48 



Marvels of Insect Life. 



Photo by] 



[A . E. 



Butterfly. 



1 ongc, F.E.S 



Black-veined White 



One of our rarest butterflies as a British-bom Insect ; but our resident • i i i n • 



race is sometimes supplemented by visitors from abroad. The photograph OptCra. aCCOmpanieQ thc DUttertllC 



and a tine beetle flew on board. . 



thc deck of the Beagle when she was 

 ten miles out from the coast of South 

 America. Darwin says : " Vast 

 numbers of butterflies, in bands or 

 flocks of countless myriads, extended 

 as far as the eye could range. Even 

 bv the aid of a telescope it was not 

 possible to see a space free from 

 butterflies. The seamen cried out 

 ' it was snowing butterflies,' and 

 such in fact was the appearance. 

 More species than one were there, 

 but the main part belonged to a kind 

 very similar to, but not identical 

 with, the common English clouded 

 yellow. 1 Some moths and hymen- 



shows an individual that has just emerged from the chrysalis condition, 

 and is one-third larger than life size. 



The day had been fine and calm, and the one previous to it equally so, with light and 

 variable airs. Hence we cannot suppose the Insects were blown off the land, but we 

 must conclude that thev voluntarily took flight. . . . Before sunset a strong breeze 

 sprang up from the north, and this must have caused tens of thousands of the butter- 

 flies and other Insects to have perished." Captain Fitzroy estimated that this 

 assemblage occupied a space not less than a mile in width, several miles in length, 

 and two hundred yards in height. 



The painted lady^ is a species one of whose homes is in North Africa, but it 

 appears to thrive so exceedingly that there is too little room or insufficient food for 

 its progeny ; so vast swarms of the butterflies leave home and visit various countries, 

 where they lay their eggs. In some years the butterfly is exceedingly common here 

 in August and September, but these are not visitors. They are the British-born 

 progeny of the immigrants who arrived here in May or June, and left their eggs 

 upon our thistles. These in turn lay eggs, which hatch soon after, but few of these 

 autumnal caterpillars are able to complete their development ; so that, but for the 

 visitors from abroad, the painted lady would be very rare as a l^ritish butterfly, 

 and might altogether disappear from our list. 



My. J. Piatt Barrett has recorded the regular annual passing of what lie describes 

 as " clouds " of black-veined whites ^ and large garden whites over Sicily, always 

 flying westward. 



Other species of butterflies, no doubt, get accessions from timi' to time in the same 

 way ; just as certain rare hawk-moths are occasionally in comparative abundance 

 here. In the latter cases there is not the same room for surprise, because their 

 wings and stout bodies appear to be much better fitted ior flights of endurance. 

 Beetles, bugs, dragon-flies, and other Insects also perform these long migrations. 

 Mr. W. H. Hudson has described the periodical swarms of the larger dragon- 

 flies that pass over Patagonia and the pampas, flx'ing in advance of (not 

 1 Colias edusa. 2 pynimeis carilui. •' .\i)oria craUcgi. 



