NC State Extension Publications

Description and Biology

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Nantucket pine tip moths, Rhyacionia frustrana, are about 1/4 inch long with a wing span of about 1/2 inch. They are copper colored with silvery markings. The eggs are very small, convex, and white to orange. Their 3/8 inch long caterpillars are usually cream colored with brown heads. Pupae are brown to dark brown, fusiform, and about 1/4 inch long. The Nantucket pine tip moth is an important pest of piine plantations. Here in North Carolina, this pest overwinters as pupae in hollowed out pine shoots. On warm days as early as January and February, new moths emerge to mate. Females lay eggs on needles, stems, and buds. Depending on the weather, 5 to 30 days later, tiny caterpillars hatch and feed on the surface of new growth or they bore into the needle bundles. Later they migrate to the shoot tips, construct protective webs at the base of buds, and begin to bore into the bud or stem. Feeding continues inside until the caterpillars are fully grown in 3 to 4 weeks. The caterpillars then pupate inside the damaged stem. Here we have at least three generations each year.

Nantucket pine tip moth

Nantucket pine tip moths are small and coppery.

Nantucket pine tip moth egg

Nantucket pine tip moth eggs are very tiny and convex.

Very young Nantucket pine tip moth caterpillars feed on pine nee

Very young Nantucket pine tip moth caterpillars feed on pine needles.

Nantucket pine tip moth caterpillar

Nantucket pine tip moth caterpillars are usually found inside damaged tips.

Nantucket pine tip moth pupae

Nantucket pine tip moth pupae are found within hollowed stem tips.

Host Plants

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Long leaf and eastern white pines are resistant to Nantucket pine tip moths, and slash pine is rarely attacked. All other pines seem to be susceptible. Here in North Carolina, loblolly and shortleaf pines are particularly favored hosts. Boring into the tips causes slower growth, crooking and forking of main stems, reduction of cones, and in extreme cases, death of young trees. Most attacks occur on trees up to 15 feet tall. Rarely, wide spread damaging infestations have been reported in larger trees.

Nantucket pine tip moths usually kill stem tips

Nantucket pine tip moths usually kill stem tips and very young cones.

Eventually Nantucket pine tip moths cause distorted

Eventually Nantucket pine tip moths cause distorted, bunchy growth or even death.

Residential Recommendations

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More than 30 species of parasites attack the Nantucket pine tip moth as well as several predatory insects and birds. Only when these natural control agents fail will it be necessary to apply an insecticide. A good way of timing sprays for this pest is to put some infested tips into a dry plastic bag and keep them in the shade. When the first little, coppery-silvery moth is seen, then the trees should be sprayed 10 days later. This 10 day waiting period allows the moths to emerge, mate and lay eggs and the eggs to hatch. That way, the pesticide is applied when the caterpillars are in their most vulnerable state. One of the Bacillus thuringiensis pesticides, pyrethroid insecticides, or Sevin will need to be applied 8 and 12 days after the first moths are noticed to obtain good control. This is an abundant pest in the landscapes of North Carolina and the moths are strong fliers. For complete control, it may be necessary to spray the trees each year until they get 15 to 18 feet tall.

References

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For assistance with a specific problem, contact your local Cooperative Extension Center.

This Factsheet has not been peer reviewed.

Author

Professor Emeritus
Entomology and Plant Pathology

Publication date: Aug. 8, 2017
Revised: Oct. 7, 2019

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