The wood of black locust, Robinia pseudoacacia, is used chiefly for insulator pins, wagon hubs, treenails, fence posts, and mine timbers. For these uses it is admirable because of its hardness, strength, and durability. A valuable characteristic of the tree is its rapid growth on many types of soils during the first 20 to 30 years of its life. This rapid growth and the extensive network of roots developed by black locust make it well suited for planting to check erosion. The greatest obstacle to more extensive cultivation and utilization of black locust is the locust borer, Oyllene robiicae, a black or brown and yellow-striped, long-horned beetle that attacks small trees and riddles the wood. The numerous holes that it makes may render the wood valueless and often so weaken the trees that they are easily broken by the wind. The damage from the borer has not been nearly so serious in the West as in the East. Under some conditions, plantations of black locust may be at least Partly protected from the borer if the locusts are planted in thick stands or so mixed with other trees as to produce dense shade. So grown they are more apt to be free from locust attacks and will early drop off their lower branches and develop clean, straight poles during the first 10 to 15 years of growth
