87 

 INSECTS INJURIOUS TO THE PLUM. 



The Roots- 



(a) Burrowing about the crown of the roots, occasionally in young trees — 

 Peach-Tree Borer (Sannina exitiosa). 



The Trunk, Branches and Twigs— 



(a) Making tunnels in the wood, sawdust-like excrement at the mouth of 

 tunnels — Flat-Headed Borer (Chrysobothris femorata). 



(b) Making tunnels in the bark — Fruit Bark-Beetle (Scolytus rugulosus). 



(c) Bases of buds perforated, the bark becomes discolored, and the leaves 

 and fruit wither — Pear-Blight Beetle (Xyleborus pyri). 



(d) Fixed to Bark — 



(1) Flat or saddle-shaped, or hemispherical dark brown scales. Large 

 scales after mid-summer are brittle and contain only a whitish dust or empty 

 egg-shells. Wintering forms are small and flattish — Plum Lecanium 

 (Lecanium cerasifex). 



(2) Ashy gray appearance of bark of badly infested trees; small gray 

 or black circular scales — San Jose Scale (Aspidiotus perniciosus). 



(3) Mussel-shaped scales, with whitish eggs underneath in winter — 

 Oyster-Shell Scale (Lepidosaphes ulmi), 



(4) Bark scurfy with scales, purplish eggs underneath in winter — Scurfy 

 Scale (Chionaspis furfurus)v 



(e) Producing longitudinal slits and eventually oval-shaped scars — Buffalo 

 Tree-Hopper (Ceresa bubalus). 



The Leaves — 



(a) Feeding in Colonies. 



(1) Protected by webs in the forks of branches— American Tent-Cater- 

 pillar (Clisiocampa Americana). 



