65 



FORFICULA AURICULARIA. 

 By H. H. Brindley. 



Forficula aurieularia (slightly magnified). 



The individuals in the photograph reproduced are a female 

 and two males, the latter being as regards length of callipers 

 " high " and "low," following the terminology of Bateson (Proc. 

 Zool. Soc. London, Nov. 15, 1892, p. 585). They were obtained 

 in September, 1913, on the uninhabited islet of Rosevear in the 

 Scillies, situated about two miles east of the Bishop Rock. This 

 islet swarms with earwigs which are mostly large bodied, while 

 the " high " male is much commoner than the " low." Rosevear 

 was inhabited from 1850 to 1858 by the workmen employed to 

 build the present Bishop Lighthouse. Is it possible that the 

 remarkable abundance of earwigs, on an islet whose features are 

 mainly masses of granite and a vegetation of sea-pink and giant 

 mallow, is related to this human settlement of half a century 

 ago? On Round Island, the northernmost islet of the Scilly 

 group, earwigs are also very numerous and seem to feed chiefly 

 on the kitchen refuse thrown "over cliff" by the light keepers, 

 the only human inhabitants. 



The specimen illustrated has callipers 12*25 mm. in length, 

 and thus markedly exceeds that taken by Mr, P. M. Bright at 

 Freshwater, Isle of Wight, in 1910, and illustrated in the 

 ' Entomologist,' June, 1911, p. 209. In Mr. Bateson's collection 

 of 1892 in the Farn Islands six specimens had callipers 9'Omm. 

 long, and in 1907 and 1908 I obtained four from the same 

 locality with callipers 8'75 mm. In a collection made on Round 

 Island in 1911 I found thirty-four males with callipers 10 mm. 

 or more, among which the highest had the value ll'O mm. 



ENTOM. FEBRUARY, 1914. F 



