HABITS AND GROWTH. 



Black locust grows best on a deep, well-drained, fertile loam, but 

 will grow on almost any soil except a wet, heavy one. It attains an 

 excellent development on limestone formations. 



The tree is very intolerant and requires an abundance of light dur- 

 ing its entire life. When overshadowed it declines quickly. 



In its native home black locust is found along streams, on the bor- 

 ders of the forest, or singly and in groups on the steep slopes. On 

 slopes its principal associates are black, red, and chestnut oaks, 

 chestnut, pignut hickory, and maple. Along streams it grows with 

 ash, maple, black walnut, and other trees. On forest land that has 

 been burned over it often grows in pure stands. 



Black locust is rapid growing, but relatively short lived. In 

 good situations it may make an average annual height growth of 

 2 to 4 feet and a diameter growth of one-quarter to one-half inch. 

 This rate is sometimes maintained for twenty-five or thirty years, 

 but more frequently the rate of growth lessens between the ages of 

 15 and 20 years. After fifty years growth almost entirely ceases. 



THE LOCUST BORER. 



The value of black locust is practically destroyed in many parts of 

 the United States by the locust borer, a black or brown and yellow 

 striped, long-horned beetle. The grubs or larvse of this insect bur- 

 row in the inner bark and sapwood, and if present in sufficient 

 number either kill the tree or cause it to become stunted and worth- 

 less. The value of the wood is decreased or destroyed by the many 

 worm holes that result from a severe attack. If a plantation is 

 severely infested when the trees are very small, it is killed outright 

 within a short time. Where attacks are not severe, it is sometimes 

 possible to grow trees to fence-post size before the plantation is seri- 

 ously affected. Plantations of locust in Oklahoma and in the States 

 west of the Rocky Mountains are almost entirely free from this 

 injury. In most of the States east of the Rocky Mountains planting 

 is restricted or made impossible by the presence of the borer. In case 

 this insect or others seriously injure a forest plantation the Bureau 

 of Entomology of the Department of Agriculture should be con- 

 sulted at once. 



ECONOMIC USES. 



The timber of the locust is extensively used for fence posts, ties, 

 ribs of vessels, treenails, insulator pins, and vehicle stock. Its great 

 durability in contact with the soil makes it very valuable for use in 

 the ground, and its toughness and elasticity give it value where 



[Cm. 64] 



