Life tables were constructed for six generations ofRhyacionia frustrana(Comstock) and for one generation ofRhyacionia rigidana(Fernald) in a 2- to 3-year-old loblolly pine plantation. Overlapping stage-density trend curves were estimated for each generation by a schedule of two-stage cluster samples. Population models were applied to these curves to estimate stage recruitments for the life tables. Important mortality occurred during egg and pupal stages. Egg mortality was high, and perhaps density dependent.Triehogrammasp. caused much egg mortality in generations 2 and 3, but an unknown factor caused most generation 1 egg mortality. Fifth-instar larvae were heavily parasitized byLixophaga mediocrisAldrich, but this mortality was constant and was not a key factor. Some pupal mortality was caused by parasites. However, sources of most pupal mortalily were not identified. The pattern of survivorship forR. rigidanawas similar except for high 1st-instar mortality, apparently due to resin from feeding wounds on pine Shoots. Sex ratios and fecundities were also examined.