10 NATURAL HISTOHY SOCIETY OF DUBLIN. 



Wright, December, 1865 ("Proc. Nat. Hist. Soc. of Dublin," vol. v., p. 7), 

 placing on record three new Irish localities for this insect — Co. Dublin, 

 Co. Down, and neighbourhood of Belfast, and giving much information 

 on the geographical range of this insect ; and another by Mr. Andrews, 

 in January, 1866.— (0p. cit., p. 20). 



It has been observed that there are some Lepidopterous insects 

 whose appearance in any considerable number in a given year is un- 

 certain, while periodically there is an unusual abundance of them. 

 Among those most subject to a periodic scarcity and plenty are> Colias 

 edusa and hyale, Sphinx convolvuli, which, in the year 1846, was in 

 England captured on the wing in hundreds (Stainton's Man., vol. i., p. 

 82), Cynthia cardui, and A. sancia (the pearly underwing). The explana- 

 nations that have been offered of this irregularity of appearance are, that 

 the eggs or pupaa lie dormant until a favourable season occurs for their 

 development ; that if the weather be unusually severe at the usual time 

 for the egg hatching, the development of most of the eggs will become 

 latent, and they will wait over till a more favourable season, when there 

 may be, in consequence, a double or treble brood ; others think that 

 the period of maximum mortality among young Lepidoptera is when 

 they are small larvse, having just left the egg, and that it is the occur- 

 rence of heavy rains at this time which causes the greatest diminution 

 in their numbers. 



Towards the end of September I took at sugar Agrotis sancia and 

 Agrotis lunigera (the crescent dart) ; of the former, a dozen specimens, 

 which exhibit a good deal of variation in their tints and markings. 4th 

 September I was sent a fine larva of Acherontia atropos (death's head 

 moth), almost full fed ; it had been found in a garden among cabbages ; it 

 ate potato leaves voraciously till the 6th, when it left off feeding ; its co- 

 lours lost their brightness, and the skin over the anterior segments became 

 puffed-up, giving it a bloated, dropsical appearance. I was continually 

 watching the larva, and distinctly observed it working with its mandi- 

 bles at the skin of the distended parts till it cut it, letting out a 

 quantity of water, which removed the dropsical appearance, and notably 

 reduced its bulk; the next day (7th September) it buried itself in clay, 

 with which I had filled the bottom of a breeding cage ; having eight 

 days afterwards to disturb the clay, I found the large brown chrysalis 

 in its capacious egg-shaped clay coccoon. Superstitious feelings with 

 regard to this curious caterpillar prevent its being more frequently 

 obtained. My friend, Mr. Graves, told me that it is to this day in the 

 county Kilkenny called by the peasantry the murrain, from an impres- 

 sion that it gives cattle the murrain, by stinging them in the nose with 

 the caudal horn ; and the remedy they adopt is to take the larva and 

 put it into a hole made in an ash tree, the hole they close up with a 

 plug of wood. Mr. Graves saw this done in the county Kilkenny when 

 he was a boy, years before the potato blight had come to this country, 

 which misfortune has since been attributed also to this larva — perhaps 

 from the larva feeding on the leaves of the potato and the chrysalis 



