Adult pine seedworm.
The female moth lays eggs from April through May on second-year cones. There is one generation per year. Larvae feed within developing seeds until the cone matures. In late fall, larvae either bore into the cone axis or remain in a hollowed-out seed, and overwinter. Pupation occurs within the cone and moths emerge through the hollow seeds. External evidence of seedworm attack is not visible in immature cones. As cones mature, damaged seeds are retained in the cone. Heavily damaged cones do not open properly. In high-value seed orchards and seed production areas some protection from seedworm attack may be obtained through the use of pesticides applied in a carefully timed program.
Pine seedworm larva in longleaf pine seed.
BALSAM WOOLLY APHID, Adelges piceae (Ratzeburg)
Eggs and wool-covered adult balsam woolly aphids.
The balsam woolly aphid was introduced into northeastern North America from Europe around the turn of the century. Since then it has become a pest of major importance to true firs on the east and west coasts of the continent, and threatens some 60,000 acres of Fraser fir in the southern Appalachians. Usually the balsam woolly aphid has two generations per year in the southern Appalachians. Eggs of the first generation hatch in late June and July followed by the second generation in September and October. The immature stage of the aphid known as a “crawler” is the only motile stage in the aphid’s life cycle. Once the crawler begins feeding, it transforms into an adult and never again moves. Reproduction is parthenogenic with each female laying approximately 100 eggs during her lifetime.
In the feeding process the aphid injects a salivary substance into the host tree, which causes growth abnormalities. Initial symptoms of aphid attack may include “gouting” of buds or twig nodes and some twig and branch die-back. Heavy stem attacks reduce the tree’s ability to translocate food and water. Usually a heavily infested tree dies within two to seven years.