Zoology?^ NATURAL HISTORY OF VICTORIA. {^Imtcts. 



The larva and pupa resemble those of P. Cardui very nearly, 

 but are of smaller size. The habits are very much alike ; our 

 form, like the European one, being singularly robust and active, 

 flying about even in windy weather, and found nearly all the year 

 through, but most numerous in the hotter months from September 

 to March, and more commonly than any other species, especially 

 where the accidentally introduced Cape Weed {Crijptostemmon 

 calendulacea) abounds, as for this it forsakes all other plants.* 

 I note that that excellent observer, Mr. Trimen, does not record 

 this amongst the plants eaten by the larvae of the true P. Cardui 

 at Cape of Good Hope. 



In the latter end of September and beginning of October of last 

 year this Butterfly appeared in extraordinary numbers for two or 

 three Aveeks, accompanied by a day-flying Moth, Agrotis spina, 

 almost darkening the sky with their general flight towards the 

 south-east, covering the gear and decks of ships many miles out 

 at sea, and filling the air on land from the northern parts of the 

 colony down south to Melbourne. They poured into Gippsland in 

 such quantities as to spread consternation amongst the settlers, 

 who inundated me with letters inquiring whether their crops or 

 orchards or vineyards would be destroyed b}^ the larvae expected 

 to follow. I was glad to be able to assm-e them that the only 

 likely damage would be to hated weeds. The newspapers 

 mentioned the stoppage of ti'ains in the tunnel on the Castlemaine 

 Railway, from the masses of bodies of these insects crushed 

 lubricating the wheels to such an extent that they could not bite 

 the rails as they turned, and came to a standstill until sufficient 

 supplies of sand could be sent. 



They frequently rest on the gi'ound or plants for a short 

 time, with the vrings expanded horizontally ; when sleeping or 

 resting for a long tinie the wings are brought together erect, 

 with the reddish part of the under surface of the anterior wings 

 concealed by the over-lapping of the hind ones ; and when resting 



" This curious change of habit in Victorian Insects, abandoning' their native food for some introduced plant on 

 which they thrive so much better as to become st'riltin;fly more abundant tlian before, has been remarlied upon in 

 our account of the AijarUla^ so destructive to the vine, isee Decade I., Plats 8. 



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