Fii;. 8. 

 Work of P. rufipennis. Three stages in the development of the egg-tunnels. 



Fig. 9. 

 I. balsameus. Development of larval 

 gallery. 1, egg-niche; 2, egg- 

 packing; 3, chips and ex- 

 crement of larva, darker 

 in color; e.t., egg- 

 tunnel. 



C., -U^iyyyyx^L^- 



Fig. 11. 

 /. 'balsameus. Newly hatched 

 larva. 



Fig. 13. 



7. caelatus. From white 



pine. 



«■./. 



Fig. 10. 



Larch Ips. Under side 



of bark. 



Fig. 12. 

 The Larch Ips (24-V-lO). Under 

 side of the bark shown, with, 

 eggs in the pockets. 



7 E.S. 



Fig. 14. 

 Dryocoetes autographus. Work in larch bark; 

 larvae one-third grown. 



[89] 



