Common Name: Nantucket pine tip moth
Scientific Name: Rhyacionia frustrana (Comstock)
Description: The adult moth is slightly less than 1/4 inch long with reddish-brown to copper and silver-gray marked wings, which are held over the back of the body when at rest. The larva (caterpillar) grows to about 3/8 inch long with a black head, and as it develops the body color changes from cream to orangish-brown.
There may be a complex of tip moth species, particularly in west Texas. In addition, occasionally caterpillars of the southern pine coneworm, Dioryctria amatella (Hulst) (Lepidoptera: Pyralidae) also tunnel into shoots of southern pines. However, caterpillars are much larger and creamy white to dark gray-brown in body color, rather than orangish.
Life Cycle: Winter is spent in the pupal stage within infested host plants. Adult moths emerge in early spring (February-March), mate and females lay whitish to orangish eggs on needles on developing tips or buds. Cream-colored, 1/16 inch long larvae hatch from eggs within 5 to 31 days depending on temperature, and begin feeding on the surface of new growth before tunneling into needles. As they grow, they tunnel into shoot tips and produce protective webbing around their feeding sites. Fecal material and masses of resin accumulate on the outside of infested tips. Larval development in 2 to 4 weeks before forming a dark brown 1/4 inch long pupa in a silk cell within the tunnels produced by larvae. The pupae wriggle out prior to
adult moth emergence, leaving the empty pupal skin in the end of the tunnels. In central Texas, four to five generations may occur per year with overlapping generations occurring in the fall, while in north Texas there may be only two.
Habitat and Food Source(s): Caterpillars have chewing mouthparts. Adults have siphoning mouths. This species is the main pest of Texas grown Virginia pines produced as Christmas trees. It also attacks other young southern pine trees, with shortleaf and loblolly pines less than 15 feet tall most susceptible to attack, and is a serious pest in seed orchards and forest tree nurseries. Adults can be trapped using commercially available pheromone (sex attractant) baits or at lights.
Pest Status: Caterpillars tunnel through the shoots and tips of pine host plants, causing death of injured tips and resulting in distorted and retarded growth of these trees; medically harmless.
Damage: Injured buds and shoots of pines turn brown and die. Afterwards, tree growth can be stunted or deformed as new shoots grow around damaged shoots, producing branched growth referred to as “crow’s footing.” Trees so deformed have a lower value and can be unsightly.
Literature: Carter et al. 1980. Robinson 1984.