LLUSTRATIONS. 



PIATES. 



Page. 



Plate I. Classification of the genus Dendroctonus, showing technical and com- 

 mon names and species numbers 1 



II. Map of the world, showing distribution of the genus Dendroctonus. . 14 



TEXT FIGURES. 



Fig. 1. The red turpentine beetle {Dendroctonus valens): Adult, dorsal aspect. 6 



2. The red turpentine beetle: Adult, ventral aspect 8 



3. The red turpentine beetle: Adult, lateral aspect 9 



4. The red turpentine beetle: Larva, ventral, lateral, and dorsal aspects. 11 



5. The red turpentine beetle: Pupa, dorsal, lateral, and ventral aspects. . 13 



6. The western pine beetle (Dendroctonus brevwomis): Adult, larva, pupa. 42 



7. The western pine beetle: Egg galleries 43 



8. The western pine beetle: Bark showing pupal cells, exit burrows, and 



pitch tubes 44 



9. Work of the western pine beetle: Pitch tubes on bark of tree 45 



10. Western yellow pine killed by the western pine beetle 47 



11. The western pine beetle: Distribution map 48 



12. The southwestern pine beetle (Dendroctonus barheri): Adult 49 



13. The southwestern pine beetle: Egg galleries 50 



14. The southwestern pine beetle: Distribution map 52 



15. The roimdheaded pine beetle (Dendroctonus convenfrons) : Adult 53 



16. The roundheaded pine beetle: Egg galleries and larval mines 54 



17. The roundheaded pine beetle: Distribution map 56 



18. The southern pine beetle (Dendroctonus frontalis): Adult 57 



19. The southern pine beetle: E^ galleries and larval mines 58 



20. The southern pine beetle: Termination of egg galleries 61 



21. The southern pine beetle: Beginning of egg galleries 61 



22. The southern pine beetle: Bark showing pitch tubes, etc 61 



23. The southern pine beetle: Old egg galleries in living tree 62 



24. The southern pine beetle: Egg gallery in living tree, the resulting 



wound in process of healing 62 



25. ^Tiite pine timber killed by the southern pine beetle 63 



26. Table Mountain pine. Mineral County, W. Va., seven years after it 



was killed by the southern pine beetle 64 



27. A forest of Table Mountain pine. Mineral County, W. Va., seven years 



after it was killed by the southern pine beetle 65 



28. Spruce timber killed by the southern pine beetle, mountains of Tran- 



sylvania County, N. C - - - - - *>6 



29. The southern pine beetle: Section of pine trunk, bark removed, showing 



marks of galleries and bluing on surface of wood - 67 



30. The southern pine beetle: Egg galleries and larval mines, and larval 



mines of round-headed bark-borer 68 



31. The southern pine beetle: Distribution map 70 



XIII 



