22 



INJURY BY GALL INSECTS. ORDER HYMENOPTERA. 

 F^^irr OF G^^k^SE 15. 



54. Bird's-eye Pine {('hulcididf) . 



A common condition of the wood of the western yellow pine evidently caused by 

 a minute four-winged gnat, fragments of which were found in jjitch galls in the bark 

 of the main stem of young living pine. The formation of corky wood cells around 

 the accumulation of pitch in the wound produces in the subsequent layers of wood 

 the wavy and so-called birds-eye effect in the wood of larger trees. Insects found in 

 specimen at Albany, Oreg. Specimen of wood from Grants Pass, Oreg. 



Exhibit: Work. 



55. The Oak-Twig Ormyrus {Ormyrus sp.). 



A minute four-winged gnat breeding in small gall-like cavities in the living bark 

 on the branches and twigs of the Oregon white oak in western Oregon, causing the 

 small and large oak trees to present a dying appearance, due to the great number of 

 dying twigs and dead leaves. The healed-over wounds produce deformed branches 

 and defective wood. 



Exhibit: Wokk. 



INJURY BY BARK AND WOOD-BORING GRUBS. ORDER COLEOP- 

 TERA, FAMILY BUPRESTID^. 



CASE IG, 



56. The Western Hemlock Bark-Borer {Melanoph'da drummondi Kirby). 



A medium-sized, flat-headed, bark-boring grub, excavating shallow, winding bur- 

 rows through the inner layers of bark of living, injured, and recently felled western 

 hemlock and Douglas spruce; California to northern and eastern Washington and 

 western Idaho, and in the noble fir near Detroit, Oreg. A very common and 

 destructive enemy, killing the largest and best trees, or causing serious "gum spot" 

 defects in the wood of living ones. 



Exhibit: Adult and work. 



INJURY BY BARK-WEEVILS. ORDER COLEOPTERA, FAMILY 



CURCULIONID-ffi. 



FART OW CA.SE 17. 



57. The Sugar Pine Bark- Weevil {Pissodes sp. ). 



Adult snout-beetle deposits eggs in the outer bark of young living and injured 

 sugar pine, producing small whitish grubs which mine through the inner bark and 

 change to the adult in oval cavities excavated in the surface of the wood, causing the 

 death or abnormal development of the trees. Grants Pass, Oreg. 



Exhibit: Work. 



58. The Doug'las Spruce Twig- Weevil {CurcuUonid). 



A small snout-beetle which deposits eggs in cavities in the bark of the small cen- 

 tral shoots and terminal twigs of young, living Douglas spruce. The small whitish 

 grubs mine through the inner bark and enter the pith to change to the adult, killing 

 the twigs and causing a deformed development of the tree. St. Helen, Oreg. 



Exhibit: Work. 



59. The Pine Fungus-Gall Weevil {CurcuUonid). 



A small snout-beetle breeding in the bark and wood of a common fungus gall on 

 the shore pine and western yellow pine, causing the death of the branches and young 

 trees. Newport, Oreg., and Moscow Mountains, Idaho. 



PIxhibit: Work. 



