Asian Longhorned Beetle and Wood Packaging Pathways

The Asian longhorned beetle (Anoplophora glabripennis, ALB) is a wood-boring insect native to China and Korea that kills healthy hardwood trees from the inside. It reached North America and Europe in solid-wood packaging from China, and its discovery in Brooklyn, New York in 1996 was one of the events that drove the adoption of ISPM 15.

The pest

ALB is a large, glossy black beetle with irregular white spots and black-and-white banded antennae that can be longer than its body. Adult males are about 25 mm (1 in) long and females about 35 mm (1.4 in), excluding antennae.

Its preferred hosts are maples (Acer), horse chestnuts and buckeyes (Aesculus), birches, willows and elms. Poplar, ash and a range of other broadleaf trees are attacked occasionally. This breadth matters: unlike pests that need one particular tree, ALB can colonize street trees, parks and forests across temperate regions.

The life cycle is the source of the danger:

1. Females chew shallow pits in the bark of living trees and lay an egg in each, from summer into autumn.
2. Eggs hatch in roughly two weeks, and larvae bore into the cambium and then deep into the heartwood, feeding for months.
3. Larvae pupate inside the wood and adults chew round exit holes about 10 mm across, leaving the tree to feed on twigs and leaves and to mate.
4. In the United States one generation usually develops per year; in cooler climates development can take longer.

Repeated attacks cut the tree's water and nutrient flow, weaken limbs and eventually kill it. Because larvae live inside the wood, infested material shows few signs from outside until adults emerge.

PHOTO 1ALB adult beetle on a maple branch next to a round exit hole in the trunkassets/img/rehber/asian-longhorned-beetle-1.jpg

How it traveled: wood packaging

The beetle is poorly suited to long natural spread; adults seldom fly far. Its international travel was almost entirely human-assisted. Larvae and pupae in untreated pallets, crates and dunnage from Asia survived sea freight, and adults emerged at or near their destination.

Published datasheets from the European and Mediterranean Plant Protection Organization (EPPO) and plant health agencies link ALB introductions in both the US and Europe to wood packing material imported from China. The species has also been intercepted at ports of entry on multiple occasions, mostly on shipments from China.

Timeline of introductions

Some infestations have been declared eradicated, including Islip on Long Island in 2011, but eradication takes years of surveys and can require removing all infested and high-risk host trees within a regulated zone.

Eradication and costs

Because there is no reliable cure for an infested tree, eradication programs rely on:

• Tree removal: cutting and chipping or burning infested trees and, in many programs, nearby host trees at risk.
• Chemical treatment: systemic insecticides injected or applied to uninfested trees in the regulated area as a protective measure.
• Surveys: trained climbers and ground crews inspecting trees for egg sites and exit holes, often for several years after the last detection.
• Quarantines: restricting movement of host material, such as firewood and logs, out of regulated zones.

These programs involve thousands of trees and many years of work in the affected cities. Public budgets and the loss of urban shade trees are the visible costs; the long-term economic exposure also includes forest product industries and hardwood-based sectors such as maple syrup.

From outbreak to ISPM 15

The first interceptions and outbreaks in the 1990s led the United States to adopt interim rules for wood packaging from China in 1998. Other countries adopted similar measures, and in 2002 the International Plant Protection Convention published ISPM 15, which requires approved treatment, debarking and marking of wood packaging in international trade. The datasheet record notes that ISPM 15 was published as the international response to this pathway.

The key requirements that interrupt the ALB pathway are:

• Treatment. Heat to a core temperature of 56°C for 30 minutes kills larvae and pupae in the wood; see heat treatment.
• Debarking. Bark crevices are egg-laying sites, so debarked wood is less attractive; see the debarking rule.
• Marking. The IPPC mark proves treatment to inspectors; see the ISPM 15 mark.

New outbreaks still occur, and the species remains a target of surveillance in North America and Europe.

Other pathways and ongoing risk

ISPM 15 reduces but does not eliminate the risk. Remaining pathways include:

• Non-compliant or counterfeit-marked packaging, found at inspection; see what happens when packaging fails inspection.
• Dunnage and bracing that is unmarked or reused; see dunnage rules.
• Live plants and nursery stock from infested regions.
• Movement of firewood from within quarantine areas.

The species also illustrates a related pest group. The ALB belongs to the longhorn beetles (Cerambycidae), as does the vector of the pinewood nematode, and several other longhorn and borer species travel in the same pathway.

PHOTO 2Infested maple tree with exit holes in the trunkassets/img/rehber/asian-longhorned-beetle-2.jpg

Frequently asked questions

Sources

1. Anoplophora glabripennis datasheet (EWBBB 2014) — Purdue CAPS / Exotic Wood Borer and Bark Beetle National Survey
2. ISPM 15: Regulation of wood packaging material in international trade (2009) — International Plant Protection Convention (FAO)
3. Wood Packaging Material — USDA APHIS
4. Wood Packaging Material Enforcement Regulations (November 2025) — American Lumber Standard Committee