LEPIDOPTERA, ETC., AT SCOTTISH LIGHTHOUSES 129 



LEPIDOPTERA (MOTHS) AND OTHER INSECTS 

 AT SCOTTISH LIGHTHOUSES, CHIEFLY IN 

 THE FORTH AREA. 



By William Evans, F.R.S.E. 



(Continued from page 63.) 



Among Dragon-flies similar migratory movements are of 

 frequent occurrence. Two British species, Libcllula depressa 

 and L. qnadrimacidata, furnish notable instances. We read, 

 for example, of "cloud-like swarms" of Dragon-flies chiefly 

 of the former species that occurred over a large area in 

 Germany in the end of May 1839 ; of a column of the former 

 about 60 ft. wide and 10 ft. deep that, moving with the speed 

 of a trotting horse, took the greater part of a day in June 

 1852 to pass over Konigsberg ; and of an "extraordinary 

 flight" of the latter which was witnessed at Malmo, in 

 Sweden, on 24th to 26th June 1883. L. quadrimaculata is a 

 frequent visitor to the island of Heligoland, "millions" 

 making their appearance all of a sudden, and as suddenly 

 taking their departure (Gatke). As regards our own coasts, 

 mention should be made of the " flock " of this same species 

 that settled on the Swin Middle light-vessel, off the mouth 

 of the Thames, late in the afternoon on 28th June 1888; of 

 the hundreds seen flying around Dover pier on 6th June 

 1889; of the immigration observed at Berwick in June 1900; 

 and of the " extraordinary migration " observed in North 

 Wales on 1st and 2nd June 191 1. 1 In the last-mentioned 

 year Britain was visited (not, however, for the first time) by 

 another migratory Dragon-fly, Sympetrum fonscolombii, some 

 of the individuals of the flight reaching the Forth (Isle of 

 May, etc. 2 ) on the east, and the Clyde (Arran 3 ) on the west ; 

 while so recently as 12th October last a specimen of the far- 



1 Manchester Guardian of 16th June 191 1. 



2 W. Evans, Scot. Nat., January 1912, p. 12. 



3 K. J. Morton, ibid., January 1914, p. 22. 

 30 R 



