IMPERFECT SOCIETIES OF INSECTS. 295 



Asthelocust-eatingthrush {Tardus Gri/Uivorus) accompanies the locusts, 

 so the lady-birds {Coccinellcc') seem to pursue the Aphides ; for 1 know no 

 other reason to assign for the vast number that are sometimes, especially 

 in the autumn, to be met with on the sea-coast, or the banks of large 

 rivers. Many years ago, those of the Humber were so thickly strewed 

 with the common lady-bird (C. Septempundala'), that it was difficult to 

 avoid treading upon them. Some years afterwards I noticed a mixture of 

 species, collected in vast numbers, on the sand-hills on the sea-shore, at 

 the north-west extremity of Norfolk. My friend, tlie Rev. Peter Lathbury, 

 made long since a similar observation at Orford, on the Suffolk coast ; and 

 about five or six years ago they covered the cliffs, as I have before remarked, 

 of all the watering places on the Kentish and Sussex coasts, to the no 

 small alarm of the superstitious, who thought them forerunners of some 

 direful evil.^ These last probably emigrated with the Aj)hides from the 

 hop grounds. Whether the latter and their devourers cross the sea has 

 not been ascertained ; that the Coccinelte attempt it, is evident from their 

 aligiiting upon sliips at sea, as I have witnessed myself.* This appears 

 clearly to have been the case with another emigrating insect, the saw-fly 

 (Ai'/ialia centifolice) of the turnip.^ It is the general opinion in Norfolk, 

 Mr. Marshall informs US'*, that these insects come from over sea. A farn)er 

 declared he saw them arrive in clouds so as to darken the air ; the fisher- 

 men asserted that they had repeatedly seen flights of them pass over their 

 heads when they were at a distance Irom land ; and on the beach and cliff's 

 they were in such quantities, that they might have been taken up by sliovel- 

 fuls. Three miles inland they v> ere described as resembling swarms of bees. 

 This was in August, 1782. Unentomological observers, such as farmers 

 and fishermen, might easily mistake one kind of insect for another ; but 

 supposing them correct, tiie swarms in question migiit perhaps have passed 

 from Lincolnshire to Norfolk. Meinecken tells us, that he once saw in a 

 village in Anhalt, on a clear day, about four in the afternoon, such a cloud 

 of dragon-flies (Libclhdina) as almost concealed the sun, and not a little 

 alarmed the villagers, under the idea that they were locusts ^ ; several 

 instances are given by Rosel of similar clouds of these insects having been 

 seen in Silesia and other districts ®i and Mr. Woolnough of Hollesley in 

 Suffolk, a most attentive observer of nature, once witnessed such an army 

 of the smaller dragon-flies (Agrion) flying inland from the sea as to cast a 

 slight shadow over a field of four acres as they passed. A migration of 

 dragon-flies was witnessed at Weimar in Germany in 1816, and one far 

 more considerable, perhaps the greatest on record, May 30th and 31st 



1 Some such terrific idea would seem to have entered the snpient heads of the 

 authorities of one of the jirincipal towns of Berkshire, whicli in October, 1835, ac- 

 cording to the licadinrj Mercury, having had "a most formidable invasion of this 

 beautiful insect [lady-birds'] . . . the parish engines, as well as private ones, were 

 called into requisition, -with tobacco-fumigated water, to attack and disperse 

 them."[!!!] 



2 Mr. Curtis informs us that the aphidivoi-ous fUes (Scccva Rihesii, Pip-astri, &.c.), 

 like the lady-birds, sometimes appear in myriads on the sea-coast, all Hying in one 

 directioc, and not even avoiding objects that lie in their course. (Brit. Ent. 

 fol. 509.) 



3 Fn. Germ. Init. xlix. 18. ■* Philos. Trans, Ixxiii. 217. 

 5 Naturforsch. vi. 110. C jj, 135. 



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