THE LOCUSTS 



91 



trunk and branches before the time the mature beetles 

 lay their eggs in August. The beetles feed on golden rod, 

 and may be collected and destroyed. The expense of 

 special treatment to control the borers is prohibitive in 

 the case of plantations. Therefore, unless careful obser- 

 vation indicates that the black locust will not be seriously 



GROWTH FROM SEED PLANTING 



Black Locust Grove in Southern Indiana, only nine years old, from seed. Poor 

 soil in an old pasture was ploughed up and seeded to locust nine years before 

 this photograph was taken. Cultivation was given the first year, after which 

 it was neglected and the cattle permitted to enter the plantation. The grove 

 was thinned twice. An estimate of the timber, as shown in the photograph, 

 established the fact that there were 394 trees per acre, estimated to yield 1.028 

 fence posts, worth 20 cents each on the ground — a value of more than $20 per 

 acre per year. 



injured by its most destructive pest, it should not be set 

 out in plantations. In certain localities the borers have 

 not yet become numerous enough to harm the locust trees 

 to any great extent; this is true especially of Oklahoma 

 and the states west of the Rocky Mountains. 



Another insect, a leaf miner, has caused much damage 

 to locusts in portions of the eastern United .States. This 

 insect causes the leaves to turn brown, as though scorched 

 by fire. Young trees seem to suffer most, and are weak- 

 ened so that they easily die from other causes. The remedy 

 is an arsenical spray, but this is practical only in the case 

 of shade trees. A fungus known as the yellow-rot is very 

 destructive to the heartwood of living trees, and is the 

 cause of the hollow trunks of so many old black locusts. 

 Another heart-rot, the sulphur polypore, is a very de- 

 structive disease that sometimes attacks this tree. The 

 fruiting bodies of these fungi are shelf-Hke growths that 

 push their way through the bark. 



The wood of black locust is very hard, stiff, strong 

 and durable. Its extreme hardness is due to minute crys- 

 tals, which soon dull the edges of cutting tools. It is coarse 

 grained and splits readily. The heart wood is yellowish 

 brown and for this reason the tree is frequently called 

 yeUow locust. Sometimes the wood has a dark reddish 

 brown or greenish tinge. The sapwood is yello\vish white, 

 and forms a very narrow band around the heart wood; it 

 does not resist decay like the latter. The principal uses of 

 the wood are for fence posts and rails, insulator pins for 

 telephone and telegraph cross arms, tree nails and the 

 hubs of carriage wheels. Under average conditions, locust 

 posts will last 20 to 35 years, and accordingly, they have 



a high market value. The wood makes excellent fuel, and 

 is also valuable for railroad tics and the ribs of vessels. 

 It does not enter largely into manufactured lumber be- 

 cause the supply is limited, and is u.sed for the special 

 purposes to which it is best adapted. The bark of the 

 roots is poisonous when eaten in large quantities, but in 

 small doses it is used as a tonic in homeopathic medicines. 

 Black locust leaves furnish a principle similar to that 

 from which indigo is obtained, but it is not known to be 

 of commercial use. 



A spineless variety of black locust has a darker colored 

 foliage than the common form. Tlic clammy locust 



WITH OR WITHOUT THORNS 



Honey locust branches low and forms a spreading, rounded top when growing in 

 the open. The lower branches extend at nearly right angles to the trunk, and 

 the beauty of the tree is emphasized by the light and graceful foliage. The 

 trunk and older branches usually have strong thorns, but a variety free from 

 thorns is available for planting where thorns are objectionable. 



{Robinia viscosa) is a small tree or shrub of the North 

 Carolina mountains. It is so named because the twigs 

 and leaf stems are coated with a sticky substance. Its 

 flowers are pale rose color, larger and blooming later than 

 those of black locust. The bristly locust or rose acacia 

 {Robinia hispida) is another shrub or small tree that grows 

 wild in the Southern Allegheny mountains. It is very 

 prickly, and has large and very beautiful rose-colored 

 blossoms that appear in June or July. It is much planted 

 for ornament, and does well on sandy soils and near the 

 sea shore, but may become objectionable because of its 

 abundant root suckers. The New Mexican locust [Robinia 

 neo-mexicana) is found in the semi-arid portions of 

 southern Utah, Colorado, Arizona and New Mexico. It 

 is more of a shrub than a tree, but produces handsome 



