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Show without materially deforming the ' tree it would he well to cut out and ; burn them. It is very inadvisable to plant poplar and cotton wood trees; those already growing should be replaced as rapidly as possible with the : more desirable varieties of shade trees which do not serve as favor- , able hosts for various tree diseases and insect pests. j selected portion of the tree. After feeding has begun, the insects in-sects then begin to secrete over themselves a new waxy protective covering. Feeding continues until fall when eggs are laid again and the old insects die. The most effective method of killing kill-ing the oyster-shell scale is to spray the infested trees with a good miscible oil. This is applied in the spring before the trees leaf out. Miscible oil is a specially prepared spray oil which mixes readily with water and when applied on oyster-shell oyster-shell scale, it penetrates the waxy coverings and destroys the eggs. When it is observed that the scale infestation is limited to one or two limbs which may be pruned out the gradual death of the infested portations. The infestation in question ques-tion is particularly common ou the blue ash trees. The cause of the condition described de-scribed is the oyster-shell scale. The oyster-shell scale is an insect about the size of a pin-head. This insect secretes a waxy covering over its body which is about one-eighth of an inch long and its shape resembles resem-bles a tiny oyster-shell hence its name. The color of this scale-like covering of tlie insect is similar to that of the bark of the tree upon which the scale is found. The covering cov-ering protects the insect from the weather and from its natural enemies. ene-mies. if, during the winter time, the female scale coverings which have been formed during the preceeding i summer, are turned over there will be found from o(J to lou tiny pearly white eggs. These hatch in the spring ; the time depending much on weather conditions. The pale yellowish-white young insects are mere specks when first hatched and are very active. They crawl out from under the old scale covering and seek a new clear place on the bark where they can settle down never to move again during their entire life. In the new place selected, the insects in-sects insert their long threadlike beaks into the bark and begin sucking suck-ing the sap of the tree which constitutes con-stitutes on ever ready supply of food so long as the infestation does not become so heavy as to kill the J SHADETREESl jwhat's the Matter Withjj Them, and What to Do. j By CHARLES J. SOKENSON. District Agricultural Inspector.. A number of people have inquired concerning the cause of the un-healthful un-healthful appearance of certain varieties var-ieties of shade trees growing along the streets and in city parks. A bit of close observation shows that a majority of the poplar, cotton-wood cotton-wood and ash trees have portions of their limbs densely covered with a dark scurfy growth which causes |