUTT, F.E.S. 



Of the 65 butterflies considered as British by Newman, in his 

 British Jhittcrfiit's [i.e., excluding Ari/i/nnis niohe and Parnassins apallo) 

 he gives, on p. 17, the names of 42, the hybernating stage of which has 

 been " ascertained beyond all possibility of doubt." This leaves 23, 

 the hybernating stage of which were in doubt. Of the 42 about 

 which no doubt then 1 1871) existed, there are seven certainly wrong, 

 and of one [(Jhriji^Dphanus (iispar) the hybernating stage has never been 

 determined by observation, although the logical sequence of events 

 would suggest that Newman is correct. 



In order to correct some of the errors into which NeAvman had 

 fallen, and to add fresh information. Fitch published, in 1879 {Ent., 

 xii., pp. 1-4), a paper on the " Hibernation of British butterflies." He 

 makes one very grave error (connected with Aiyi/nnis adippc), and 

 also takes it for granted, like his predecessors, that FurainciH can'kii 

 hybernates as an imago. Besides these, he queries the stage in which 

 no less than 12 species pass the Avinter, and giyeBNoDiiades i>rmiciri/ns£hs 

 " unknown." 



Since then the hybernating stage of the whole of these has, been 

 satisfactorily determined, except so far as relates to Chnjsoiilianmdispar 

 and Li/caena avion. With the' exception of the verification of the stage 

 in which Everes ar///rt(/t'.s' hybernates, and the verification (or otherwise) of 

 the statement made by Hawes relative to Thi/iaeUrns tJiaui/ia!<, we .may 

 consider that the hybernating stage of all our other British butterflies a^-e 

 now known. The stage in which 0. dispar, L. arion and E. ■an/iades 

 hybernate is more likely to be determined by European collectors, but 

 British collectors should be able to clear up the doubt surrounding 

 T. tJiaimias. 



Newman stated {Biit. Bxitu., p. 10) that ; — " It is a most interesting 

 fact, and one that cannot be too strongly impressed on the memory, 

 that all the individuals composing one species ' of butterfly always 

 hybernate in the same state : each adheres strictly to the practice of 

 its species." Fitch says : — " The hybernation of a species is strictly 

 constant. A certain larva, even from the same ', batch of eggs, will 

 occasionally feed aAvay from its brethren, and appear as an im.'igo |in 

 the autumn, while the normal habit of the species is to hybernate in 

 pupa or even in larva, as the case may be. Agciin,, when May individuals 

 pupate together it sometimes happens that some ; q,,re. pprf eotecl pye- 



