THE CANADIAN ENTOMOLOGIST. 167 



Head and body colour as before. 



The bristles of the dorsal rows have ceased to be a conspicuous 

 feature of the ornamentation ; they are now but slightly curved and only 

 longer than the other bristles from the third to the eighth abdominal 

 segments. The entire surface above the substigmatal line is thickly 

 studded with short bristles and the egg-shaped processes which first 

 appeared in the preceding instar. These processes are very generally 

 scattered over the surface, and are in all respects the same as in the third 

 instar. 



The mid-dorsal area is dark green from the underlying blood-vessel. 

 White lines as before, except that the two upper ones are fused into one 

 band ; all are faint. 



The thoracic shield is a shallow, somewhat diamond-shaped pit. 



Length, 5 mm. to 6.5 mm. Average of 27 caterpillars, 5.76 mm. 



Fifth Instar. — The segments are only slightly arched. 



The bristles of the dorsal rows are very slightly curved backwards, 

 and are progressively longer proceeding caudad, from about the second to 

 the seventh abdominal segments, where they extend a little beyond the 

 other bristles. The longest bristles are in the frontal fringe and on the 

 first thoracic segment between this fringe and the diamond-shaped pit of 

 the thoracic shield. The egg-shaped processes are thickly scattered all 

 over the surface, except on the venter. 



The white lines are present now as two very faint bands, separated 

 from each other and the substigmatal line by a faint, wavy, green line. 



Length, 8 mm. to 10.5 mm. Average of 26 caterpillars, 8.9 mm. 



Mature Caterpillar. — The shape and colour are very much as before. 



The head is almost colourless, but it may assume a very faint brown 

 shade. 



Dorsal bristles as before. The longest bristles are on the first thoracic 

 and the anal segments. The egg-shaped processes and short bristles 

 thickly clothe the surface, as in the preceding instar. 



The white bands are more plainly marked in some specimens than in 

 others, and on very close examination are seen to be made up in reality 

 of four white lines very slightly separated by the green. 



The thoracic shield is a diamond-shaped pit, as before, but in addition 

 there is a curved crease-like extension on each side ; near each of the side 

 angles of the pit is a tubercle bearing a fairly long slender tentacle-like 

 process. 



Length, 14.5 mm. to 16 mm. Average of 7 caterpillars, 15.14 mm. 



