Nantucket pine tip moth, Rhyacionia frustrana (Comstock) (2, 48, 51)

BIOLOGY. - Moths emerge from overwintering pupae and lay their eggs on conelets or shoots in the early spring. There are two to five generations per year, depending on latitude. Larvae injure shoots and buds, but those of the first generation cause significant conelet mortality by feeding directly in and on the flowers and conelets. Minor conelet attack may also occur during the last generation in the fall.

INSECT IDENTIFICATION. - Larval coloration varies with age. Young larvae are cream colored, while mature larvae range from light-brown to orange. Head capsule and thoracic shield are black. In contrast to young coneworm larvae, tip moth larvae have no dark spots on setal bases.

Moth with forewing marked with irregular brick-red and coffee-colored patches separated by a background of gray scales.

Adult. (5X)

DAMAGE IDENTIFICATION. - A newly hatched Nantucket pine tip moth larva often bores into and destroys one or two conelets. Minute frass on the conelet surface is the first sign of larval boring. Later, a small quantity of resin often accumulates around or over the lesion. When older, the larva migrates to the supporting shoot or another conelet, laying down a loose network of webbing between the shoot and the adjacent injured conelet. A larva may also enter another shoot, killing it and any conelets it bears.

Shortleaf pine conelets killed by larvae. (1X)

IMPORTANCE. - Tip moths severely damage shoots in young pine plantations up to 3 meters tall (primarily loblolly, shortleaf, and Virginia pines) and often reduce the survival of outplanted grafted stock during seed orchard establishment. In older orchards, tip moths infest shoots during the summer and fall, destroying buds containing embryonic flower primordia and thereby reducing flower production the following year. Direct attacks on shortleaf pine conelets often cause losses of 30 percent or more.