SHORTLEAF PINE I IMPORTANCE AND MANAGEMENT. 27 



fields or under full light exposure. Following the unusually wet 

 spring and early summer of 1912, the infestation was general in the 

 Piedmont region and southern Mississippi Valley. In an extreme 

 case of a 9-year-old stand, as high as 90 per cent of the shortleaf sap- 

 lings showed injury. 1 Some had been attacked by at least two genera- 

 tions of insects during midsummer, and, as a result, developed two 

 sets of adventitious leaders. 



Larvae of the southern pine sawyer, or round-headed borer, Mono- 

 hammus titillator Fab., 2 develop from eggs laid under the bark of 

 felled or dead trees by the adult beetle. The insect never attacks 

 living trees in the South. If allowed to dry rapidly by removing 

 the bark, or if immersed in water, the wood is little subject to injury 

 by the insect. 



FUNGI. 



The most practical means of combating the injury and loss of tim- 

 ber by fungi is to prevent, so far as possible, the occurrence of wounds 

 in the tree through which the fungus finds its direct avenue of at- 

 tack. The most serious cause of the formation of wounds is fire. 

 Infested trees should be selected for cutting, since they are the 

 breeding places for spores or "seed," which are minute in size and 

 produced in vast numbers. 



YIELD. 



The productiveness of the tree, especially of second growth or 

 young timber, being the basis of management, a knowledge of the 

 yield, or amount of wood produced per acre, is essential in order to 

 decide the time and method of cutting, the probability of success, 

 and other important points in handling the forest crop. Yield 

 tables are particularly valuable for trees like shortleaf pine, which 

 come in extensively in even-aged second-growth stands following the 

 removal of the virgin forest and the abandonment of fields cleared 

 for agriculture. For such stands normal yield tables give the in- 

 formation most needed. These are obtained from measurements 

 taken in fully stocked pure stands, or portions of stands, and show 

 the possibilities of the species at various ages. Yield tables thus 

 made are used as guides in ascertaining the present total volume of 

 the growing stock and period of highest productivity in the life of 

 the stand, and in predicting future yields of the forest at given ages. 

 Many stands or portions of stands, however, are not more than two- 

 tliinls to three-quarters fully stocked, because of insufficient seed, 

 direct injury from fires, and losses by insects or fungi. A deduction 



'Mixed stand in which <;lo shortleaf and 380 loblolly had been Infested and 70 short- 

 leaf and 10 ioMolly showed do Injury. (Mi. Wrnon, Glenvllle 1*. O., Arkansas.) 

 Bureau of Kntomolo^y nulletlu 58, "Some insects Injurious to Forests." 



