28 AGRICULTURAL AND MECHANICAL COLLEGE OF TEXAS. 



eating insects, but for sucking insects one must use soap or oil solutions 

 which will clog the breathing pores. 



Wood borers work beneath the surface and cannot be reached by 

 spraying, but must be removed from the bark by digging them out or 

 killed by filling the galleries with carbon bisulphid and then plugging 

 up the entrances. Whitewashing the trees for protection against boring 

 insects is common practice throughout the State. There has been very 

 little investigation to determine whether this treatment is effective or 

 not. When applied to young, thin-barked trees or to the smaller 

 branches of any tree there is danger that whitewash will clog the 

 breathing pores of the bark and cause a distinct injury. The city of 

 Chicago recognizes this possible injurious effect and has prohibited, by 

 ordinance, the whitewashing of city trees: As a further means of keep- 

 ing these breathing pores open it is advisable to wash down the leaves, 

 branches and trunk of a tree at frequent intervals in order to remove 

 clogging particles of dust, The whitewashing of -large trunks and 

 thick-barked trees can do no possible injury and may be effective against 

 borers. 



The State Entomologist, at College Station, will gladly furnish in- 

 formation and answer inquiries concerning insect control upon request. 



PROFIT FROM PLANTING. 



Although direct financial returns through the sale of wood products 

 cannot be derived from trees planted for shade or ornamental purposes 

 there yet exists a definite value in many forms. Building sites are 

 influenced by the presence or absence of appropriate tree growth. Trees 

 planted for shade and landscape effects unquestionably increase real 

 estate values. 



In addition to such tangible results the sentimental or aesthetic value 

 of the trees must be considered. One can scarcely estimate the value of 

 a tree which has furnished shade and stood as an object of beauty for 

 many years. Yet a value is recognized and fine old trees are often saved 

 by building around them when improvements are made. Xor can one 

 fix a value on the effect of tree growth in the health and everyday living 

 conditions of a community. Statistics show that mortality figures rise 

 during the hot months of the year and that trees, by giving off oxygen 

 and moisture from the leaves, lower the temperature, purify the atmos- 

 phere and promote the general welfare of the community. Where the 

 public highways of the State and the streets of cities and towns are 

 planted with trees it is impossible to estimate in dollars and cents the 

 prestige and recognition accruing to the commonwealth fortunate enough 

 to possess them. 



Various standards of appraisal have been devised to apply to shade 

 trees. The "Parker Standard," probably the best of them, gives a 

 rating of 100 per cent to a tree which is perfect in position, species, 

 trunk condition, top condition, general desirability and scenic value. 

 Seductions on a percentage basis are made for defects under these head- 

 ings and the resultant figures totaled. This percentage rating of the 



