PROCEEDINGS, 1921 3X 



grayish stripes run the length of the body, separated by a black line of 

 equal width, each of the grayish stripes being outwardly edged by black 

 lines along the spiracles, and the black extends to the ventral surface, 

 so that practically, with the exception of the anal claspers and the skin 

 fold behind the head, the larva is striped on the dorsal area with lines 

 of black and gray, the median line being black. On May 16th length 

 5j/2 m.m. Head black; the front part of the fold behind the head gra}' 

 with a dark line behind it ; body striped as before, but the colours are 

 dirty green and grayish green. Larvae rather restless in their habits; 

 fed on the tender new growth of Douglas Fir. 



On 27th of May length 10 m.m. Head as before. The three pairs 

 of front claspers also jet black. Some of the larvae were still of a dirty 

 green as general tone, but others inclined to plum colour in the darker 

 stripes. The longitudinal lines still distinct, but instead of being about 

 equal breadth, the lighter lines have narrowed, leaving the dorsal central 

 stripe much wider, and also the stripe above, the light spiracular stripe 

 slightly wider, in proportion, than before. The dorsal stripe is lighter 

 in colour than the outer ones and is bordered (immediately adjoining 

 the white stripe) with darkec, and in this dark edge is situated a dot 

 on each segment. 



On 13th June length 18 m.m. The stripes very clearly defined and 

 colours more pronounced. General tone green (simulating the colour 

 of the old spines of the fir), with conspicuous yellow spiracular lines and 

 two other, narrower, light green lines. All the lines (stripes) have dark 

 purplish brown margins. To go more into detail, the central dorsal 

 stripe is broad, bordered by narrow dark lines, then a greenish white 

 stripe again bordered by a dark line throughout its length ; between 

 this and the yellow spiracular stripe, the narrow space is occupied by 

 aa irregular series of broken dark lines; these dark irregular and slightly 

 wavy lines (5 or 6) are continued all over the ventral area, the ground 

 colour of which is green. 



At this stage the head is green, with 14 dark spots. The anus also 

 has black spots. 



When eating the larva starts at the outer end of the fir-spine and 

 demolishes it across — not lengthways. 



On 3rd July length about 25 m.m. General markings not much 

 changed. Dark spots on head conspicuous. Broken dark lines on the 

 green background not so noticeable. 



On 6th July three or four of the most forward larvae had spun a 

 few strands of silk among the pine needles, each making a very flimsy 

 cocoon preparatory to pupating, and on the 7th had changed to a bright 

 green chrysalis with two white stripes down the back, and another 

 stripe on each side extending from the outer margin of the wing-case 

 to the tail. The wing-cases are also white with green veins. The 

 white areas of the wing-cases increase towards the time of emergence. 



