These beetles typically feed on the inner bark of the lower four feet of the trunk and may even girdle the tree. Characteristic signs of turpentine beetle injury include long clumps of hardened sap around the lower trunk and reddish sawdust around the very small entry holes. In addition, the introduction of the bluestain fungi can destroy cambial tissue and compound the injury caused by the beetles. A pine affected by this pest complex will show a yellowing or rusty browning throughout the entire tree before the foliage begins to die and needles begin to drop, often within the year. The nematodes enter through feeding wounds, reproduce quite rapidly, feed on the tree from the inside out, and cause localized foliage dieback before the tree quickly begins to yellow, wilt and die.
Trees can often die within months of initial nematode infestation.
Japanese black pines are most susceptible to either of these pest complexes if they are older than 15 years of age or are growing in stressful sites, such as near the coast. The greatest attraction to Japanese black pine in the northeast is its salt tolerance. Yet it seems to be more susceptible to disease in salty environments. Current research at URI has identified two possible alternatives for salt-tolerant windscreens in coastal plantings. Foliage will appear a bit denser than on Japanese black pine.