Red-pine conelet, cone and seed losses to insects and other factors in an open-grown plantation and a seed orchard

The temporal sequence and causes of seed and cone loss was investigated at a Pinus resinosa seed orchard and a widely-spaced planting of the same tree species. Damage was converted to seed loss for each of several designated intervals after flower emergence: 0–4 months, 4–11 months, 11–15 months, and within surviving cones ( sc). The 0–4-month interval was the major period of loss in the seed orchard, and conelet abortion the major mortality factor. Cone-destroying insects, interval 11–15, were very damaging in 1985, when the cone crop was relatively small, but relatively unimportant in 1986. Empty seed in sc accounted for the second greatest overall seed loss. Seed-bugs were implicated in some seed damage using X-ray analysis. In the plantation the major seed loss occurred in sc. The major damaging agent was Cydia toreuta. Strobili and conelet mortalities were much lower at the plantation site than at the seed-orchard site. Cone survival was high in all three years studied.