Susceptibility of parent and interspecific F1 hybrid pine trees to tip moth damage in a coastal North Carolina planting

Tip moth damage among families of parent pine species and their interspecif ic F1 hybrids was quantitatively assessed in a coastal planting in North Ca rolina. Three slash pine (Pinus elliotti var. elliotti Engelm.), two loblol ly pine (Pinus taeda L.), and four interspecific F1 hybrid pine families we re used. The F1 hybrids were as susceptible to damage by Nantucket pine tip moth (Rhyacionia frustrana (Comst.)), as was their susceptible loblolly pi ne parent. Their phenotypes support a dominant or partially dominant mode o f inheritance for susceptibility. The phenotype of one slash pine family wa s not statistically different from the phenotypes of the loblolly and F1 hy brid pines. The high susceptibility of that one slash pine family appeared to be intrinsic, even though slash pine is considered resistant to tip moth damage. Tip moth damage on the two other slash pine families was significa ntly lower.