INSECTS AFFECTING PARK AND WOODLAND TREES 221 



Li ri od en d ro n t u 1 i p i f e r a Linn. S c i a d o p i t y s verticil lata Sieb. & 



Tuliptree. Zucc. Umbrella pine. 



Lycium h a 1 i ni i f o 1 i u m Mill. Matri- Shepherdia sp. 



mony vine. S ni i 1 a x sp. 



Ma gn o 1 ia (all species). S o j) h o r a j a jj o n i c a Linn. Japanese 



Myrica cerifera Linn. Wax myrtle. pagoda tree. 



Nyssa sylvatica Marsh. Tujjelo, S t a p h y 1 e a sp. Bladder nut. 



Pepperidge, Black gum. Sour gum. Stephanandra flexuosa .Sieb. & 



Ostrya virgin ica Wild. Hornbeam, Zucc. 



Ironwood. Sty rax japonica Siel). & Zucc. 



P a u 1 o w n i a i m p e r i a 1 i s Sieb. & Zucc. T a m a r i x sp. 



Ph el 1 oden d ron sp. T a x o d i u m distichum Rich. Bald 



Philadelphus coronarius Linn. cyjiress. 



Mock orange, syringa. Tax us sp. Yew. 



Pin us sp. Pine. Tecoma radicans Juss. Trumpet 



Plat an us occidentalis Linn. Amer- creeper. 



ican plane. Buttonwood. Tsuga canadensis Carr. Common 



Potentilla fruticosa Linn. hemlock. 



Que re us (all species). Oak. V a c c i n i u ni sp. 



Retinispora (all species). Japan Wistaria sp. 



cy])ress. " Xanthocerassorliifolia Bunge. 



Rhamnus sp. Buckthorn. Xanthoxylum am eric an urn Mill. 



Rhododendron sp. Prickly ash. 



The above list shows a very wide range of food plants, and it will 

 undoubtedly prove of considerable value to parties setting out trees in 

 sections where this pest occurs, since it may be possible in many instances, 

 to select species not liable to serious injury, a procedure which might 

 result in material saving in the course of a few years. It is also well to 

 call attention in this connection to the limited means of dispersal possessed 

 by this species, and on large estates in particular, it would probably be 

 advantageous to have the surrounding trees, so far as possible without 

 interfering with more important plans, largely of species unfavorable 

 to the development of the scale. This would materially lessen the danger 

 of its being brought on the place, and the likelihood that control work 

 would be marred by the indifference of adjacent landowners would be 

 much diminished. 



Means of dissemination. The method of spread is of considerable 

 importance, particularly in places where this scale has not become estab- 

 lished. It is conveyed long distances almost entirely by nursery stock and 

 there is very great danger in budding from infested stock, since this scale 

 insect has a marked tendency to gather about buds and other rough portions 



