LEriDOPTERA, ETC., AT SCOTTISH LIGHTHOUSES 131 



readily suspect of exaggeration, of a great flight he witnessed 

 at Luxan, La Plata, during the voyage of the Beagle, must 

 be familiar to most of my readers. From time to time a 

 few locusts, probably in most cases belonging to the species 

 Pachytylus cinerascens, though usually recorded as P. migra- 

 toj'ins, reach the British Islands in the course of their travels. 

 In Scotland specimens have been got in the Border counties, 

 in the neighbourhood of Edinburgh, and as far north as 

 Aberdeen, Wick, and even Orkney. 1 



In other groups of insects manifestations of a migratory 

 impulse, though less frequently observed, are not wanting. 

 Among Coleoptera (Beetles) the Coccinellids or Ladybirds 

 supply some interesting examples, and it is possible to 

 argue that the vast " visitations " of these pretty little insects, 

 which are occasionally reported from the south-eastern 

 counties of England, are to be explained as immigrations 

 from the Continent. Some particulars of two of these 

 visitations, taken from accounts sent to The Times, will be 

 found in Staveley's British Insects, 1871, pp. 95-97. The 

 first took place in August 1847, when the Beetles "more or 

 less covered miles of ground in Romney Marsh, and a cloud 

 of them, miles in extent, resembling a long column of smoke 

 from a steamer, was, from the heights of Ramsgate and 

 Margate, seen hanging over the sea." Next morning the 

 coast was covered with them ; " five bushels were swept from 

 Margate pier, and Ramsgate harbour was in nearly the same 

 state," as was also Brighton during the two following days. 

 The other visitation occurred in August 1869, when "count- 

 less multitudes of the little red beetles " appeared upon the 

 coasts of Kent and Sussex. The numbers composing this 

 flight are described as "utterly inconceivable to those who 

 did not see them. They were most numerous close to the 

 shore tens of thousands perished in the sea near the land. 

 The beaches, piers, and houses near the shore were covered 

 by the swarms, and in many places the stieets and roads 

 looked as if strewn by dark red gravel." Aphides or " Green- 

 flies," which are themselves subject to migratory movements 

 on a laree scale, are the natural food of ladybirds, and it is 

 1 Cf. Ann. Scot. Nat. Hist., 1901, p. 28. 



