400 THE CANADIAN ENTOMOLOGIST. 



THE LARVA OF NEOARCTIA BEANII, NEUM. 



BY ARTHUR GIBSON, OTTAWA. 



On May 19th, 1908, the late Dr. Fletcher, received from Mr. N. B. 

 Sanson, of Banff, Alta., two arctian larva?, which had been found on 

 Sulphur Mountain. These larvae were given to the writer. Both speci- 

 mens moulted on May 22nd, but one died immediately afterwards. The 

 plant Antennaria racemosa was sent with them. Antennaria rosea, some 

 plants of which (from British Columbia) were growing on the Experimental 

 Farm, was offered to the larvae, as well as plantain, willow, grass and 

 dandelion. The only food which the remaining larva would eat was 

 plantain. This it ate readily. On May 28th the following description 

 was taken : 



Mature larva. — Length, 32 mm. Head, 2 mm. wide; somewhat 

 quadrate, only slightly depressed at vertex, jet black, shining ; hairs on 

 face black. Dorsum and sides of body, above spiracles, dull green, densely 

 mottled with brown ; skin on lower portion of sides, enclosing tubercles 

 iv, v and vi, almost wholly orange ; venter greenish. An indistinct, dull 

 orange, dorsal stripe is present. Tubercles all black and shining, bristles 

 very faintly barbed. Tubercle i as large as ii, iii and iv, which are all 

 about the same size. Bristles from tubercles i and ii all black, from iii 

 black, with a few white ones intermingled. From lower half of iv, and 

 from v and vi, the bristles are bright rust-red ; from vii and viii dark 

 rust-red, spiracles black. Thoracic feet black, shining ; plates on prolegs 

 dark shiny brown. 



The larva did not feed on May 28th, and before evening it had spun 

 a few threads of silk. By the morning of the 30th it had changed to the 

 pupa. The cocoon was simply a very thin covering of whitish silk. The 

 moth emerged on June 15th. 



Pupa. — Length, 21 mm.; width at widest part, 5.5 mm. Colour 

 dark bluish-black; very faintly pruinose ; shining, particularly at folds of 

 abdominal segments. Abdomen bears sparsely, very short, thick, reddish 

 hairs. Spiracles black. Cremaster round, dark reddish-brown, shining, 

 terminating in a bunch of about 18-20 reddish bristles of varying lengths, 

 each with a distinct tendril-like curve at the tip. 



In the Canadian Entomologist, June, 1891, p. 124, a short 

 description of the larva is given by Mr. Bean. Since this note appeared, 

 Mr. Bean tells us that he found a further larva in the middle of July, 1893, 

 at about 7,000 feet altitude, on Mount St. Piran. This larva produced a 

 male moth on Aug. 20th. 



November. 1909 



