The most serious damage occurred in the Town Creek plantations, which are 

 2 to 7 years old and located on the Boise National Forest near Centerville, 

 Idaho. This damage was caused by the June feeding of a tussock moth, which 

 most commonly stripped all but the current year's needles. The feeding 

 occurred in small areas and in an irregular pattern over some 500 acres. The 

 many stems of Ceanothus, which form the main ground cover, were completely 

 stripped in affected areas. So far, no mortality of the planted trees has 

 occurred, but the larvae from the many egg masses on the leaders could feed on 

 the remaining foliage and weaken the trees still further. This instance of 

 feeding on ponderosa pine by the tussock moth may result in understocking from 

 mortality before the outbreak subsides. 



The fact that the plantations have suffered these attacks is interesting, 

 but more important are the implications to be considered when new plantations 

 are planned. The choice of species for regeneration should be considered 

 most carefully. The area of plantations in the West is increasing annually 

 and will increase at a faster rate in the near future. To forestall, or at 

 least minimize, the effects of destructive agents, the silviculturist should 

 observe certain known and important principles. 



First, he should use stock raised from seed collected as near the planting 

 site as possible and from acceptable individuals. He may wish to consider 

 planting more than one of the native species so that one or more could serve 

 as buffers. Second, he should critically appraise the most suitable preventive 

 measures against pests and, if possible, apply the most appropriate ones. 

 Poisons or repellents against animals are obviously a wise precaution. 

 Nursery stock reinforced by systemic additives are certain possibilities and 

 will become increasingly important. Third, he must remember that the form 

 and development of stands can be markedly influenced by the physical arrangement 

 or patterns of planted trees such as alternate rows, groups, and various 

 spacings . 



In any event, the establishment of plantations should not be regarded as 

 an easy alternative to natural regeneration that requires only money and 

 manpower to implement. Successful plantations should not be due to chance but 

 to the acumen and skill of the silviculturist. 



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