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Exotic wood-boring beetles in British Columbia: Interceptions and establishments

L.M. Humble¹, E.A. Allen¹, and J.D. Bell^2
1 Natural Resources Canada, Canadian Forest Service, 506 West Burnside Road, Victoria, British Columbia, Canada V8Z 1M5
² Canadian Food Inspection Agency, Regional Program Office, 202-620 Royal Avenue, New Westminster, British Columbia, Canada V3L 0Y9
 

Abstract:

The low grade wood and wood products used to support, brace or package commodities during shipment provide a pathway for the global movement of bark and wood- boring beetles. Immature stages of bark and wood-boring insects present within the wood used in such packaging can complete their development and emerge as adults after the commodity has arrived in Canada. Storage of commodities packaged or shipped with low grade wood products near forested lands or the disposal of wood packaging in or near natural forest provides an avenue for the introduction and establishment of non-indigenous bark and wood boring insects. Research results are presented which demonstrate that introductions of "exotics" are ongoing and that these non-indigenous bark and wood-boring species continue to establish and accumulate in the forests of Canada.

Non-Indigenous Wood-borers in Packing Materials and Dunnage

Detections of non-indigenous bark and wood-boring beetles in or emerging from the wood and wood products used to crate, brace or package commodities during shipment demonstrate the potential of this pathway for the accidental introduction and subsequent establishment of non-indigenous pest species into Canadian forests.

Recent Interceptions of Bark or Wood-boring Beetles

Living larvae or adults of four species of bark or wood-boring beetles were found in these logs used as dunnage.

Detecting Non-indigenous Bark and Wood-boring Beetles

In 1997, a collaborative research program to detect "exotic" introductions was undertaken by the Canadian Forest Service and the Canadian Food Inspection Agency. It included:

1. a survey of import warehouses using Lindgren® funnel traps andcommercially available attractants;
2. a detection survey of wood packing materials;
3. and a quarantine rearing program for wood packing materials suspected of containing live bark- and wood-borers.

Some of the non-indigenous species detected are listed in the following table:

Historically, non-indigenous introductions have occurred most frequently at ports of entry, where the goods were off-loaded, repackaged and shipped to their final destination The increased use of containers for the international shipment of commodities has the potential to alter this pattern. Containerized commodities can be shipped directly and rapidly to an end-user anywhere within the country. This efficiency of movement has the potential to result in introductions of non-indigenous bark and wood-boring insects anywhere within the country.

Establishment of Non-Indigenous Bark and Wood-borers in British Columbia

In 1995, the Canadian Forest Service began a study to determine the extent to which non-indigenous bark and wood-boring insects had invaded urban forests of the greater Vancouver area. A beetle trapping program using Lindgren® funnel traps was established in two protected forested areas: in the mixedwood forest of the Richmond Nature Park, an 80 ha urban park containing the last remnant of the Greater Lulu Island Bog; and in the deciduous and coniferous hedgerows and forest of the 300 ha Alaksen National Wildlife Area on Reifel and Westham Islands at the mouth of the Fraser River.

Examination of the trap collections from these two research sites has led to the discovery that an additional six "exotic" species of bark or wood-boring beetles are established in British Columbia. These results have doubled the number of non-indigenous species of Scolytidae (bark and ambrosia beetles) now known to occur in the province.

Initial rearings of Scolytidae from dead and dying native trees collected at two locations in the lower mainland indicate that, of the species emerging from attacked alder, birch and bigleaf maple stems, the newly discovered non-indigenous species predominate.

One of the recently introduced species discovered in this study originates from the subtropics, two species likely arrived from temperate Europe, two species are native to temperate NE Asia and one was introduced from eastern North America.

Xylosandrus germanus

The global movement of bark and wood-boring beetles.