Taxonomy

Domain	Eukarya
Kingdom	Animalia
Phylum	Arthropoda
Subphylum	Hexapoda
Class	Insecta
Subclass	Pterygota
Infraclass	Neoptera
Superorder	Holometabola
Order	Lepidoptera
Superfamily	Tortricoidea
Family	Tortricidae
Subfamily	Olethreutinae
Tribe	Eucosmini
Genus	Rhyacionia

Scientific Name

Rhyacionia frustrana

Common Name

Nantucket pine tip moth

Author: Scott M. Salom, Virginia Polytechnic Institute and State University

Distribution and Hosts

The Nantucket pine tip moth Rhyacionia frustrana occurs from southern New England to Florida, west to Texas and Arkansas, and was recently introduced into southern California. In Virginia, it is found predominantly in the eastern part of the state. Most two and three needled pine species are susceptible to attack. Among the southern pines, Shortleaf, Loblolly, and Virginia Pines are the most susceptible. Scots and Pitch Pines are also subject to attack. Slash Pine is highly resistant and Longleaf Pine is virtually immune to attack.

Description of Damage

Tip moth larvae attack developing shoots of young pines and may cause serious damage, resulting in severe stunting and stem deformation, and in extreme cases death to the host. Loss of tree form is common where heavy attacks result in forks, crooks, or multiple trunks. Damage is most severe on seedlings and saplings under five years of age. Trees grown for special purposes, such as Christmas trees, seed orchards, and progeny tests are often regarded as high risks for tip moth attack. In addition, attacks can also reduce cone crops by injuring conelets and killing potential cone-bearing shoots.

Identification

Adult moths are small (wing length = 4 to 7 mm and wing spread = 12 mm); the head, body, and appendages are covered with gray scales; and the forewings are reddish-brown with silver-gray markings. Eggs are yellow in color, and usually are laid singly. Young larvae are cream colored with black heads. Mature larvae are light brown to orange and about 9 mm long.

Life History

Tip moth has two to five generations per year throughout its range, with two to three generations occurring in Virginia. Adult emergence for each generation is synchronized with new growth flush from its primary host. The first two generations are discernible, yet overlap occurs in the third generation. Winter is spent as a pupa within the injured tips of the host. In Virginia, adults emerge from late March to mid-April. Mating occurs soon after emergence and is mediated by a sex pheromone (female produced chemical that attracts males). Eggs are deposited on shoots and needles, and then hatch within 14 days. First instar larvae frequently mine inside needles, shoots, and buds. Second instar larvae feed at needle and bud axils, where they construct a tent of silk covered with resin. Subsequent instars feed inside buds and shoots. Second generation adults emerge five to six weeks after the first generation adults. Third generation adults emerge from late July to early August.

Control

For forest stands, preventive measures such as planting more than one tree species, diversifying stand structure, fertilization, and weed control would help keep tip moth populations down. Chemical control in forest stands is a last resort and is usually only economically feasible in cases where damage is especially severe and unit value of trees is high (ie. seed orchards and Christmas tree plantations). Effective use of pesticides is dependent on precise timing for spraying, which should be carried out after eggs are laid up until second instar larvae are present. Pheromone-baited traps may be used to determine time of spraying. In Georgia, trees should be sprayed ten days after the first adult moth is captured. This must be repeated for each generation. In Virginia it is likely to be slightly longer. Consult Haugen and Stephen (1984) for data on tip moth development in relation to temperature.

Systemic insecticides applied to the soil can be effective if there is adequate soil moisture for the toxicant to be incorporated by the tree roots. Foliar applications of pesticides can provide good control and are usually the least expensive. Use of biological insecticides, such as viruses or bacteria may also be feasible. There is potential in the future for control by disrupting adult communication and mating using synthetic pheromone components.

References

Berisford, C.W. 1988. The Nantucket pine tip moth. pp. 141-161. In A.A. Berryman (ed.). Dynamics of Forest Insect Popualtions. Plenum Publ. Corp.
Berisford, C.W., P.M. Gargiullo, and C.G. Canalos. 1984. Optimum timing for insecticidal control of the Nantucket pine tip moth (Lepidoptera: Tortricidae). J. Econ. Entomol. 77:174-177.
Haugen, D.A. and F.M. Stephen. 1984. Development rates of Nantucket pine tip moth, Rhyacionia frustrana (Comstock) (Lepidoptera: Tortricidae), life stages in relation to temperature. Environ. Entomol. 13:56-60.
Hill, A.S., C.W. Berisford, U.E. Brady, and W.L. Roelofs. 1981. Nantucket pine tip moth, Rhyacionia frustrana: identification of two sex pheromone components. J. Chem. Ecol. 7:517-528.
Lewis, K.R., H.M. Kulman, and H.J. Heikkenen. 1970. Parasites of the Nantucket pine tip moth in Virginia with notes on ecological relationships. J. Econ. Entomol. 63:1135-1139
Robinson, J.V. 1983. Nantucket pine tip moth in Christmas tree plantations. pp. 59-61. In T.L. Payne, R.F. Billings, R.N. Coulson, and D.L. Kulhavey (eds.). History, Status, and Future Needs For Entomology Research in Southern Forests. Proc. 10th Anniv. E. Texas Forest Entomology Seminar. Kurth Lake, TX.

External links

Salom, S. Nantucket Pine Tip Moth. ENTOMOLOGY PUBLICATION 444-238, August 1996.

Importance

This bud and shoot borer occurs throughout the East and South. Most species of pines are attacked, except longleaf and eastern white pine. Greatest economic losses result from retarding the height growth and deforming the main stems of trees in plantations. In pine seed orchards this pest kills female flowers and conelets.

Identifying the Insect

Young larvae are cream colored with black heads. Mature larvae are light brown to orange and about 2/5 inch (9 mm) long. The head, body, and appendages of the moth are covered with gray scales, while the forewings are covered with patches of brick-red and coppercolored scales.

Identifying the Injury

Tip moths injure the growing shoots of young pines. Larvae bore into and feed on inner tissues of buds and shoots. Shoot injury occurs primarily during the first 5 years and decreases as crowns close. In seed orchards, boring frass, on the conelet surface and dead stalk, is the first indication of attack.

Biology

This pest overwinters as a pupa, and adults emerge in late winter or early spring. Mating and egg laying occur shortly after emergence. Early larvae feed on needles and surfaces of new growth, while later larvae move to shoot tips and begin boring into buds or stem tissues. Pupation occurs within damaged shoots. There are 2 to 5 generations per year.

Control

Control by insecticides is usually not recommended except for high value trees in seed orchards, nurseries, Christmas tree plantations, or for ornamentals

Gallery

References

Insects and Diseases of Trees in the South. 1989. USDA Forest Service - Forest Health Protection. R8-PR16. 98 pp. Taken from http://fhpr8.srs.fs.fed.us/forstpst.html