BORING INSECTS 67 



trunks and lower limbs of the trees should be 

 painted with the mixture at intervals of two or 

 three weeks during the danger season. 



Similar in results, but unlike in the way they 

 are attained, are whitewash and cement paint. 

 Whitewash must be applied heavily and very 

 thoroughly, the loose bark being previously 

 brushed off. It must be renewed as often as the 

 weather destroys its completeness of covering. 

 Cement paint, made by mixing, to the consistency 

 of heavy paint, Portland cement in skimmed milk, 

 makes an extremely effective protection and lasts 

 the whole season. It, as also whitewash, can be 

 colored to suit the operator's fancy. 



These campaigns must of course be planned in 

 advance. Above all, the egg-laying season of the 

 particular insect in hand must be determined. If 

 doubt as to that point exists, consult the entomolo- 

 gist of your State Experiment Station, sending 

 him a full description of the injury, and, if possi- 

 ble, specimens of the insect. 



Preventive measures such as these, however, are 

 not exactly tree repairing. 



The only way to fight the borers after they have 

 attacked a tree is to dig them out or kill them indi- 

 vidually in their burrows. The work can be done 

 at any time, but perhaps late summer and early fall 

 are the best. The operator should provide him- 

 self with the tools ordinarily used in treating bark 



