Relation of Nantucket Pine Tip Moth Attack and Fusiform Rust Infection in Loblolly Pine Families

Abstract The relationship between pine tip moth attack and fusiform rust infection was studied in a 12-year-old loblolly pine stand in Houston County, GA. Four pine families were selected for study, and 24 trees of each family were felled for evaluation. The lower 8 ft of each tree was cut into two 4-ft sections and split to reveal the pith. Each section was examined for evidence of pine tip moth attack and the presence of fusiform rust galls. The analysis revealed 476 tip moth attacks and 99 fusiform rust galls. Forty-six of the rust galls occurred at the same place as a tip moth attack. These results, when combined with those of previous studies, suggest that the control of the pine tip moth may reduce the incidence of fusiform rust. Growth and yield simulations and economic analyses indicate that insecticide treatment of loblolly pine for the combined control of the pine tip moth and the associated reduction in levels of fusiform rust infection may be potentially cost effective in stands managed for sawtimber, but not for pulpwood. South. J. Appl. For. 15(4):204-208.