Life Tables of the White Pine Weevil, Pissodes strobi , 1 in Central Maine 2

Life tables (1977–1980) are presented for three generations of the white pine weevil, Pissodes strobi (Peck) (Coleoptera: Curculionidae), a pest insect of eastern white pine, Pinus strobus L. Typically, female weevils oviposited ca. 140 eggs per terminal leader of a host tree in the spring; however, only 1 progeny adult survived to the following spring. Average generation survival (SG = 0.008) and total generation mortality (K = 2.08) reflected observed small increases in weevil infestation each year. Key factor analysis suggested that larval, pupal, and winter submortalities were the major influences on population change. Submortality factors were: (1) egg infertility, (2) pitch-drowning, (3) larval instraspecific competition, (4) natural enemy predation and parasitism, (5) nonemergent brood adults, (6) unknown cause(s) of death, and (7) effect of climatic conditions on overwintering adults.