The PSHB penetrates host trees through the bark, into the sapwood. Entrance holes can be seen having brown stains around the perimeter due to the associated fungus. Other signs of entry include the presence of small heaps of sawdust, “bleeding”, noodles, stains or sap-flow. Infected trees normally show wilted and brown leaves, with branch dieback being a clear indicator of damaged vascular systems. This causes more stress in the tree, making it more susceptible to secondary infestations, ultimately leading to death. Branch dieback causes weakening in the structural integrity of affected trees, causing dead branches to fall unpredictably. This can lead to property damage and possibly injury or death.