1 32 THE SCOTTISH NATURALIST 



interesting to note that the hop-aphis did much damage in 

 the south of England in 1869. What appears to have been an 

 immigration of another small beetle a species of Gallcruca 

 on the north coast of Scotland was noted by Romanes in 

 April 1870. The Moray and Cromarty Firths were, he 

 states, covered with the beetles ; they were seen floating 

 by millions on the sea, and were afterwards cast upon the 

 shore in heaps by every tide. 



Instances of Diptera (two-winged flies) appearing in 

 vast swarms are also on record. Curtis observed that 

 certain Syrphids (S. ribesii, S. pyrastrz, and 5. selenitica were 

 named) sometimes make their appearance in myriads on 

 the sea-coast, all flying in one direction. On one occasion 

 " they quite covered the fishermen's boats at sea off Broad- 

 stairs." The " swarming " habits of Ants and certain other 

 social Hymenoptera are well-known, while on the coast at 

 Deal, etc., immense flights of a species of Sawfly have been 

 recorded. 



Allusion should be made to the great numbers of insects 

 largely belonging to lowland species, met with by Dr Bruce 

 on the snow-covered plateau at the top of Ben Nevis (see 

 papers by Thornley in Ann. Scot. A T at. Hist, for 1896). In 

 North America the congregating of insects on the summits 

 of lofty mountains has also been remarked upon. 



Having shown that many moths and other insects possess 

 migratory propensities, and as a matter of fact do make 

 migratory flights often of great extent, references may now 

 be given to published records of occurrences at lighthouses 

 on the coasts of Great Britain and Ireland. No systematic 

 observations have, so far as I am aware, ever been published 

 only scattered records, and few even of these, based on 

 captures of a more or less casual nature. The few allusions 

 to insects contained in the British Association reports on 

 the migration of birds, have been referred to by Canon 

 Fowler in the Ent. Mo. Mag. for 18S8 (vol. xxiv., p. 204). 

 What value they possess lies rather in what they suggest 

 than in any data they supply. Only two species are definitely 

 named, the Death's-head, of which one was caught at 

 Hasbro' Light-vessel, off the coast of Norfolk, on 7th June 



