Flowering and Fruiting - The fragrant, whitish flowers, borne in showy racemes, appear after leaf emergence in May or June. The perfect flowers originate in the axils of current year leaves and are pollinated by insects, primarily bees. The fruit is a flattened, oblong pod that ripens during September and October. The fruit opens on the tree and seeds are dispersed from September to April.

Damaging Agents- Black locust is severely damaged by insects and disease, probably more than any other eastern hardwood species. Ubiquitous attacks by the locust borer (Megacyllene robiniae) and by the heart rot fungi Phellinus rimosus or Polyporus robiniophilus make growing black locust for timber production impractical. Locust borer larvae construct feeding tunnels throughout the wood, and the holes serve as entry points for heart rot fungi that cause extensive wood decay. Locust borer attacks can begin at a young age and damage can be so extensive that trees are not suitable for fence posts. Many plantations planted in reclamation projects were seriously damaged, but more trees could be used if cut as soon as they reach post or mine-prop size. Slow-growing trees on poor sites are most susceptible to borer attack. On sites where tree vigor is low, repeated attacks often reduce black locust to sprout clumps. Damage to the sprouts is often as severe as in the original stem.

Locust Borer Beetle, Megacyllene robiniae