342 THE ENTOMOLOGIST. 



NOTES ON THE EARLIER STAGES OF THE SECOND 

 BROOD OF POLYOMMATUS [LYCENA) ARGIOLUS^ 



By Robert Adkin, F.E.S. 



While staying at Eastbourne in August last I chanced to 

 come upon a iem.Q.\e Polyommatus argiolus in the act of depositing 

 ova on heads of flower-buds of ivy ; subsequent search revealed 

 eggs in considerable numbers, and later on the resultant larvae. 

 I was thus enabled to follow the life-history of the autumn 

 brood under absolutely natural conditions, from the laying of the 

 egg till the pupal stage was reached, of which the following is a 

 brief account : — 



At the time when the butterflies of the second brood are on 

 the wing, the flower-buds of the ivy are still young and form 

 compact heads. The butterfly, having selected one of these 

 heads, settles upon its top, closes her wings over her back, and, 

 bending her abdomen down and round underneath the buds, 

 affixes an egg to the under side of one of the slender single bud- 

 stalks. In about a week the eggs hatch. The young larva, 

 which in colour matches the buds very closelj^, rests on the bud- 

 stalk with its anterior segments, which completely cover its 

 head, pressed closely against the bud, and looks so exactly like a 

 slight swelling of the upper part of the stalk as to make detection 

 a matter of great difficulty, even with the aid of a fairly powerful 

 lens. Throughout its life the larva is very sluggish in its habits, 

 seldom leaving the head of buds on which it is hatched, so long 

 as sufficient food remains for its nourishment, or occasionally 

 when about to change its skin. It appears to feed only at night, 

 and its manner of feeding, which is the same throughout its life, 

 is to eat a round hole through the outer shell of a bud, and 

 pressing its head forward through it to clear out the soft inside 

 of the bud. In from four to six weeks it is full-fed ; it then 

 quits the buds, and attaches itself by slender silken threads to a 

 leaf, and in a few days becomes a pupa, in which state it parses 

 the winter. Although there is an amount of recorded evidence 

 that the larva will take other foods, the peculiar resting habit 

 and manner of attacking the flower-buds suggest very strongly 

 that the only natural pabulum of the later brood is the ivy 

 flower-buds, and the early brood would find the flower-buds 

 and young green berries of the holly similarly suitable to their 

 habits. 



-'' Abstract of a paper read before the South London Entomological and 

 Natural History Society, Nov. 12th, 1896. 



