LIFE-HISTORY OF BRENTHIS FRIGGA. 81 



nately Mr. Main, not having my knowledge of the supposed 

 predilection of the larvae for Rubus, took a wider survey of the 

 food-plant question, and gave them, amongst other plants, 

 sallow, to which rather unlikely pabulum for a Brenthid they 

 took freely, changing into the second stage about a week after 

 emerging from the ova. 



On August 12th Mr. Main handed over to me three of his 

 larvae, which were then in the second stage, retaining himself 

 four, which comprised his remaining stock. Of the three larvae 

 which I had in charge two refused to feed further, and were 

 evidently prepared to hybernate at once. The remaining one 

 fed upon sallow slowly until August 25th, when it also ceased 

 to feed. 



Early in September I placed my larvae in a cool cellar to 

 pass the winter, but from the first I was doubtful of the treatment 

 being successful, for they commenced at once to shrink in size, 

 and in early October had disappeared from the sides of the 

 flower-pot in which they were placed, and to which they had 

 attached themselves. At the end of January I turned out the 

 pot, and found that the larvae were dead, and on communicating 

 with Mr. Main, he informed me that his larvae, which were kept 

 in the open air, had met with a similar fate. 



The egg is 1 mm. in height, '85 mm. broad. It has vertical 

 ribs, about twenty-four in number, which are irregular in 

 outline, and are crossed by numerous shallow transverse ribs. 

 The micropylar area is not distinctly separated from the sur- 

 rounding surface ; it consists of a number of shallow cells, not 

 noticeably depressed. The egg is highly glazed and opalescent ; 

 it is attached to the object it is deposited on by the female, and 

 is straw-coloured at first, becoming of a leaden hue shortly 

 before the larva emerges. 



The larva emerges by eating an irregularly shaped hole at the 

 side of the ovum near the apex. Immediately after emergence 

 it is 2*5 mm. long ; head jet black and highly glabrous, the 

 remainder of the segments are deep grey-green and very spiny ; 

 each segment is prominent in outline, and contains a row of 

 eight shining black tubercles, each of which emits three light- 

 coloured spines, which are in length about three times the 

 diameter of the tubercle. The head is thickly covered with 

 spines. 



In the second stage the larva has a much darker general 

 area, and the tubercles are much more prominent and produced 

 to a sharp point ; each tubercle emits a number of black spines 

 (ten or twelve). 



February 3rd, 1913. 



