POLIA CHI. 15 



POLIA CHI. 



Plate LXXXVIII, fig. 3. 



On September 14th, 1869, Mr. Longstaff, then at 

 Forres, kindly sent me a few eggs laid by a female of 

 this species ; these began to hatch on April 11th, 1870, 

 and continued at the rate of about one or two per 

 diem until the 22nd. The larvae, when young, fed 

 chiefly on Bumex crispus, and occasionally on some 

 other low plants ; they at that time were not particular 

 in their diet, for they seemed to welcome any change 

 given them ; but after two or three moults they began 

 to show a decided preference for sallow and osier, 

 and on this food, towards the last, they were entirely 

 kept, until they became mature one after the other, 

 from May 20th to June 5th ; the perfect insects 

 appeared from August 10th to 21st. 



The egg of Polia chi is hemispherical in form, or 

 rather elliptical at top and flattened beneath at its 

 greatest diameter ; deeply ribbed and reticulated ; 

 when first laid it is yellowish, and in a few days turns 

 greyish-brown, and about a week before hatching a 

 broad zone of flesh colour appears below, while the 

 upper part is a rich crimson-brown ; at this time, in 

 respect of colour, variations occur, — some of the eggs 

 have a narrow zone of blackish at a distance of two- 

 thirds from the base, while the top is irregularly 

 blotched with this colour. 



The young larvae, when first hatched, were pale 

 olive-greenish, the large head pale brownish with 

 distinct black dots and hairs ; but they became in a 

 couple of days rather bluish-green. By April 23rd 

 the most forward had become half-an-inch in length, 

 very slender, and of a full deep green colour, with 

 the lines and also the dots paler green; by May 15th 

 the biggest had grown to one inch in length, still 

 slender in proportion, and rather less deep in colour, 

 which, by the 19th, had changed to a yellow-green, 



